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Background: Aerobic fitness is of great value for reducing risk of mortality and cardiovascular diseases. Objective: This study evaluated the performance in and correlations between a new test (five-minute pyramid test, 5MPT), the six-minute walk-test (6MWT) and maximal oxygen uptake (VO(2max)) among old and young adults. Methods: Forty-four habitually active adults (females and males), 23 old (64-79 years) and 21 young (20-32 years) participated. In the 5MPT, the participants moved back and forth along a short walkway (5.5 m) over boxes (height: 'old people' 0.42 m, 'young people' 0.62 m) arranged like an elongated step pyramid for 5 min. Power in the pyramid test (5MPT(power)) was calculated as the product of numbers of laps, body weight, gravity and highest box level divided by time. A 6MWT and a maximal cycle ergometer test for direct measurements of VO(2max) were also performed. In all tests heart rate, with on-line electrocardiography, and perceived exertion were recorded. Results: There was a strong correlation between the 5MPT(power) and VO(2max) for the entire group studied (r = 0.98), and each of the four subgroups old and young females and males separately (r = 0.78-0.98). Contrary to several earlier studies, especially involving people with various diseases, the present data showed that 6MWT cannot be used to predict VO(2max) among old females and young adults. The correlation with VO(2max) was weaker for the 6MWT than for the 5MPT(power). The relative performance values for the old compared to the young (ratio old/young × 100) were considerably lower in 5MPT(power) and VO(2max) (47-55%) than in distance and 'work' in the 6MWT (82-86%). Conclusions: The results, with age and gender variations, can be valuable information in health-fitness contexts, since measuring physical aerobic capacity is very significant in connection with risk evaluations of mortality and various diseases. The 5MPT is a rapid, functional, easy and inexpensive tool for predicting assessed maximal aerobic power.

En god kondition och styrka har samband med förbättrad hälsa, minskad förekomst av flera folksjukdomar samt ökad livslängd. Fysiologiska tester kan vara stimulerande för äldre att följa utvecklingen av sin fysiska kapacitet och för olika aktörer som vill göra hälsoutvärderingar.

Aim. This study evaluates the results of and correlations between the six-minute walk-test (6MWT) and a maximal oxygen uptake (VO2max) test among physically active young adults.

Methods. Sixty-three adults (33 females and 30 males) aged 18-38 years participated. 6MWT and a maximal running treadmill test for measurements of VO2max were performed. 6MWT reliability was also evaluated.

Results. Mean distance in the 6MWT for the females was 848 (685-976) m and for the males 866 (704-1077) m. The gender differences were considerably less for the 6MWT (2%) than in the VO2max test, both normalized to body weight (21%) and in absolute form (35%). The mean values, for the female and male subjects in the VO2max were 46.7 and 58.9 ml/kg/min and 2.94 and 4.53 l/min, respectively. The data showed a very low, not significant, correlation (r=-0.02-0.32) between walking distance in the 6MWT and VO2max.

Conclusions: The 6MWT-distance for this physically active young adult group, which previously not has been studied, was considerably higher than in earlier reports for various other groups. In contrast to several prior studies, especially involving people with various diseases, the present data, on healthy active adults, showed that distance in the 6MWT cannot predict maximal oxygen uptake. The present results may be related to the low potential of walking as a locomotor form to tax the cardio-respiratory system sufficiently for this group. Since aerobic capacity is correlated with increased survival, these new data and given comparisons with previous reports are specially valuable when evaluating fitness in various sports and health contexts. 

Background: Higher physical capacity is correlated with increased health. Knowledge in this area regarding psychiatric diseases is sparse. 

Purpose: The aim was to study aerobic and several strength capacities in a physical activity project for persons with depression or anxiety.

Methods: Eighty-four persons (56 women and 28 men) with depression or anxiety were recruited from psychiatric out-patient clinics in Stockholm. Their mean age and BMI was 46 (21-80) years and 26 (17-41) kg/m², respectively. 50% were sick-listed. 50% had BMI>25. Aerobic and strength tests were chosen by each subgroup´s project leaders. Directed physical activity was given, in groups 10-15, 1 hour twice/week during 8-12 weeks.

Results: Significant changes (p<0.05, of all n=84) between pre- and post tests were seen in submaximal cycle test (11% enhanced values, n=56) and distance of 6 minutes walk test (16%, n=15) as well as in strength tests for the back for the back (i.e. time in static horizontal belly-back, 40%, n=44), abdominal and hip flexors (i.e. number of hip flexion sit-ups, 45%, n=38), leg (i.e. standing with 90^O in hips and knees, 48%, n=56) and arm with shoulder muscles (i.e. number of raising weights alternately with the arms, 46%, n=32). Hand grip tests, BMI or blood pressure values did not change significantly.

Conclusions: Directed 8-12 weeks physical activity programs can improve physical fitness in individuals with depression or anxiety.

PURPOSE: The aim was to introduce and evaluate the reliability and validity of an active hamstring flexibility test as a complement to common clinical examination when determining safe return to sport after hamstring injury.

METHODS: Eleven healthy subjects (28 years) were tested on repeated occasions, and 11 athletes (21 years) with MRI-verified acute hamstring strain were tested when common clinical examination revealed no signs of remaining injury, i.e. there was no differences between the legs in palpation pain, manual strength tests, and passive straight leg raise. Flexibility, i.e. highest range of motion of three consecutive trials, was calculated from electrogoniometer data during active ballistic hip flexions and conventional passive slow hip-flexions in a supine position. A VAS-scale (0-100) was used to estimate experience of insecurity during active tests.

RESULTS: No significant test-retest differences were observed. Intra-class correlation coefficients ranged 0.94-0.99 and coefficients of variation 1.52-4.53%. Active flexibility was greater (23%) than passive flexibility. In the athletes, the injured leg showed smaller (8%) active, but not passive, flexibility than the uninjured leg. Average insecurity estimation was 52 (range 28-98) for the injured and 0 for the uninjured leg, respectively.

CONCLUSION: The new test showed high reliability and construct validity; furthermore, it seems to be sensitive enough to detect differences both in active flexibility and in insecurity after acute hamstring strains at a point in time when the commonly used clinical examination fails to reveal injury signs. Thus, the test could be a complement to the common clinical examination before the final decision to return to sport is made.

This study aimed to evaluate biomechanics during seated double-poling exercises in individuals with spinal cord injury (SCI) and to compare these with those of able-bodied persons (AB). 26 participants volunteered for the study; 13 with SCI (injury levels C7-T12), and 13 AB. A seated double-poling ergometer (SDPE) was developed. 3-dimensional kinematics was measured and piezoelectric force sensors were used to register force in both poles for calculation of power during incremental intensities. Significantly lower power outputs, (143.2 ± 51.1 vs. 198.3 ± 74.9 W) and pole forces (137.1 ± 43.1 vs. 238.2 ± 81.2 N) were observed during maximal effort in SCI compared to AB. Sagittal upper trunk range of motion increased with intensity and ranged from 6.1–34.8 ° for SCI, and 6.9–31.3 ° for AB, with larger peak amplitudes in flexion for AB (31.4 ± 12.9 °) compared to SCI (10.0 ± 8.0 °). All subjects with SCI were able to exercise on the SDPE. Upper body kinematics, power and force outputs increased with intensity in both groups, but were in general, lower in SCI. In conclusion, the SDPE could be successfully used at low to high work intensities enabling both endurance and strength training for individuals with SCI.

Sammanfattning

Ett sammanfattande porträtt av den nyantagna lärarstudenten vid GIH med utgångspunkt från enkätsvaren ger vid handen en bild av en person, som är ca 21 år gammal, född i Sverige och uppvuxen i en medelstor stad i Mellansverige. Studenten trivdes mycket bra i skolan och var som elev något över medel med MVG i idrott och hälsa.

Valet av yrkesutbildning grundade sig på ett stort intresse för idrott, samt en önskan att få jobba med barn och ungdom. Studievalet hade för många påverkats av en tidigare idrotts-lärare, kompisar och familj. En bra lärare i idrott och hälsa är enligt studenten positiv, engagerad, rättvis, bestämd och kunnig.

Lärarstudenten ser sig behärska bollspel väl. Störst kunskap och färdighet uppges i fot-boll och alpin skidåkning. Minst kunskap och färdighet skattades i softboll, baseboll, bergsklättring, långfärdsskridskoåkning och i konsten att kunna valla skidor. Många ser sig ha god kunskap om sambandet mellan hälsa, livsstil och miljö, men mindre god om hur en idrottsaktivitet har betydelse för kulturarvet, samband mellan miljö och männi-skans hälsa i ett historiskt och nutidsperspektiv samt i ergonomi.

På sin fritid går lärarstudenten ofta på idrottsevenemang, café, tittar på TV och video eller umgås med vänner och familj. Lärarstudenten går sällan på bio och nästan aldrig på tea-ter, museum eller vernissager. "Vad är vernissage?" undrar en student.

Hälsan, både fysiskt och psykiskt, skattas som tillfredsställande och man känner ofta hopp, glädje och meningsfullhet. Emellertid finner man sig även ofta stressad på grund av tidsbrist och alla krav. Många kvinnliga studenter (41%) rapporterade ryggont och många, både kvinnor och män, beskrev att de har besvär från en skadad fotled eller knä. De flesta lärarstudenterna är regelbundet fysiskt aktiva och de finner att mängden motion delvis är tillfredsställande.

Förväntningarna är höga på utbildningen både att den är mångsidig och kommer att ge ökad kunskap inom olika områden. Under studietiden förväntar man sig att utvecklas och förbättra sin egen fysiska status och hälsa. En student uttrycker det med orden: "Mitt nya liv startar idag". Den sammanfattande bilden av lärarstudenten på GIH liknar den som tidigare har redovisats av Meckbach och Wedman i en liknande studie från maj 2005. Deras studie genomfördes på studenter efter ett års studier på GIH (Meckbach & Wed-man, 2007).

BACKGROUND: The aim of this study was to compare linear position transducer force plate-based methods and more complex combinations of those for calculation of power output in loaded squat jump.

METHODS: Eight methods were used simultaneously in data collection: vertical ground reaction force (VGRF), ground reaction forces (GRF), 1 linear position transducer (1LPT), 1LPT and VGRF (1LPT+VGRF), 2 linear position transducers (2LPTs), 2LPTs and VGRF (2LPTs+VGRF), 5 linear position transducers (5LPTs), 5LPTs and GRF (5LPTs+GRF). Power output was calculated for each lift according to the sensor or sensors used and the results were compared.

RESULTS: Power output calculated separately with LPTs and GRF method did not differ significantly from combined methods such as 1LPT+VGRF, 2LPTs+VGRF. No significant differences were found when comparing power output between 5LPTs+GRF and combined methods such as 2LPTs+VGRF.

CONCLUSIONS: This study indicates that test methodology with a simple single linear position transducer setup and or force platform suffice when recording vertical jump such as loaded squat jump.

BACKGROUND: Previously, it was shown that elite soccer teams were 24% more likely to win matches if their passing effectiveness were increased by 1%. However, research interventions aiming to improve passing performance are scarce. The current study aimed to investigate the effect of a short technique-intense training period on side-foot kick performance among elite female soccer players.

METHODS: Four side-foot kick tests were completed before and after a training period: kicking a stationary ball using match-relevant (SBRS) and maximal ball speed (SBMS), passing the ball on the move using match-relevant ball speed (RBRS), and repeated side-foot kicks onto a rebound-box with continuously increasing passing distance (RRB). The players were assigned to either the intervention group or the control group. The training intervention consisted of six 55-min training sessions with five side-foot kick exercises. Within-group and between-group differences were investigated using paired-samples t-test and Mann-Whitney U test, respectively.

RESULTS: The intervention group improved the performance in the RBRS and RRB tests (both P < 0.05), but no differences were found for the SBRS and SBMS tests (both P > 0.05). No improvements were found for the control group independent of test condition (all P > 0.05). Significant between-group differences were found for the RBRS and RRB tests (both P < 0.05), whereas no differences were found for the SBRS and SBMS tests (both P > 0.05).

CONCLUSIONS: The fundamental soccer skill of passing a moving ball was improved in elite female soccer players by a short technique-intense training period.

THE EFFECT OF TRAINING ON SIDE FOOT-KICK PERFORMANCE AMONG SWEDISH FIRST LEAGUE WOMEN’S SOCCER PLAYERS

Carlsson, M.1, Isberg, J.1, Nilsson, J.1, Carlsson, T.1 1: Dalarna University (Falun, Sweden)

Introduction

A high completion rate for passes is important for success in soccer, because longer passing sequences are related to more scored goals (Hughes & Franks, 2005). In a recent study, it was found that female players had a lower pass-completion rate than male players at the highest competitive standard of European soccer, which suggests that elite female players in general do not have the same technical characteristics as elite male players (Paul S. Bradley et al., 2014). The purpose of the study was investigate the effect of a 2-week training intervention on side foot-kick performance among Swedish first league women’s soccer players.

 Methods

To investigate the effect of training on side foot-kick performance, a pre-post-intervention study was implemented where four side foot-kick tests were performed before and after a 2-week training period. The side foot-kick accuracy were investigated when kicking a stationary ball using match-relevant ball speed (SBRS) and maximal ball speed (SBMS) as well as subsequent to a 5-m run with the ball from different approach angles (0°, 30°, and 60°) to a predetermined position, where passing of the ball on the move was executed using match-relevant ball speed (RBRS). The fourth test comprised repeated side-foot kicks onto a rebound-box with continuously increasing passing distance (RRB).

Based on the results from the pre-tests, the players were assigned to either the intervention group (INT) or the control group (CON). The training intervention consisted of six 55-min training sessions. In each session, two rounds of five exercises focusing on improvement of side foot-kick accuracy were executed. Within-group and between-group differences were investigated using paired samples Student’s t-tests and Mann-Whitney U tests, respectively.

Results

Prior to the training intervention, there were no significant differences between the groups for any of the investigated test variables. The INT group improved RBRS (P = 0.036) and RRB (P = 0.010) during the training intervention, whereas no significant within-group changes were found for either SBRS or SBMS (both P > 0.05). No within-group differences were found for any of the test variables in the CON group (all P > 0.05). Significant between-group differences were found for RBRS (P = 0.040) and RRB (P = 0.005), whereas no differences were found for either SBRS or SBMS (both P > 0.05).

Conclusion

The fundamental soccer skill of passing a moving ball could be improved in elite women players by a 2-week training period focusing on improving   side foot-kick performance.

References

Bradley PS, Carling C, Diaz AG, Hood P, Barnes C, Ade J, Boddy M, Krustrup P, Mohr M (2013) Hum Mov Sci, 32, 808-821.

Hughes M, Franks I (2005) J Sports Sci, 23, 509-514.

The purpose of this study was to investigate the effect of ball temperature on impact ball speed and carry distance during golf drives in a blind randomized test design. The balls were exposed to a temperature-controlled environment (4 °C, 18 °C, 32 °C, and 46 °C) for 24 h prior to the test and each temperature group consisted of 30 balls. The 120 drives were performed by an elite male golfer (handicap: 0.0) in an indoor driving range. All drives were measured by a Doppler-radar system to determine the club-head speed, launch angle, spin rate, ball speed, and carry distance. Differences between the groups were investigated using a one-way analysis of variance. The results indicated that ball-speed and carry-distance differences occurred within the four groups (p < 0.001 and p < 0.01, respectively). The post hoc analyses showed that the ball temperatures of 18 °C and 32 °C had greater ball speeds and carry distances than balls at 4 °C and 46 °C (all p < 0.05). The intervals for the between-group differences were 0.6–0.7 m s⁻¹ and 2.9–3.9 m for ball speed and carry distance, respectively. Hence, the results showed that ball temperature influences both the ball speed and the carry distance. Based on the findings in this study, standardization of ball temperature should be factored into governing body regulation tests for golf equipment.

THE EFFECT OF BALL TEMPERATURE ON BALL SPEED AND CARRY DISTANCE IN GOLF DRIVES

Carlsson, T.1, Nilsson, J.1,2, Hellström, J.3, Tinmark, F.2, Carlsson, M.1. 1: Dalarna University (Falun, Sweden), 2: The Swedish School of Sport and Health Sciences (Stockholm, Sweden), 3: The Swedish Golf Federation (Stockholm, Sweden). 

Introduction

Previously it was reported that golf-ball temperature has influence on the golf balls’ coefficient of restitution, impact duration, and maximal deformation (Allen et al., 2012). They concluded that their research was the first step in a process for determining the effect of temperature on a golf drive. However, how large influence the golf-ball temperature has on golf drives remains to be investigated. The purpose was to investigate the effect of ball temperature on impact ball speed and carry distance during golf drives in a blind randomized test design. 

Methods

The balls were exposed to a temperature-controlled environment (4°C, 18°C, 32°C, and 46°C) for twenty-four hours prior to the test, and each of the four different ball-temperature groups consisted of 30 balls. The 120 drives were performed by an elite male golfer (handicap: 0.0) in an indoor driving range. All drives were measured by a Doppler-radar system to determine club-head speed, launch angle, spin rate, ball speed, and carry distance. Differences between the four ball-temperature groups were investigate using a one-way analysis of variance. 

Results

The results indicate that there are ball-speed and carry-distance differences within the four ball-temperature groups (P < 0.001 and P < 0.01, respectively). The post-hoc analyses showed that the ball temperatures 18°C and 32°C had both greater ball speeds and carry distances compared to the balls in the ball-temperature groups 4°C and 46°C (all P < 0.05); the intervals for the between-group differences were 2.0 to 2.4 km/h and 2.9 to 3.9 m for ball speed and carry distance, respectively.

Conclusion

The novel results of the current study show that the ball’s temperature has a significant effect on the ball speed after club-head impact and carry distance for drives performed by an elite golfer. The ball temperatures 18°C and 32°C gave significantly increased ball speeds and carry distances compared to the ball-temperature groups 4°C and 46°C. This knowledge could be used to maximise the carry distance and/or to minimise the carry-distance variability related to ball temperature.

REFERENCES:

Allen T, Bowley A, Wood P, Henrikson E, Morales E, James D. (2012) Procedia Eng, 34, 634-639.

Purpose

To compare the effects of strength training versus ski-ergometer training on double-poling gross efficiency (GE), maximal speed (Vmax), peak oxygen uptake (V&#x02D9;O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak) for elite male and female junior cross-country skiers.

Methods

Thirty-three elite junior cross-country skiers completed a 6-week training-intervention period with two additional 40-min training sessions per week. The participants were matched in pairs and within each pair randomly assigned to either a strength-training group (STR) or a ski-ergometer-training group (ERG). Before and after the intervention, the participants completed three treadmill roller-skiing tests to determine GE, Vmax, and V&#x02D9;O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak. Mixed between-within subjects analysis of variance (ANOVA) was conducted to evaluate differences between and within groups. Paired samples t tests were used as post hoc tests to investigate within-group differences.

Results

Both groups improved their Vmax and V&#x02D9;O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak expressed absolutely (all P < 0.01). For the gender-specific sub-groups, it was found that the female skiers in both groups improved both Vmax and V&#x02D9;O2peak" role="presentation" style="box-sizing: border-box; display: inline-table; line-height: normal; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">V˙O2peakV˙O2peak expressed absolutely (all P < 0.05), whereas the only within-group differences found for the men were improvements of Vmax in the STR group. No between-group differences were found for any of the investigated variables.

Conclusions

Physiological and performance-related variables of importance for skiers were improved for both training regimes. The results demonstrate that the female skiers’ physiological adaptations to training, in general, were greater than those of the men. The magnitude of the physiological adaptations was similar for both training regimes.

Bakgrund och syfte. Syftet med hälsoprojektet under 8-12 veckor för äldre är att ge ledarledd fysisk aktivitet 2 gånger/vecka samt att utvärdera upplevd hälsa, förändring av livsstilssvanor samt fysisk kapacitet. Hälsoprojektet är ett fortlöpande samarbete mellan Solna stad och Gymnastik- och idrottshögskolan (GIH) och utförs under vårterminerna sedan ett flertal år.

Metod. Individerna anmäler sitt deltagande själva. Det kostnadsfria hälsoprojektet utförs inom undervisningen i Folkhälsa i regi av GIH-studenter under handledning av verksamhetschefen i Solna stad och lärare/läkare på GIH. Den ledarledda fysiska aktiviteten utgörs primärt av stavgång, motionsgymnastik, vattengymnastik samt styrketräning. Initialt och i slutet av perioden besvarar deltagarna en hälsoenkät angående upplevd hälsa och livsstilsvanor om fysisk aktivitet, kost, sömn, rökning och alkohol samt utför några olika fysiologiska tester i samband med ett hälsosamtal.

Resultat. Exempel på sammanställda resultat ges här för de 117 äldre som fullföljde hela projektet under en vårtermin (för kvinnorna var antalet samt medelvärden för ålder och BMI 99, 74år och 26 respektive för männen 18, 73år och 25). Efter avslutat projekt sågs för gruppen som helhet generellt en signifikant förbättrad upplevd fysisk och mental hälsa, kondition och styrka i buk-, ben- och armmuskulatur. För kvinnorna observerades även en ökad balansförmåga och uthållighet i ryggmusklerna. Enkätfrågorna angående fysiska aktivitetsvanor och stillasittande visade på, efter avslutat projekt, en förändring till en mer aktiv livsstil.

Slutsats/Diskussion. Således kan utvärderade 8-12 veckors hälsoprojekt med ledarledd fysisk aktivitet för äldre bidra till förbättrad upplevd hälsa, ökade fysiska aktivitetsvanor, minskat stillasittande och bättre fysiska kapaciteter såsom kondition, styrka och balans som är positivt korrelerade till ökad livslängd och minskad förekomst av en mängd olika folksjukdomar och skador. Fler projekt och studier behövs framöver med ytterligare uppföljningar, jämförelser och för att vidareutveckla olika fysiologiska tester och andra hälsoparametrar som kan ha positiva samband med ökad hälsa.

The aim was (1) to evaluate measurements of vertical displacements (V(disp)) of a single point on sacrum as an estimate of the whole body centre of mass (CoM) V(disp) during treadmill running and (2) to compare three methods for measuring this single point. These methods were based on a position transducer (PT), accelerometers (AMs) and an optoelectronic motion capture system. Criterion method was V(disp) of the whole body CoM measured with the motion capture system. Thirteen subjects ran at 10, 12, 14, 16, 18, 20 and 22kmh(-1) with synchronous recordings with the three methods. Four measurements of the (V(disp)) were derived: (1) V(disp) of CoM calculated from a segment model consisting of 13 segments tracked with 36 reflective markers, (2) V(disp) of the sacrum recorded with the PT, (3) V(disp) of the sacrum calculated from the AM, and (4) V(disp) of the sacrum calculated as the mid point of two reflective markers (sacrum marker, SM) attached at the level of the sacral bone. The systematic discrepancy between the measurements of sacrum V(disp) and CoM V(disp) varied between 0 and 1.5mm and decreased with increasing running velocity and decreasing step duration. PT and SM measurements showed strong correlation, whereas the AM showed a variability increasing with velocity. The random discrepancy within each subject was 7mm for all three methods. In conclusion single-point recordings of the sacrum V(disp) may be used to monitor changes in V(disp) of CoM during treadmill running.

The aim of this study was to investigate the reliability of a new infrared light based method (IR₄₀) for recording temporal stride patterns during treadmill running. The IR₄₀ device, emitting a tight web of 40 infrared light beams 10 mm above the treadmill running surface, was compared to a previously validated electro-pneumatic contact shoe (CS) method while nine well-trained athletes ran at 2.8, 3.3, 3.9, 4.4, 5.0, and 5.6 m s⁻¹. Disconnection and reconnection of the IR beams marked the stance phase. The sampling rate was 500 Hz for both methods. The stance phase duration was on average 11.5 (±8.4) ms longer with the IR₄₀ than with the CS depending on earlier touch down (8.3 ± 6.2 ms) and delayed toe off (3.2 ± 5.3 ms) registrations. Significantly different stance phases were recorded between all velocities and for both methods. Thus, despite the fact that the IR₄₀ systematically measured a somewhat longer stance phase duration than CS, the IR₄₀ is nonetheless useful for temporal stride analysis during treadmill running.      

The purpose was to study the validity of a recently proposed method [Forsell C, Halvorsen K. A method for determining minimal sets of markers for the estimation of center of mass, linear and angular momentum. Journal of Biomechanics 2009;42(3):361-5] for estimating the trajectory of the whole-body center of mass (CoM) in the case of running at velocities ranging from 10 to 22 kmh(-1). The method gives an approximation to the CoM using the position of fewer markers on the body than the standard method of tracking each segment of the body. Fourteen male athletes participated. A standard method for determining the CoM from a model of 13 segments and using the position of 36 markers was used as reference method. Leave-one-out cross-validation revealed errors that decreased with increasing number of markers used in the approximative method. Starting from four markers, the error in absolute position of the CoM decreased from 15mm to 3mm in each direction. For the velocity of the CoM the estimation bias was neglectable, and the random error decreased from 0.15 to 0.05 ms(-1). The inter-subject and intra-subject variability in the estimated model parameters increased with increasing number of markers. The method worked well also when applied to running at velocities outside the range of velocities in the data used to determine the model parameters. The results indicate that a model using 10 markers represents a good trade-off between simplicity and accuracy, but users must take into account requirements of their specific applications.

Syftet med denna studie var att med hjälp av en enkätmetod kartlägga blivande GIH-studenters erfarenhetsbakgrund avseende naturmiljöaktivitet, natursäkerhet och friluftsliv före utbildningen vid GIH.

I denna enkätundersökning deltog 92 studenter som just påbörjat sina studier vid Gymnastik- och idrottshögskolan (GIH) i Stockholm höstterminen 2007. Av hela studentpopulationen som deltog i undersökningen var 48 % män och 52 % kvinnor. Av hela populationen som besvarat enkäten var 48 studenter från Lärarprogrammet, 26 studenter från Hälsopedagogprogrammet och 18 studenter från Tränarprogrammet.

Enkäten introducerade följande definitioner:

Naturmiljöaktivitet – aktivitet som bedrivs i naturen t.ex. orientering, simning, skridskor eller längdskidåkning och där aktiviteten är det väsentliga.

Friluftsliv – Aktivitet och vistelse i naturmiljö i syfte att erhålla naturupplevelser samt stimulans och rekreation av psykisk och/eller fysisk art, med eller utan inslag av prestation och utan krav på tävlingsprestation. I skolan bedrivs friluftsliv alternativt naturmiljöaktivitet inom begreppet "Friluftsdag".

I enkätens inledning fick deltagarna i undersökningen svara på frågor om ålder, kön, skolbakgrund samt utbildningsort. Resterande tio frågor avsåg att kartlägga erfarenheterna av naturmiljöaktivitet och friluftsliv på fritid och i skolan (grundskola och gymnasium). Frågorna omfattade huvudsakligen kvantifierade svar men även kortfattade beskrivningar förekom som klassificerades i efterhand. Deltagarna fick även gradera sina upplevda kunskaper och färdigheter inom exempelvis olika naturmiljöaktiviteter, miljökunskap (ekologi) samt övernattning och matlagning utomhus. I den avslutande frågan kartlades deltagarnas simkunnighet.

En majoritet (ca 70 %) av både manliga och kvinnliga studenter som påbörjar sin utbildning vid GIH har endast en viss eller endast en liten erfarenhet av naturmiljöaktiviteter. Studenter från landsbygden utmärker sig inte när det gäller stor erfarenhet av naturmiljöaktivitet och friluftsliv, frekvensen är lägre hos dem som bott/studerat på landet jämfört med stadsbor. I jämförelsen rörande förekomsten av naturmiljöaktivitet i skolan och på fritiden ligger tonvikten på naturmiljöaktivitet. Endast en begränsad del av svaren representerar aktiviteter som är typiska för friluftsliv med fokus på vistelse och upplevelse av naturen. Friluftsdagarnas innehåll verkar ha divergerat så mycket att även s.k. arenaidrotter som t.ex. friidrott förekommer under friluftsdagarna.

Det är viktigt att lärare i skolan och organisationer som verkar för friluftsliv är medvetna om distinktionen mellan naturmiljöaktivitet och friluftsliv. Om enbart naturmiljöaktiviteten fokuseras finns det risk för att naturupplevelsen förflackas och friluftslivet inte blir något annat än fysisk aktivitet i naturen.

The purpose was to determine the magnitude of aerobic and anaerobic performance factors among elite male football players in different team positions. Thirty-nine players from the highest Swedish division classified as defenders (n=18), midfield players (n=12) or attackers (n=9) participated. Their mean (± sd) age, height and body mass (bm) were 24.4 (±4.7) years, 1.80 (±5.9)m and 79 (±7.6)kg, respectively. Running economy (RE) and anaerobic threshold (AT) was determined at 10, 12, 14, and 16km/h followed by tests of maximal oxygen uptake (VO2max). Maximal strength (1RM) and average power output (AP) was performed in squat lifting. Squat jump (SJ), counter-movement jump with free arm swing (CMJa), 45m maximal sprint and the Wingate test was performed. Average VO2max for the whole population (WP) was 57.0mL O2•kg-1min-1 . The average AT occurred at about 84% of VO2max. 1RM per kg bm0.67 was 11.9±1.3kg. Average squat power in the whole population at 40% 1RM was 70±9.5W per kg bm0.67 . SJ and CMJa were 38.6±3.8cm and 48.9±4.4cm, respectively. The average sprint time (45m) was 5.78± 0.16s. The AP in the Wingate test was 10.6±0.9W•kg-1 . The average maximal oxygen uptake among players in the highest Swedish division was lower compared to international elite players but the Swedish players were better off concerning the anaerobic threshold and in the anaerobic tests. No significant differences were revealed between defenders, midfielders or attackers concerning the tested parameters presented above.

The purpose was to determine running economy and lactate threshold among a selection of male elite football players with high and low aerobic power. Forty male elite football players from the highest Swedish division (“Allsvenskan”) participated in the study. In a test of running economy (RE) and blood lactate accumulation the participants ran four minutes each at 10, 12, 14, and 16 km•h-1 at horizontal level with one minute rest in between each four minutes interval. After the last sub-maximal speed level the participants got two minutes of rest before test of maximal oxygen uptake (VO2max). Players that had a maximal oxygen uptake lower than the average for the total population of 57.0 mL O2•kg-1•minute-1 were assigned to the low aerobic power group (LAP) (n=17). The players that had a VO2max equal to or higher than 57.0 mL O2•kg-1•minute-1 were selected for the high aerobic power group (HAP) (n=23). The VO2max was significantly different between the HAP and LAP group. The average RE, measured as oxygen uptake at 12, 14 and 16km•h-1 was significantly lower but the blood lactate concentration was significantly higher at 14 and 16 km•h-1 for theLAP group compared with the HAP group.

The pressure/force acting between the running surface of a ski and the snow may indirectly change glide friction. Thus, measuring the pressure/force distribution may be important for a deeper understanding of glide in skiing. The present aim was to construct a device that allowed the pressure/force underneath the ski running surface (SRS) to be recorded. Pressure sensors were attached on top of a platform. Sheets of different materials were used to improve the interaction between the SRS and the sensors. Possible functions of the device are demonstrated in three applications that emphasized comparison of force distribution underneath skis selected for similarity, force distribution under both skis and a single ski as well as backward weight distribution. The results show that the device with the pressure sensors mapped pressure/force distribution underneath the skis in the applications presented, and the system can thus be a useful tool for further optimizing e.g., ski designs.

The purpose was to investigate the contribution of leg-muscle-generated forces to paddle force and kayak speed during maximal-effort flat-water paddling. Five elite male kayakers at national and international level participated. The participants warmed up at progressively increasing speeds and then performed a maximal-effort, nonrestricted paddling sequence. This was followed after 5 min rest by a maximal-effort paddling sequence with the leg action restricted—the knee joints “locked.” Left- and right-side foot-bar and paddle forces were recorded with specially designed force devices. In addition, knee angular displacement of the right and left knees was recorded with electrogoniometric technique, and the kayak speed was calculated from GPS signals sampled at 5 Hz. The results showed that reduction in both push and pull foot-bar forces resulted in a reduction of 21% and 16% in mean paddle-stroke force and mean kayak speed, respectively. Thus, the contribution of foot-bar force from lower-limb action significantly contributes to kayakers’ paddling performance.

This study incorporated variations in speed and the horizontal resistance acting upon elite female skiers during double poling (DP) on a treadmill and specifically analyzed biomechanical adaptations to these variations. Whole body kinematics and pole force data were recorded and used to calculate the moment of force acting on the shoulder and elbow joints. Data were obtained with a 3D optoelectronic system using reflective markers at given anatomical landmarks. Forces along the long axis of the right pole were measured with a piezoelectric force transducer. Surface electrodes were used to record EMG activity in the rectus femoris, rectus abdominis, latissimus dorsi and triceps brachii muscles. In a first set of recordings, the participants double poled with zero elevation at five different speeds from 8 to 17 km h⁻¹. In a second set of recordings, horizontal resistance was added by weights (0.4–1.9 kg) attached to a pulley system pulling the skier posteriorly during DP at 14 km h⁻¹. Results showed increasing relative duration of the thrust phase with increasing resistance, but not with speed. Significant kinematic differences occurred with increase in both speed and resistance. The mean (±SD) horizontal force components ranged between 1.7 (±1.3) and 2.8 (±1.1) percent (%) bodyweight (BW) in the speed adaptation and 3.1 (±0.6) and 4.0 (±1.3) % BW in the adaptation to horizontal resistance. Peak muscle activity showed a central to peripheral (proximo-distal) activation sequence. The temporal cycle phase pattern in the adaptation to speed and horizontal resistance differed.

Background: Valid and reliable field tests for measuring physical fitness and different health parameters is an important matter for evaluating effects of exercise interventions.

Purpose: The aim was to study different test parameters such as aerobic capacity, strength, perceived health and life style habits, such as physical activity, in a physical activity intervention for elderly people.

Method: 117 old-age pensioners (99 women and 18 men). Their mean age (yrs) and BMI (kg/m² ) was 74 and 26 for the women and 73 and 25 for the men, respectively. Different aerobic, strength and balance tests were measured. Guided physical activity (nordic walking, strength training, aqua gymnastics), were given 45-60 min, 2 times/week for 8-12 weeks. Perceived exertion ratings during the exercises were moderate and/or strong.

Results: Significant changes (p< 0,05) were seen between pre- and post tests regarding all physical tests except the balance test for men. Even the perceived physical and mental health significantly improved. The mean values for questions concerning self reported inactive/active life style, including sedentary time, were changed to a more active life style.

Conclusion: 8-12 weeks of guided physical activity can improve several physiological parameters which are positively correlated to decreased risk of numerous diseases. More research is needed to develop reliable and valid field tests for physical capacity and different health parameters.

This study evaluated the Moxus metabolic system with the Douglas bag method (DBM) as criterion. Reliability and validity were investigated in a wide range of ventilation and oxygen uptake and two sensors for determining ventilation were included. Thirteen well-trained athletes participated in one pre-test and four tests for data collection, exercising on a cycle ergometer at five submaximal powers (50-263 W) and at [Formula: see text]. Gas exchange variables were measured simultaneously using a serial setup with data collected on different days in an order randomized between Moxus with pneumotachometer (MP) and turbine flowmeter (MT) sensors for ventilation. Reliability with both sensors was comparable to the DBM. Average CV (%) of all exercise intensities were with MP: 3.0 ± 1.3 for VO(2), 3.8 ± 1.5 for VCO(2), 3.1 ± 1.2 for the respiratory exchange ratio (RER) and 4.2 ± 0.8 for V (E). The corresponding values with MT were: 2.7 ± 0.3 for VO(2), 4.7 ± 0.4 for VCO(2), 3.3 ± 0.9 for RER and 4.8 ± 1.4 for V (E). Validity was acceptable except for small differences related to the determination of ventilation. The relative differences in relation to DBM at the powers including [Formula: see text] were similar for both sensors with the ranges being: +4 to -2 % for V (E), +5 to -3 % for VO(2) and +5 to -4 % for VCO(2) while RER did not differ at any power. The Moxus metabolic system shows high and adequate reliability and reasonable validity over a wide measurement range. At a few exercise levels, V (E) differed slightly from DBM, resulting in concomitant changes in VO(2) and VCO(2).

In para-kayak, athletes with unilateral above knee amputation (AK) and athletes with below knee amputation (BK) compete in the same class. This has been questioned since previous research have shown that the legs are important for paddling performance. The purpose was therefore to examine differences in kinematic and kinetic performance variables between AK and BK para-kayak athletes and the amputated (A) and non-amputated (NA) sides. Eleven AK and six BK athletes on international level participated. 3D kinematic and kinetic data were collected for the body, seat, footrest and paddle during kayak ergometer paddling. There were no significant differences between the groups in main performance variables such as power output or paddle force. Differences between the groups were only seen in the hip joint in flexion range of motion, flexion and extension angular velocity and flexion moment where BK demonstrated larger values. The NA side demonstrated greater values compared to the A side in posterior force at the seat and in hip flexion moment. As there were no significant differences between the groups in the majority of the examined key performance variables, the results suggest that athletes with unilateral AK and BK amputation may be able to compete in the same class.

Gymnastik – och idrottshögskolan, GIH, har en lång tradition av utbildning inom skidåkning. Redan 1924 genomfördes den första fjällfärden för civila studenter i Jämtland och sedan 1926 har obligatorisk utbildning i turteknik, förlagd till fjällterräng, genomförts (Schantz & Halldén, 1988). Utförsåkning och längdåkning har också länge funnits med som inslag i vinterutbildningen. För närvarande har samtliga program vid GIH (lärarprogrammet, tränarprogrammet och hälsopedagogprogrammet) en obligatorisk vinterutbildning i fjällmiljö, omfattande omkring tre högskolepoäng (cirka två veckors heltidsstudier).

Under senare år har en ökande andel av de antagna studenterna uppvisat brister vad gäller grundläggande skidfärdighet, vilket försvårat möjligheterna till breddning och fördjupning, såväl teoretiskt som praktiskt, under vinterutbildningen. De stora skillnaderna i färdighet hos studenterna innebär, förutom svårigheterna att tekniskt och didaktiskt arbeta med olika aspekter av skidåkning med heterogena grupper under en så begränsad tid, även att säkerheten under turåkningsmomentet får större fokus än vad som tidigare varit fallet. Den bristande skidåkningsfärdigheten hos vissa studenter kan bland annat få till följd att de får svårt att genomföra turåkningen. Den vanligtvis otillräckliga snötillgången i Mellansverige gör att träning på "hemmaplan" blir svår att genomföra.

I syfte att söka komma till rätta med denna problematik genomfördes ett delprojekt inom ramen för det så kallade "GIH 2008-projektet". Studenter som själva ansåg sig ha en bristande skidteknik, eller betraktade sig som nybörjare i skidåkning, erbjöds delta i projektet. Utöver möjligheten att stödja studenter som saknade eller hade liten tidigare erfarenhet av skidåkning, fanns här möjlighet att prova olika metodiker för didaktiska studier.

Denna åtgärd från GIH:s sida att bistå studenter som av geografiska, klimatologiska eller av andra orsaker inte haft möjlighet att tidigare skaffa sig skiderfarenhet kommer sannolikt att bli än mer betydelsefull i framtiden.

Nedan presenteras data för stakmomentet och diagonalåkningen i projektet. Ett antal utrustningar, bestående av skidskor, stavar och rullskidor införskaffades och studenterna fick en möjlighet att under några veckor träna rullskidåkning

Såväl kvalitativa som kvantitativa metoder användes för utvärdering av träningsprocesser. Denna utvärdering baserades på videofilmning och datorbaserad videoanalys.

Purpose:

Cardiac repolarization is a complex phenomenon that depends on heart rate (HR), autonomic nervous system (ANS) activity, age, gender and diseases/pathological conditions etc. Cardiovascular events in LQT1 mutation carriers are also typically related to age, gender, and QT interval, and are triggered by physical exercise. We studied the repolarization response to heavy exercise in healthy subjects.

Method:

Vectorcardiography (VCG) was recorded with the Coronet II system (Ortivus AB, Danderyd, Sweden) using the Frank orthogonal lead system (X, Y and Z) at supine rest before and after a maximal cycle ergometer test in 42 healthy subjects. They were of different age and gender, 21 old (64-79 years) and 21 young (20-32 years), 23 were women and 19 men. Maximum T-vector amplitude and direction were assessed as well as T-area, QTc-interval and other VCG parameters.

Summary:

At baseline most parameters differed between old and young subjects, but only QRS-duration, QRS-area and T-amplitude between women and men. Younger subjects had lower HR (59 vs 72 bpm; p<0.01), higher T-amplitude (530 vs 395 μV; p<0.01), larger T-area (73 vs 48 μVs; p<0.001), shorter QTc (417 vs 430 ms; p<0.01) and a narrower QT-angle (25 vs 59°; p<0.01).

The response to strenuous exercise was much more pronounced in the younger subjects with an increase in resting HR by 35 bpm compared with 17 bpm for the old subjects (p<0.001). This was accompanied by a more pronounced decrease in T-amplitude (-138 vs -27 μV; p<0.01) and T-area (-20 vs -7 μVs; p<0.01) but a larger prolongation of QTc (54 vs 10 ms; p<0.001).

Conclusion:

Young people seem to have a more active ANS, which results in a more pronounced repolarization response to heavy exercise. This might explain why patients with LQT1 more likely suffer from malignant arrhythmias at ages below 40 years.