Gymnastik- och idrottshögskolan, GIH

The study aimed to identify a small set of fitness tests that could effectively predict performance in simulated firefighting tasks. Thirty-six (25 male and 11 female) firefighters participated in the study. Strength was evaluated with grip strength, barbell bench rows, and elevated trap bar deadlifts. Work capacity was assessed using a 3-minute pyramid test, executed with and without firefighting equipment. Firefighting performance was evaluated using a simulated work task course comprising stair climbing, hose pull, victim rescue, and equipment carry. We used backward linear regressions to derive models incorporating fitness test results, demographic variables, and oxygen uptake measures as predictors. Statistical significance was set to p < 0.05. The pyramid test without equipment accounted for 59% of the variance in task performance. When body mass and height were included, the model's predictive power increased to 71%. A final model, integrating the pyramid test, body mass, and absolute maximal oxygen uptake capacity (V̇o2max), explained 81% of performance variation. Our findings indicate that V̇o2max is the key factor in firefighter task performance, explaining 69% of the variance. The pyramid test, which estimates V̇o2max and predicted 59% of performance, is simple, time efficient, and can be conducted at stations to assess physical ability and work capacity. Incorporating the pyramid test into regular assessments can help firefighters focus on improving their work capacity, which is essential for achieving better performance.

Introduction: Information on the long-term maintenance of short-term exercise fitness gains measured by field-based tests is scarce in older adults. This study aimed to investigate short- and long-term changes in various physical fitness parameters after an 8-week exercise program.

Methods: In this longitudinal study, a total of 265 participants (62% women; mean age 71.4 ± 4.7 years) completed a field-based test battery of 12 fitness tests (22 parameters) at 2 pre-tests and 1 post-test following an 8-week exercise program (2 sessions/week, combining aerobic and strength activities) in 2 consecutive years. The tests assessed muscle endurance, muscle strength, cardiorespiratory fitness, and motor fitness.

Results: Significant short-term improvements were observed, e.g., in isometric trunk flexion and extension endurance (21–37%) for both sexes in both years. Lower-body muscular endurance improved in the first year (9–12%) for both sexes, while cardiorespiratory fitness (6-min walk test) improved only for men in both years (3%). No changes were seen in submaximal cycle test heart rates or any balance tests in any year. Most fitness parameters did not significantly decrease during the 9-month inter-intervention period, with a few exceptions in trunk strength and walking distance.

Conclusions: This study demonstrates physical fitness improvements in older adults following short-term exercise interventions and that some of these improvements were maintained long term, whereas a few of these physical fitness test improvements decreased significantly over 9 months in older adults.

UNLABELLED: The interest in using new technologies to obtain recordings of on-water kinetic variables for assessing the performance of elite sprint kayakers has increased over the last decades but systematic approaches are warranted to ensure the validity and reliability of these measures. This study has an innovative approach, and the aim was to develop a new versatile jig including reference force sensors for both the calibration and validation of mutual static and dynamic stroke forces as measured with instrumented paddles at the high force levels used in elite sprint kayaking.

METHODS: A jig was constructed using a modified gym weight stack and a frame consisting of aluminum profiles permitting a fastening of custom-made kayak paddle shaft and blade support devices with certified force transducers combined with a data acquisition system to record blade and hand forces during static (constant load) and dynamic conditions (by paddle stroke simulation). A linear motion path incorporating a ball-bearing equipped carriage with sensors for the measurement of vertical distance and horizontal displacement was attached to the frame for recordings of various position measures on the paddle. The jig design with all components is extensively described to permit replication. The procedures for assessing the accuracy of the jig force instrumentation are reported, and with one brand of instrumented paddle used as an example, methods are described for force calibration and validation during static and dynamic conditions.

RESULTS: The results illustrate that the measured force with the jig instrumentation was similar to the applied force, calculated from the applied accurate mass (within a -1.4 to 1.8% difference) and similar to the force as calculated from the applied mass with the weight stack (within a -0.57 to 1.16% difference). The jig was suitable for the calibration and validation of forces in a range relevant for elite sprint kayaking under both static and dynamic conditions. During static conditions with a force direction equal to the calibration conditions and a force range from 98 to 590 N, all values for the instrumented paddle were within a -3.4 to 3.0% difference from the jig sensor values and 28 of 36 values were within ±2%. During dynamic conditions with paddle stroke simulations at 60 and 100 strokes/min and a target peak force of 400 N, the common force variables as measured by the instrumented paddle were not significantly different from the same measures by the jig (values at 100 strokes/min: peak force; 406.9 ± 18.4 vs. 401.9 ± 17.2 N, mean force; 212.8 ± 15.4 vs. 212.0 ± 14.4 N, time to peak force; 0.17 ± 0.02 vs. 0.18 ± 0.02 s, force impulse; 90.8 ± 11.2 vs. 90.5 ± 10.8 Ns, impulse duration; 0.43 ± 0.03 vs. 0.43 ± 0.03 s).

CONCLUSION: A novel jig with several new functions is presented that enables the calibration and validation of force measurements with instrumented paddles by providing standardized conditions for calibration and force validation during both static and dynamic conditions in a force range relevant to elite sprint kayaking.

INTRODUCTION: Physical fitness is strongly associated with daily physical function, health, and longevity in older adults. Field-based tests may provide a reasonable alternative compared to advanced laboratory testing. Separating postexercise test scores from reactivity measurements requires sufficient test-retest reliability. Postexercise test scores with reliability analyses of field-based fitness tests in older adults are lacking. The present study aimed to examine the test-retest reliability of some novel easily accommodated fitness test measurements and compare pretest scores with postexercise results in these tests along with other field-based fitness tests in older adults.

METHODS: Totally 1,407 community-dwelling older adults (69% female), x̄ = 71.5 ± 5.0 (65-84 years), performed twelve field-based fitness tests at pretest 1, pretest 2 and a posttest after an 8-week exercise period (twice weekly 1 h of combined strength and aerobic training). T tests, intra-class correlation, limits of agreement, standard error of measurement, and coefficient of variance were performed between pre-1 and pre-2 tests, and repeated measures ANOVA and partial eta squared effect size for postexercise differences for men and women in 5-year age groups ranging from 65 to 84 years.

RESULTS: Between pre-1 and pre-2 tests a significant difference was noted in some of the novel fitness test measurements but generally not, e.g., in isometric trunk flexion and step-up height on either leg among all sex and age groups. In most of these novel fitness test measurements, no significant differences occurred between the two pretests. Examples of results from the pre-2 test to the posttest were isometric trunk flexion 45° endurance and isometric trunk extension endurance improved significantly for both sexes in age groups 65-74 years. Women, but not men, improved the maximal step-up height for both legs in most age groups. The speed in the 50 sit-to-stand improved significantly for most age groups in both sexes. Six-min walk distance improved significantly for most age groups in women but among men only in 65-69 years. In the timed-up-and-go test, significant improvements were seen for all age groups in women and in men 70-79 years. No postexercise improvements were generally observed for grip strength or balance.

CONCLUSIONS: In most of the novel fitness test measures, no significant difference was noted between the two pretests in the assessed sex and age groups. Results after the 8-week exercise period varied between sex and age groups, with significant improvements in several of the twelve studied fitness tests. These findings may be valuable for future projects utilizing easily accommodated physical fitness tests in older adults.

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.

BACKGROUND: Reliable physical activity measurements in community-dwelling older adults are important to determine effects of targeted health promotion interventions. Many exercise interventions aim to improve time spent sedentary (SED), in light-intensity-physical-activity (LPA) and moderate-to-vigorous-intensity-physical-activity (MVPA), since these parameters have independently proposed associations with health and longevity. However, many previous studies rely on self-reports which have lower validity compared to accelerometer measured physical activity patterns. In addition, separating intervention-effects from reactivity measurements requires sufficient test-retest reliability for accelerometer assessments, which is lacking in older adults.

OBJECTIVES: The study objective was to investigate the reliability of sensor-based PA-patterns in community-dwelling older adults. Furthermore, to investigate change over time of physical activity patterns and examine any compensatory-effect from the eight-week supervised exercise-intervention.

METHODS: An exercise-group (n = 78, age-range:65-91yrs) performed two 1h-exercise sessions/week during eight-weeks. PA-pattern was assessed (using hip-worn accelerometers), twice before and once during the last-week of the intervention. A control-group (n = 43, age-range:65-88yrs) performed one pre-test and the end-test with no exercise-intervention. A dependent-t-test, mean-difference (95%-CI), limits-of-agreement and intraclass-correlation-coefficient-ICC were used between the two pre-tests. Repeated-measures-ANOVA were used to analyze any intervention-effects.

RESULTS: The exercise-groups´ two pre-tests showed generally no systematic change in any PA- or SED-parameter (ICC ranged 0.75-0.90). Compared to the control group, the exercise intervention significantly (time x group-interaction, p<0.05) increased total-PA-cpm (exercise-group/control-group +17%/+7%) and MVPA-min/week (+41/-2min) and decreased %-of-wear-time for SED-total (-4.7%/-2.7%) and SED-bouts (-5.7%/-1.8%), and SED-bouts min/d (-46/-16min). At baseline level, no significant differences were found between the two groups for any parameter.

CONCLUSIONS: The current study presents a good test-retest-reliability of sensor-based-one-week-assessed-PA-pattern in older-adults. Participating in an 8-week supervised exercise intervention improved some physical activity and sedentary parameters compared to the control group. No compensatory-effect was noted in the intervention-group i.e., no decrease in any PA-parameter or increase in SED at End-test (in %-of-wear-time, min/day or total-PA).

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 purpose was to study if young football players can develop theirnonvisual sensory performance, here defined as control of the ball withoutvisual feedback. In total 20 elite male football players participated in thestudy. Their mean age (±SD) was 12.1 (±0.5) years. The participants weredivided into an intervention group (n=12) and a control group (n=8). Theselection of players was based on performance in the non-visual slalom pretest. The study followed a pre- post-test design in which the interventiongroup practiced ball control without visual feedback (nonvisual sensorytraining) three times 30 minutes per week over four weeks as part of theirnormal training. The control group exercised conventional football trainingwith full vision for the same amount of time. The pre- and post-test consistedof two sub-tests performed with and without visual control: 1) a stationaryball control test and 2) a slalom course ball drive test. The results show asignificant improvement in the intervention group in both the stationary ballcontrol test (p<0.001 and Effect Size (ES)=1.59) and in the slalom balldrive test (p<0.004 and ES=1.09). The control group showed no significantchanges in performance between the pre- and post-test.

Conclusion. Nonvisual sensory skill can be significantly improved in12 training sessions of 30 minutes each in young elite male football players.

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 &lt; 0.001 and P &lt; 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 &lt; 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.