Background: Women exercises more now than before, and many of them become pregnant. Exercise during pregnancy has many health benefits. Most advice about exercise during pregnancy is about exercise at a moderate intensity and prevention of pregnancy complications. Some women exercise more than these recommendations. There are advice and recommendations for elite athletes and research on high intensity exercise during pregnancy. Although it is unclear if these advice reaches pregnant women who exercises at a high intensity level.

Objective: To examine if the amount of exercise changed during pregnancy for healthy women who exercised at a high intensity level, how they had perceived the information about exercise during pregnancy they had received and where they got the information from.

Participants: Eighteen women (23–37 years) participated in the study. Criteria for inclusion were first time pregnancy, pregnant in the third trimester up until four weeks postpartum, pregnancy without complications and exercise at a high intensity at least three times a week during at least one year before and up until the pregnancy, either cardio, strength or both.

Method: The participants answered an online survey with 23 questions. The questions were about amount of exercise during pregnancy and the information about exercise the women had received during pregnancy.

Results: Most of the women decreased their amount of exercise during pregnancy and many of the women lacked adequate information to be able to exercise at desired level. Information about exercise came mainly from midwifes.

Conclusion: The amount of exercise in healthy exercising pregnant women have decreased during pregnancy at the same time as the women lacked adequate information about exercise. The women received information about exercise mainly from midwifes. It cannot be said if the lack of information has affected the amount of exercise but that would be interesting to investigate further in future studies. Continued research about high intensity exercise during pregnancy is needed to be able to give adequate information to pregnant women who exercises at a high intensity.

Introduction: Acute injuries are generally classified as more severe than overuse injuries due to the fact that they often lead to longer time away from sport. This type of classification of severity in research is not deemed appropriate since it often excludes people suffering from overuse injuries. People with overuse injuries usually stay in their sport but participates with pain, reduced function and performance.

Purpose: The purpose of this study was to examine significant differences between adherence to rehabilitation, cognitive appraisal and perceived pain depending on if a sport injury has occurred acute or due to overuse.  

Participants: 51 participants answered the questionnaire and 39 (14 women and 25 men) of these were included in the study. The participants were between 16 and 35 years old, suffered from a sport injury and had a rehabilitation program to treat their injury. Based on the diagnosis and description of the injury the participants were separated into two groups, either acute injury or overuse injury.

Method: A questionnaire including two validated questionnaires, the Rehabilitation Adherence Questionnaire and Cognitive Appraisal Health Scale and an estimation of highest experienced pain were distributed among different sport teams and social media. To investigate if there were any significant differences between the two groups on the examined variables several t-tests and one ANOVA was completed.

Results: No significant differences were found between the two groups on any of the examined variables. The category threat on the Cognitive Appraisal Health Scale were close to significance (p=0,071) and suggests that people who suffer from an acute injury found their injury to be more threatful.

Conclusion: If a sport injury has occurred acute or because of overuse doesn't seem to be a singular determinant factor that affects adherence to rehabilitation, cognitive appraisal or perceived pain

Background: One of the primary functions of the human body is to be physically active and this is essential throughout life. Adults over 18 years of age are recommended to achieve at least 150 minutes of physical activity per week with moderate intensity spread throughout the week. Physical activity reduces the risk of premature death and cardiovascular diseases. Health-inspiring apps can improve lifestyle habits such as diet and physical activity and thus prevent diseases. Social media is a collective name for communication platforms. A connection between the use of social media and a deteriorated self-image and body image has been found.  

Purpose: The purpose of the study was to give an insight into how physical activity in adult women in the age group 18-60 years is influenced by the use of social media and health-inspired apps, and how social media affects self-image and body image in younger and older women.

Participants: The participants were 165 women in the ages 18 to 60 years. The younger age group (18-30 years) included 114 participants. There were 19 participants in the age group 31-40 years and 32 participants in the age group 41-60 years.

Method: A digitized questionnaire was designed to answer questions about background information, use of social media, physical activity, body image and self-image.

Result: The study's results show that 95% of the women were physically active and 33% of these were active 4-6 hours per week. The study has shown little awareness regarding how social media can be applied to physical activity in women 18-60 years. Younger women use social media to a greater extent and experienced poorer body image and self-image compared to older women

Conclusion: The study has answered the purpose that the use of social media and apps promote physical activity in women and that there is a difference in the use of social media, comparison and self-image between the age group 18-30 and 31-60.

Background: Endurance athletes face an every-day challenge to balance high training load with sufficient rest and recovery. Variables such as Heart Rate Variability (HRV), sleep and psychological factors has proved to be important in order to detect overtraining. However, there are few studies on how these variables together can be used to monitor the status of endurance athletes. Purpose: The current study aimed to investigate the effect of one week's planned overtraining on HRV, perceived well-being and sleep duration in endurance athletes. Participants and method: Six endurance athletes, five men and one women (age 31.3±5.3, weight 69.2±7.6, VO_2max ml/kg/min 61.34±5.53, training hours 6.54 h/week), runners (n=5) and cross-country skier (n=1) participated in the five-week long study. The study consisted of four weeks of normal training load and one week of increased training load (30%). A four-minute orthostatic test was used to measure HRV analysed by the time domain RMSSD. Profile of Mood States (POMS), including Total Mood Disturbance (TMD) and Energy Index (EI) was used to monitor perceived well-being. Sleep duration was measured using Polar Vantage V. Result: No significant difference was found in HRV at rest (rHRV) or standing (sHRV), TMD or EI after the overreaching week (rHRVpre vs rHRVpost p=0.1976; sHRVpre vs sHRVpost p=0.1627, TMDpre vs TMDpost p=0.0938; EIpre vs EIpost p=0.0625). There was no significant correlation between rHRV, sHRV, TMD and EI. Statistical analysis of sleep duration could not be performed due to insufficient collected data. Conclusion: No significant changes in HRV or POMS could be found after one week of increased training load. Individual variables in POMS showed a tendency for OR, which highlights the importance of including psychological factors and not individually monitor OR based on HRV.

Introduction: Physical literacy is a multidimensional construct which, besides movement competence, also includes cognitive, emotional and social aspects. Physical literacy has been described as the key to an active life. However, there is limited empirical evidence related to physical literacy. One reason for this may be that it is assumed to be difficult to assess because of its multidimensional complexity. The purpose of this study was to explore if the physical activity levels among children in elementary school grade four differed between groups with different degrees of motor competence and self-assessed physical literacy. A secondary purpose was to compare girls and boys motor competence and self-assessed physical literacy. Method: The sample consisted of 60 healthy children of age 10–11 (M = 10.9, SD = 0.3). The tools of measurement consisted of pedometers (Denver BFH-15) for physical activity levels as well as modified versions of the test protocols PLAY Fun for motor competence and PLAY Self for self-assessed physical literacy. A Chi-Square test was used to sort participants into groups with combinations of high or low levels of motor competence and self-assessed physical literacy. Results: In this study there was no significant difference in physical activity levels between groups (p = 0.56). Furthermore, a larger share of boys than girls had developed entry level competency in certain skills (Overhand throw, Kick ball and Drop to the ground and get back up). There was, however, no significant difference between girls and boys regarding self-assessed physical literacy. Conclusion: In the present study we propose that with a larger sample and more representative measure of activity levels, this kind of research can generate valuable knowledge about physical literacy.

Purpose: Investigate if one week planned overtraining affects resting heart rate variability (HRV), and if changes in resting HRV, heart rate and lactate production at submaximal and maximal work on treadmill correlates.

Method: Six endurance athletes (men n=6, woman n=1, age 31± 5, weight 69 ± 8, VO2max ml/kg/min 61 ± 6) performed one week planned overtraining. Lactate levels at a standardized treadmill running test, VO2max and HRV during awakening were measured before and after this period to compare the changes.

Results: No indication of significant differences in HRV rest (p >0.05) was found after one week planned overtraining. A significant correlation was seen between changes in peak lactate and HR during threshold test, and also between changes in lactate production during threshold test and running distance.

Conclusion: Possibly the period of overtraining would have needed to last for longer than one week, or be more intense, to find significant changes in the markers HRV, HR and lactate.

Introduction

Groin muscle strain is the second most common muscle strain among soccerplayers and represent up to 28% of all soccer related injuries annually. There are multiple risk factors contributing to this type of injury, the strength ratio of hip adductors-abductors being one of them. Furthermore, pain has shown to decrease muscle strength. The purpose of this study was to examine the correlation between the strength ratio of hip adductors-abductors and perceived pain.

Method

One male subelite soccer team (n= 14) from Umeå participated inthis study.Thetwo tests that were conducted was the hand-held dynamometer and the Five-Second Squeeze Test (5SST). The hand-held dynamometer is a valid and reliable device used to examine the strength ratio of hip adductors-abductors and the 5SST is a valid measurement of hip and groin function insoccer players.

Results

No significant correlation was found between the strength ratio of hip adductors-abductors and perceived pain in the 5SST (p<0.05) in the present study.

Conclusion

The findings in the present study showed no significant correlation between the strength ratio of hip adductors-abductors and perceived pain in the 5SST. Based on the result, 5SST cannot be used to identify the strength ratio of hip adductors-abductors in soccer players. The present study emphasis the importance of larger studies with higher number of participants in the future to analyze the correlation of strength ratio and perceived pain.

With higher age there tend to be a decrease in the autonomic regulation of the cardiovascularsystem. Exercise is hypothesized to improve autonomic function but the time and intensitynecessary for substantial improvements has not been concluded. High intensity training(HIT)training poses potential time benefits that may aid physically inactive people.

The purpose of this study was to evaluate the effects of a 6-week High intensity interval training(HIIT)-program vs a 6-week Moderate intensity exercise training (MIET)-program on autonomic function in physically in-active older adults.

Home recordings of blood pressure and heart rate variability was conducted prior to and 6-weeks in to the training period. Training was carried out in a gym setting, 2 times weekly, duringa 6-week period. Participants were randomized to either the HIIT or MIET protocol with 15 participants in the HIIT group and 15 participants in the MIET group.

There was no significant difference in Heart rate variability after a 6-week training programregardless of time and intensity of exercise. The MIET group reduced morning blood pressure parameters significantly (Mean arterial pressure mornings: 95% Confidence interval (CI)I:-5,8- -0,7, p=0,016; Morning systolic pressure: CI:-9,3- -1,3, p=0,002; Morning diastolic pressure: 95%CI:-4,2- -0,3, p=0,03), the HIIT group did not (Mean arterial pressure mornings: 95% CI: -10,3-1,8,p=0,147; Morning systolic pressure: 95% CI: -12,3-1,5, p=0,110; Morning diastolic pressure:95%CI: -9,5-2,2, p=0,196).

A 6-week training protocol is not sufficient in order to improve autonomic function in a population of older inactive adults.

Introduction: The vertical jump ability is essential for performance in many sports. The use of complex training has in previous research been shown to provide significantly improved power development. Post-Activation Potentiation (PAP) is a physical phenomenon that increases muscle tension and the force development of the working muscles which can be implemented in complex training.

The purpose of this study was to investigate whether athletes in basketball, football, handball and volleyball will have a favorable increase in Countermovement jump with arm swing (CMJa) if they perform heavier squats with a load of 50% and 80% of their estimated or measured 1 repeat maximum (RM) before CMJa.

Method: 9 men and 2 women, age 20.6±3.3 years, height 181.4±7.4 cm, 76.9±12.6 kg body mass participated in the study. All participants were active in one of the sports basket, football, handball or volleyball. The participants performed two set of squats followed by five set of two repetition CMJas with a five minutes rest in between. An infrared sensor MuscleLab was used to analyze the jump height.

Results: The result showed no significant difference between heavy squats and jump height in CMJa over time (p=0.98).

Conclusion: Squats with 50% and 80% of 1RM do not seem to improve jump height performance in CMJ on team sports players. The result in this study does not support the results in previous studies showing a positive effect of heavy squats on maximal jump height.

High Intensity Training (HIT) is a time efficient training method with positive effects on several health outcomes. Although promising, HIT has found it difficult to compare with Moderate Intensity Continuous Exercise (MICT) regarding affective responses during exercise, an important predictor to future exercise behavior. The purpose of this study was to compare the affective responses during two different forms of cycle ergometer training in sedentary older adults, and to describe affective responses over time. A secondary purpose was to evaluate the relationship between affective responses and perceived exertion. A regulated supramaximal HIT protocol (10 x 6 sec) was compared to MICT (3 x 8 min). Thirty participants (aged 69,4 ± 2,9; 15women) completed physical tests and were then randomized into six weeks of HIT or MICT (12 sessions). Affective state was measured using Feeling Scale (FS) and perceived exertion through Borg’s Rating of Perceived Exertion (RPE). There was no significant differences between groups regarding the affective responses assessed at the end of the final interval on any of the 12 sessions. The affective response during the last interval remained positive throughout the intervention (HIT: +3,0 to +3,7; MICT: +3,0 to +3,9). A weak correlation was observed between FS and Borg’s RPE for both interventions (HIT: p<.0001, rs = -.3724; MICT: p<.0001, rs = -.3697). This study highlights HIT with very short sprint intervals as a time efficient and feasible training method in sedentary older adults due to the participants’ positive affective responses. Future studies should examine the effects of this novel training method.

Background: Team sports involves high demands on the ability to change direction numerous times at high velocities during a game. Ice hockey has evolved towards more intense actions during a game with higher demands on the ability to change direction. Eccentric strength is required for an effective change of direction and science today can show that the relative eccentric strength is a factor in other types of team- sports. However, there is a lack of corresponding science in the game of ice hockey.

Purpose: The aim of this study was to examine the relationship between eccentric quadriceps and hamstring strength and the ability to change direction in ice hockey players. The hypothesis was that higher eccentric strength would correlate with faster performance times in the 505- test.

Method: Twelve adolescent men (16,6 ±0,8 years, weight 82 ± 9,3 kg , height 180,4 ± 6,2 cm) underwent an eccentric protocol for quadriceps and hamstrings in a dynamometer, 60°/s och 210°/s, and a 505- test off- ice on separate testing days to explore the relationship between the two variables.

Result: The main findings revealed significant relationships between the eccentric strength in hamstring 60°/s and performance time in the 505-test with a turn to the left. No significant relationships could be found between the other variables.

Conclusion: The results from this study revealed that eccentric strength in hamstrings may have a role in an effective change of direction. However, further studies should aim to explore the relationship between the ability to change direction on and off ice.

Positive effects from sports are achieved primarily through physical activity, but secondary effects bring health benefits such as psychosocial and personal development and less alcohol consumption. Negative effects, such as the risk of failure, injuries, eating disorders, and burnout, are also apparent. Because physical activity is increasingly conducted in an organized manner, sport's role in society has become increasingly important over the years, not only for the individual but also for public health. In this paper, we intend to describe sport's physiological and psychosocial health benefits, stemming both from physical activity and from sport participation per se. This narrative review summarizes research and presents health-related data from Swedish authorities. It is discussed that our daily lives are becoming less physically active, while organized exercise and training increases. Average energy intake is increasing, creating an energy surplus, and thus, we are seeing an increasing number of people who are overweight, which is a strong contributor to health problems. Physical activity and exercise have significant positive effects in preventing or alleviating mental illness, including depressive symptoms and anxiety- or stress-related disease. In conclusion, sports can be evolving, if personal capacities, social situation, and biological and psychological maturation are taken into account. Evidence suggests a dose-response relationship such that being active, even to a modest level, is superior to being inactive or sedentary. Recommendations for healthy sports are summarized.

Introduction: The overall aim of this doctoral thesis was to identify physiological and anthropometric variables valid for prediction of competitive performance in alpine skiing (indicated by FIS points).

Method: Paper I-III in this doctoral thesis followed an experimental, hypothesis-generating design which included both junior and senior elite alpine skiers. In all papers, physiological and anthropometric test results (X-variables) were correlated with FIS points (Y-variables) in order to investigate the predictive power of physiological and anthropometric variables for competitive performance in alpine skiing. The significance of the included test results was examined using bivariate and multivariate data analysis.

Results: The results of Paper I show that included aerobic test results, neither alone nor in combination with anthropometric variables, could predict competitive performance of junior elite alpine skiers. Principal component analysis shows that male and female junior alpine skiers could be separated based on test results but that none of the included tests were important for sport-specific performance. The best multivariate models reached R² = 0.51 to 0.86 and Q² = -0.73 to 0.18. While several significant regression models could be observed, none of these met the criteria for valid models. The lack of predictive power of observed prediction models was confirmed by cross-validation. The results of Paper II show that included physiological test results from the test battery Fysprofilen could not predict competitive performance of senior elite female alpine skiers. Principal component analysis shows that there is a high correlation between individual physiological test results and their corresponding Fysprofilen score points, indicating that they can be used interchangeably. The Mann-Whitney U test was not significant neither for SL nor for GS. This suggests that Fysprofilen score points (summarized as Fysprofilen Index) and competitive performance (indicated by FIS points) are independent. The best multivariate models for SL and GS reached R² = 0.27 to 0.43 and Q² = - 0.8 to - 0.17, indicating low predictive power for competitive performance (as confirmed by cross-validation). The results of Paper III show that included physiological test results from a novel test battery could not predict competitive performance of senior elite female alpine skiers on a group level. When data were analyzed on a group level, the best models for SL and GS reached R² = 0.39 to 0.40, Q² = 0.15 to 0.21, indicating low predictive power. In contrast, when data were analyzed on an individual level, valid models with high predictive power (R² = 0.88 to 0.99 and Q² = 0.64 to 0.96) were generated. A comparative analysis between individual multivariate models shows that the relative importance of different physiological qualities for athletic performance varies between skiers.

Conclusion: When applying tests on alpine skiers, a holistic approach should be considered. This because competitive performance in alpine skiing is the result of a number of interacting dimensions. Before applying physiological tests, the validity and reliability of the test protocols must also be determined. Administering tests that do not meet these criteria will probably waste not only important resources for clubs and ski federations but also risk misleading coaches and athletes when planning and implementing preparatory training.

Introduction: The Swedish population does not meet the recommendations for 150 minutes physical activity per week, even though the health benefits from being physically active is well known. Lack of motivation is a variable that contributes to this problem and results in insufficiently physical activity. This study aimed to explore differences in types of motivation and physical activity level, and also see if there is any differences between gender and age.

Methods: Participants (n = 251) between 18-64 years of age completed an online survey, based on Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2) and The Godin-Shephard Leisure-Time Exercise Questionnaire (GLTEQ).

Results: ANOVA showed significant differences between type of motivation and activity level. The high-active group had more motivation to physical activity than less active groups. Women had more introjected regulation than men, while men had more identified regulation than women. People between 18-24 showed significant more extrinsic regulation.

Conclusion: Based on the findings, it is difficult to define which motivation type that main contributes to physical activity, but there are indications that all types of motivation is important for being physically active. Future research could do a more extended investigation on a wider population to get a deeper insight.

Purpose To evaluate the information provided by Polar Vantage V, a new generation of heart rate monitor/watch (HRM-watch) to the user, regarding the acute:chronic load ratio (ACLR), based onthe external and internal load measures and examine the measures against psychological and physiological measures before and during a threshold test with VO2max testing.

Method A five-week prospective study with results and data collected during and after four normal training weeks and during a fifth week with a very high training load. The results from HRM-watchwere then evaluated against the results from physiological and psychological tests. Eight endurance runners were recruited.

Results Differences in ACLR against the differences in HRR show a R2 value of 0.77 (p<0.05). ACLR signicantly increased with an average of 0.33 from 0.93 to 1.26 (p=0.003, 95 % CI= 0.17 {0.49). Differences in ACLR against dierences in total mood disturbance (TMD) from POMS showin regression analyses a R2value of 0.67 (p=0.05). No significant difference was noted in neither resting HRV (p=0.3, 95% CI= -22.2 { 8.5) or standing HRV (p=0.15, 95% CI= - 4.15 { 20.8).

Conclusion Based on the result of the present study it can be concluded that training status, well-being and present mood state can be predicted fairly good with the information from the internal and external load measurements from the Polar Vantage V. However, the power of present exploratory study was low due to a low number of included participants. Future research with greater number of participants and an improved study design is needed to verify these interesting findings.

Dance requires multiple physical skills, still it is not considered a sport. Injury occurrence among dancers is high and the most common kind is overuse injuries in the lower body. High training volume in relation to inadequate rest, low energy availability and insufficient knowledge within the area of sports medicine could be predisposing factors to injuries among dancers.

To support a sustainable career for dancers the aim of this study was to examine the occurrence of, predisposing factors to, and to suggest prevention strategies to dance-related injuries. Female students within professional dance and dance pedagogy educations in Sweden were examined through a questionnaire study. The questions asked due to dance-related injuries among the students were: (1) How is the current progress of dance-related injuries, and how are the injuries divided between the lower and upper body? (2) What is the prognosis of the training volume in relation to the rest and the experienced physical condition? (3) How is the quantity of daily ingestions? (4) How is the menstrual cycle? (5) How is the perceived knowledge within the area of sports medicine?

A total amount of 148 female students from selected educations were given the opportunity to participate in this study. The responsible for the study designed questions and pilot tested them on female dancers. The questions were designed in a questionnaire on the web and emailed to selected educations.

17/148 students attended in the study and nine of them completed it. The main findings of this study were that overuse injuries (10/14 injuries), injuries in the lower body (8/14 injuries) and high training volume (more than 16 h/w) (7/13 participants) among the participants was common. No signs of low quantity of daily ingestion or menstrual dysfunction were shown among the majority of the participants. Within the area of sports medicine the majority of the participants wanted extended knowledge about injury prevention training (7/10 participants) and physiology (9/10 participants).

Suggested injury prevention strategies were that the schools should establish lessons especially for injury prevention training and implement screening-controls on the students, completed by sports medicine staff. Futureresearch is needed to clarify which sort of injury prevention training that is suitable specifically for dancers.

Background: The accumulation of myocardial triglycerides and remodeling of the left ventricle are common features in type 2 diabetes mellitus and represent potential risk factors for the development of diastolic and systolic dysfunction. A few studies have investigated the separate effects of diet and exercise training on cardiac function, but none have investigated myocardial changes in response to a combined diet and exercise intervention. This 12-week randomized study assessed the effects of a Paleolithic diet, with and without additional supervised exercise training, on cardiac fat, structure, and function.

Methods and Results: Twenty-two overweight and obese subjects with type 2 diabetes mellitus were randomized to either a Paleolithic diet and standard-care exercise recommendations ( PD ) or to a Paleolithic diet plus supervised exercise training 3 hours per week ( PD - EX ). This study includes secondary end points related to cardiac structure and function, ie, myocardial triglycerides levels, cardiac morphology, and strain were measured using cardiovascular magnetic resonance, including proton spectroscopy, at baseline and after 12 weeks. Both groups showed major favorable metabolic changes. The PD - EX group showed significant decreases in myocardial triglycerides levels (-45%, P=0.038) and left ventricle mass to end-diastolic volume ratio (-13%, P=0.008) while the left ventricle end-diastolic volume and stroke volume increased significantly (+14%, P=0.004 and +17%, P=0.008, respectively). These variables were unchanged in the PD group.

Conclusions: Exercise training plus a Paleolithic diet reduced myocardial triglycerides levels and improved left ventricle remodeling in overweight/obese subjects with type 2 diabetes mellitus.

Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01513798.

The purpose of the present study was to examine coaches’ perspective of injuries and rehabilitation within artistic gymnastics (AG). In particular, the study explored the influence of coaches’valuation of gymnasts’self-efficacy on performance, injuries and in the rehabilitation process. Further, the coaches’ role in athletes’ rehabilitation of injuries and the decision to return to sport participation after an injury was examined. Previous research has shown that the frequency of incidence of injury in AGis relatively high, however well-established rehabilitation protocols to return to sport participation within gymnastics are limited. Extensive research notes that athletes’ self-efficacy influences performance and is central in a successful process of injury rehabilitation. Previous studies have highlighted that coaches play a significant role in athletes’ rehabilitation from injury; for example, coaches offer emotional and informational support. The present study undertook semi-structured interviews withAG coaches (N=6) to collect data regarding their perspectives of the occurrence of injury, rehabilitation, gymnast’sself-efficacy as well as their role in the rehabilitation process. In general, coaches assumed that overuse injuries were most frequent inAG and marked an importance of a coaches’ ability to adapt the training to the needs/capacity of the gymnasts. Allthe coaches considered gymnastsfear and lack of confidence as risk factors for injuries. They expressed that coaches can have an impact on gymnasts’ self-efficacy. The findings in this study are discussed in relation to previous studies on injuries, rehabilitation, self-efficacy, and the coaches’ role in athletes’ rehabilitation

Recent advancements in 3D data gathering have made it possible to measure the distance to an object at different time stamps through the use of time-of-flight cameras. Therefore, the purpose of this study was to investigate the validity and reliability of a time-of-flight camera on different mechanical sprint properties of the muscle.

Fifteen male football players performed four 30m maximal sprint bouts which was simultaneously recorded with a time-of-flight camera and 1080 sprint device. By using an exponential function on the collected positional- and velocity-time data from both the devices, following variables were derived and analyzed: Maximal velocity (nmax), time constant (t), theoretical maximal force (F0), theoretical maximal velocity (V0), peak power output (Pmax), F-V mechanical profile (Sfv) and decrease in ratio of force (Drf).

The results showed strong correlation in vmax along with a fairly small standard error of estimate (SEE) (r = 0,817, SEE = 0,27 m/s), while t displayed moderate correlation and relatively high SEE (r = 0,620, SEE = 0,12 s). Furthermore, moderate mean bias (>5%) were revealed for most of the variables, except for vmax and V0. The within-sessions reliability using Intraclass correlation coefficient (ICC) and standard error of measurement (SEM) ranged from excellent to poor with Pmax displaying excellent reliability (ICC = 0,91, SEM = 72W), while vmax demonstrated moderate reliability (ICC = 0,61, SEM = 0,26 m/s) and t poor(ICC = 0,44, SEM = 0,11 s).

In conclusion, these findings showed that in its current state, the time-of-flight camera is not a reliable or valid device in estimating different mechanical properties of the muscle during sprint running using Samozino et al’s computations. Further development is needed.

The world’s population is rapidly becoming older and many older adults suffer fromsarcopenia; low muscle mass and function, which may lead to falls, fractures and death. Although it is widely known that resistance training (RT) prevent loss of muscle mass and function, the prevalence of RT among older adults is low. The aim of this feasibility study was therefore to explore the effectiveness and describe user experience of a digital RT program in 31 men and women 71 years of age with low muscle mass. The outcome measures were changes in lean mass and physical function. Semi structured one-to-one interviews with eight participants were also made to get a greater view of participants experience of the digital training. The material was transcribed and analysed with qualitative content analysis. Significant improvements in lean body mass was observed (p=0.041), as well as chair stands and grip strength (p<0.05 for both) for the functional measures. Two themes emerged fromthe content analysis; “A feeling of a physical and mental change” and “Importance of being confirmed but at the same time be self-dependent“. The themes captured the participantsexperience and feasibility of the intervention, where a sense of how the body was changing and the importance of well-being were described. These findings indicate that this digital RTprogram was effective in increasing muscle mass and function. Combined with participants experiences, this intervention may lead to better compliance to RT. More research is needed to asses changes in a long-term perspective.