Participation and performance characteristics in half-marathon run: a brief narrative review.

Half-marathon (HM) is a running sport of increasing popularity in both sexes and in all age groups worldwide during the last years. Many studies have examined several aspects of HM, such as performance and participation trends, sex and age differences, physiological correlates, and training; however, no comprehensive review has ever been contacted to summarize the recently accumulated knowledge. Therefore, the aim of the present study was to review all previous research in this sport, focusing on participation and performance aspects. It was shown that HM runners had similar anthropometric and physiological characteristics as full-marathon runners which should be attributed to the affinity of these two races in terms of metabolic demands. Performance in HM was related with superior scores in aerobic capacity (maximal oxygen uptake, anaerobic threshold and running economy) and training characteristics (sport experience, weekly distance, training speed, frequency of sessions and long single endurance run distance), and lower scores in adiposity-related scores (e.g. body mass, body mass index, body fat percentage and skinfold thickness). Considering the popularity of HM race and the lack of many original studies (compared to FM race), this is an exciting field for scientific research with a large potential for practical applications, since the majority of HM runners are amateur runners in need of sex-, age- and performance-tailored exercise prescription.

Shoulder Internal Rotator Strength as Risk Factor for Shoulder Pain in Volleyball Players.

The aim of this study was to identify the intrinsic factors that could increase risk of shoulder pain in adolescent volleyball players. Twenty-eight young male volleyball players (between 14 and 18 years old) participated in this study. Athletes were submitted to: isokinetic muscle strength assessment of shoulder rotator muscles, ball service speed assessment, anterior and posterior drawer test, apprehension test, groove sign and scapular dyskinesia test. Athletes were followed for 16 weeks to monitor the presence of shoulder pain. All athletes were submitted to the same training protocol. During the 16 weeks, 28.5% of the athletes (n=8) experienced shoulder pain in the dominant limb higher than 3 according to Numerical Rating Scale criteria; 71.5% of the athletes (n=20) did not experience pain, or pain equal or lower than 3. The main result of our study was that the odds of feeling pain higher than 3 was significantly higher among players who presented higher values for internal rotation peak torque (OR=1.113, CI 95%=1.006 to 1.232 and p=0.038). The odds of feeling pain increased by 11% for every N·m of the internal rotator muscles. Pre-season isokinetic rotator strength assessments can help identify adolescent volleyball players at increased risk of a shoulder injury.

Interval Training with Different Intensities in Overweight/Obese Adolescent Females.

To compare the effects of 12 weeks of high-intensity interval training (HIIT) versus moderate-intensity interval training (MIIT) on hematological and inflammatory markers in youth females, 38 overweight/obese females (16.4±1.0 yrs.) were randomly assigned to HIIT (2×6-8 repetitions of 30 s at 100-110% maximal aerobic speed (MAS), with 30 s active recovery between repetitions at 50% MAS; n=13), MIIT (2×6-8 repetitions of 30 s at 70-80% MAS, with 30 s active recovery between repetitions at 50% MAS; n=13), and a control group (CG, no intervention; n=12). Body composition, blood pressure, maximal heart rate, hematological and inflammatory markers (C-reactive protein [CRP], and erythrocyte sedimentation rate [ESR]) markers were assessed in all groups before and following the training program. Results revealed a significant (P<0.05) interaction effect for body composition, systolic blood pressure (SBP), MAS, maximal heart rate, and CRP. Within-group analyses for the HIIT and MIIT groups showed significant improvements in body mass (P=0.009 and P=0.025, respectively), BMI Z-score (P=0.011 and P=0.028, respectively), and MAS (P<0.001 and P=0.011, respectively). The HIIT program showed a significant decrease in body fat (P=0.002), waist circumference (P=0.002), maximal heart rate (P=0.003), SBP (P=0.001), and plasma CRP (P=0.004). In both groups, no significant changes were observed in ESR and hematological markers after intervention. No variable changed in CG. HIIT was the effective method to manage cardiometabolic health and inflammatory disorders in obese youth.

Isokinetic Muscular Strength and Aerobic Physical Fitness in Recreational Long-Distance Runners: A Cross-Sectional Study.

ABSTRACT: Andrade, MS, Silva, WA, de Lira, CAB, Mascarin, NC, Vancini, RL, Nikolaidis, PT, and Knechtle, B. Isokinetic muscular strength and aerobic physical fitness in recreational long-distance runners: A cross-sectional study. J Strength Cond Res 36(3): e73-e80, 2022-Muscular strength, bilateral asymmetry, and imbalance between antagonist muscles have been considered as risk factors for knee injuries. Moreover, muscular strength has also been associated with aerobic performance. The aim of the study was to investigate bilateral muscular symmetry and muscular strength balance assessed by isokinetic dynamometry in recreational long-distance runners and to verify whether knee muscular strength would be associated with maximal oxygen uptake (V̇o2max), anaerobic threshold (AT), and running economy (RE). Thirty-nine runners (male [n = 24]: age, 30 ± 8 years; height, 176.0 ± 7.3 cm; body mass, 70.3 ± 8.0 kg; race pace below 4:30 min·km-1 and female [n = 15]: age, 31 ± 7 years; height, 163.0 ± 3.8 cm; body mass, 55.9 ± 4.7 kg; race pace below 5:00 min·km-1) participated in this study. Comparing the conventional knee balance ratio with the literature recommendation (60%), male runners presented significantly lower values for the nondominant side (55.5 ± 7.3%; p = 0.001; d = 0.85; confidence interval [CI] = 0.47 to 1.20) but not for the dominant side (58.1 ± 6.8%; p = 0.208; d = 0.37; CI = -0.12 to 0.86). Female runners presented lower values for both sides (52.1 ± 7.1%; p = 0.001; d = 1.55; CI = 0.86 to 2.20 and 50.7 ± 8.0%; p = 0.001; d = 1.62; CI = 0.90 to 2.30 for dominant and nondominant sides, respectively). Female and male runners presented nonfunctional ratio imbalance and asymmetry of bilateral strength. Strength outcomes were not associated with V̇o2max, AT, or RE. In conclusion, recreational runners were characterized by an imbalance in muscular strength between knee flexor and extensor muscles, which was more obvious in female runners, and by symmetrical thigh muscle strength values. Moreover, muscular isokinetic knee flexor and extensor muscle strength was not associated with aerobic fitness parameters.

Return to classes impact on mental health of university students during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic and the necessary social isolation and distancing measures - that were adopted to prevent spreading the virus, including the suspension of university classes - negatively impacted the mental health of young adults. The aim of the current study was to investigate whether returning to online classes, even not presential, during the social isolation of the COVID-19 pandemic, affected the mental health of university students. METHODS: Forty students (10 men and 30 women) (age, 22.3 ± 3.8 years; body mass, 62.5 ± 17.8 kg; height, 165.6 ± 8.7 cm) from undergraduate health courses participated in the study. The students answered a self-administered questionnaire designed to gather personal and quarantine information as well as information about the frequency of depression (PHQ-9) and anxiety (GAD-7) symptoms. The questionnaire was answered before and after the return to online classes. RESULTS: There was a significantly lower frequency of depression symptoms after the return to online classes (Z = -2.27; p = 0.02). However, there was no difference in anxiety symptoms before and after returning to online classes (Z = -0.51; p = 0.61). CONCLUSIONS: Return to online classes positively impacted the mental health (decrease of frequency of depression symptoms) of university students. Future studies are needed to observe whether the changes observed after returning to school are maintained over time.

Trends in Participation, Sex Differences and Age of Peak Performance in Time-Limited Ultramarathon Events: A Secular Analysis.

Background and Objectives: Increases in the number of participants in time-limited ultra-marathons have been reported. However, no information is available regarding the trends in participation, performance and age in 12 h and 24 h time-limited events. The aim of the study was to describe the trends in runners' participation, performance and age in 12 h and 24 h ultra-marathons for both sexes and to identify the age of peak performance, taking into account the ranking position and age categories. Materials and Methods: The sample comprised 210,455 runners in time-limited ultra-marathons (female 12 h = 23,706; female 24 h = 28,585; male 12 h = 61,594; male 24 h = 96,570) competing between 1876 and 2020 and aged 18 to 86 years. The age of peak performance was tested according to their ranking position (first−third; fourth−tenth and >tenth position) and taking into account their running speed in different age categories (<30 years; 31−40 years; 41−50 years; 51−60 years; >60 years), using the Kruskal−Wallis test, followed by the Bonferroni adjustment. Results: An increase in the number of participants and a decrease in running speed were observed across the years. For both events, the sex differences in performance decreased over time. The sex differences showed that male runners performed better than female runners, but the lowest differences in recent years were observed in the 24 h ultra-marathons. A positive trend in age across the years was found with an increase in mean age ("before 1989" = 40.33 ± 10.07 years; "1990−1999" = 44.16 ± 10.37 years; "2000−2009" = 45.99 ± 10.33 years; "2010−2020" = 45.62 ± 10.80 years). Male runners in 24 h races were the oldest (46.13 ± 10.83 years), while female runners in 12 h races were the youngest (43.46 ± 10.16 years). Athletes ranked first−third position were the youngest (female 12 h = 41.19 ± 8.87 years; female 24 h = 42.19 ± 8.50 years; male 12 h = 42.03 ± 9.40 years; male 24 h = 43.55 ± 9.03 years). When age categories were considered, the best performance was found for athletes aged between 41 and 50 years (female 12 h 6.48 ± 1.74 km/h; female 24 h 5.64 ± 1.68 km/h; male 12 h 7.19 ± 1.90 km/h; male 24 h 6.03 ± 1.78 km/h). Conclusion: A positive trend in participation in 12 h and 24 h ultra-marathons was shown across the years; however, athletes were becoming slower and older. The fastest athletes were the youngest ones, but when age intervals were considered, the age of peak performance was between 41 and 50 years.

The Sex Difference in 6-h Ultra-Marathon Running-The Worldwide Trends from 1982 to 2020.

Background and Objectives: The 6-h ultra-marathon is the shortest time-limited ultra-marathon race, but little has been investigated regarding this race format. Previously, only the age of peak performance in the context of longer time-limited ultra-marathons was determined. The purpose of this study was to investigate the trends in 6-h ultra-marathon races from 1982 to 2020 for female and male ultra-runners, the participation and performance by countries, the age of peak performance, and the differences in performance regarding countries. Materials and Methods: The sample included 23,203 female ultra-runners, aged 18-83 years, and 87,264 male ultra-runners, aged 18-85 years, who were finishers in a 6-h ultra-marathon held between 1982 and 2020. The age of peak performance was tested using the Kruskal-Wallis test, followed by the Bonferroni Correction. The difference in performance by countries was verified using a linear regression model with the fastest runners from Russia in women, and Tunisia in men, used as reference. Results: Over the years, the men-to-women ratio decreased. The mean age was 43.20 ± 9.30 years for female and 46.09 ± 10.17 years for male runners. Athletes in younger age groups were faster than athletes in older age groups. Most female and male participants originated from Germany. Women from Russia (10.01 ± 1.28 km/h) and men from Tunisia (12.16 ± 1.46 km/h) were the fastest. Conclusions: In summary, in 6-h ultra-marathons held between 1982 and 2020, the participation for both women and men increased, while the men-to-women ratio decreased. The mean age was higher in men compared to women. Most female and male runners originated from Germany, but the fastest women were from Russia, and the fastest men from Tunisia. Future studies need to investigate whether Russian women and Tunisian men are also the best in other distance-limited ultra-marathon races, such as 12-h and 24-h.

The beginning of success: Performance trends and cut-off values for junior and the U23 triathlon categories.

BACKGROUND: This study sought to determine cut-off values for each triathlon discipline to achieve podium in Junior (short distance; 750 m swim, 20 km cycle and 5 km run) and U23 (standard/Olympic distance; 1.5 km swim, 40 km cycle and 10 km run) triathlon events. Additionally, we aimed to investigate which discipline has the largest relationship with overall Junior and U23 triathlon performance, and the effect of sex and time in performance trends. METHODS: We included all data from Junior and U23 official races (International Triathlon Federation; ITU) of Junior (n = 3,314 finishes) and U23 (n = 5,092 finishes) categories held from 1999 to 2018. RESULTS: Men were significantly faster than women in both Junior (11.13%) and U23 (12.28%) categories. Swimming and cycling times were faster in 2009-2018 than in the 1999-2008 decade for men (3.36%; 6.49%), women junior (6.50%; 7.09%), men (0.15%; 3.46%) and women U23 (1.61%; 3.31%) respectively. Cycling was the discipline with the greatest influence on overall triathlon performance in Junior and U23 categories, regardless of sex or rank position. The cut-off values for the Junior category were (men/women): swimming, 9.2/9.4 min; cycling, 31.9/38.2 min; running, 16.8/18.9 min. U23's cut-off values were (men/women): swim, 18.0/19.4 min, cycling: 63.4/70.1 min; run, 33.9/38.7 min. CONCLUSION: Cycling was the discipline with the greatest influence on overall performance for both men and women in Junior and U23 categories. Moreover, swimming and cycling performances increased over the years for both sexes.

Effects of congested match periods on acceleration and deceleration profiles in professional soccer.

The aim of the present study was to analyse the influence of congested periods of matches on the acceleration (Acc) and deceleration (Dec) profiles of elite soccer players. Twenty-three elite male professional soccer players participated in the study across 31 official matches. Assessed periods included: (i) congested periods (three to four days between games), and (ii) non-congested periods (more than four days between games). Physical activity during matches was recorded during games using a 10Hz global positioning system device, coupled with a 100 Hz accelerometer, and was analysed according to the periods. Maximal Acc- (73.2 ± 20.3 vs. 84.918.5 m), high Acc- (244.0 ± 49.5 vs. 267.0 ± 37.8 m), maximal Dec- (139.0 ± 44.8 vs. 152.039.3 m) and the total decelerating- distance (5132 ± 690 vs. 5245 ± 552 m) were lower in congested than in non-congested periods (p < 0.05, effect size 0.31-0.70). Neither a main effect of playing position nor a period*playing position interaction on Acc and Dec were observed (p > 0.05). It was concluded that Acc and Dec match activities were significantly affected during congested periods compared to non-congested highlighting a possible fatigue accumulation being responsible for the observed decrement in physical activity. Monitoring Acc and Dec metrics throughout particular periods of congested fixtures amongst professional soccer teams is advised and may be a way to assess physical and fatigue status.

Training, psychometric status, biological markers and neuromuscular fatigue in soccer.

The study examined the relationship between psychometric status, neuromuscular, and biochemical markers of fatigue in response to an intensified training (IT) period in soccer. Fifteen professional soccer players volunteered to participate in the study (mean ± SD: age: 25 ± 1 years; body height: 179 ± 7 cm, body mass: 73.7 ± 16.2 kg, experience: 13.2 ± 3 years). Training load, monotony, strain, Hooper index and total quality recovery (TQR) were determined for each training session during a 2-week of IT. Counter-movement jump (CMJ) and biochemical responses [testosterone, cortisol, testosterone-to-cortisol ratio (T/C ratio), creatine kinase, and C-reactive protein] were collected before and after IT. Results showed that IT induced significant increases in cortisol, creatine kinase and C-reactive protein and significant decreases in T/C ratio and CMJ performance from before to after IT (p < 0.01, p < 0.001, p < 0.001, p < 0.01, p < 0.05, respectively). However, testosterone did not differ from before to after IT (p > 0.05). Training loads were positively correlated with Hooper index (p < 0.05) and negatively correlated with total quality recovery (p < 0.05). Hooper index was positively correlated with cortisol (p < 0.05), T/C ratio (p < 0.01), and creatine kinase (p < 0.01), and negatively correlated with CMJ (p < 0.05). Furthermore, TQR was negatively correlated with T/C ratio (p < 0.01), creatine kinase (p < 0.001), and C-reactive protein (p < 0.05), and positively correlated with CMJ (p < 0.01). Neuromuscular fatigue, muscle damage, and change in the anabolic/catabolic state induced by the IT were related to well-being and perceived recovery state among professional soccer players.

Body composition adaptations to lower-body plyometric training: a systematic review and meta-analysis.

The aim of this meta-analysis was to explore the effects of plyometric jump training (PJT) on body composition parameters among males. Relevant articles were searched in the electronic databases PubMed, MEDLINE, WOS, and SCOPUS, using the key words "ballistic", "complex", "explosive", "force-velocity", "plyometric", "stretch-shortening cycle", "jump", "training", and "body composition". We included randomized controlled trials (RCTs) that investigating the effects of PJT in healthy male's body composition (e.g., muscle mass; body fat), irrespective of age. From database searching 21 RCTs were included (separate experimental groups = 28; pooled number of participants = 594). Compared to control, PJT produced significant increases in total leg muscle volume (small ES = 0.55, p = 0.009), thigh muscle volume (small ES = 0.38, p = 0.043), thigh girth (large ES = 1.78, p = 0.011), calf girth (large ES = 1.89, p = 0.022), and muscle pennation angle (small ES = 0.53, p = 0.040). However, we did not find significant difference between PJT and control for muscle cross-sectional area, body fat, and skinfold thickness. Heterogeneity remained low-to-moderate for most analyses, and using the Egger's test publication bias was not found in any of the analyses (p = 0.300-0.900). No injuries were reported among the included studies. PJT seems to be an effective and safe mode of exercise for increasing leg muscle volume, thigh muscle volume, thigh and calf girth, and muscle pennation angle. Therefore, PJT may be effective to improve muscle size and architecture, with potential implications in several clinical and sport-related contexts.

Effects of strength training with elastic band programme on fitness components in young female handball players: a randomized controlled trial.

This study examined the effect of a 10-week programme of strength training with elastic band (STEB) on fitness components in young female handball players. Twenty-six young female handball players (aged 15.8 ± 0.2 years) from the same club participated in this study. They were randomly assigned between experimental (EG; n = 13) and control (CG; n = 13) groups. The EG performed the STEB, replacing some handball-specific drills in the regular handball training. The CG followed the regular handball training (i.e., mainly technical-tactical drills, small sided and simulated games, and injury prevention drills). Two-way analyses of variance were used to assess: handgrip; back extensor strength; medicine ball throw; 30 m sprint times; Modified Illinois change-of-direction (Illinois-MT); four jump tests: squat jump (SJ), countermovement jump (CMJ), countermovement jump with arm swing (CMJA) and five-jump test (5JT); static (Stork test) and dynamic balance (Y Balance Test); and repeated sprint T-test (RSTT). Results revealed significant gains in handgrip - right (p < 0.001, d = 1.75: large), handgrip - left (p < 0.001, d = 2.52: large), back extensor (p < 0.001, d = 2.01: large), and medicine ball throw (p = 0.002, d = 0.95: large) with EG compared to the CG. The EG also demonstrated greater improvement in sprint performance over 20 m (Δ = 10.6%, p = 0.001, d = 1.07: large) and 30 m (Δ = 7.2%, p < 0.0001, d = 1.56: large) compared to the CG. The EG showed better Illinois-MT (Δ = 5.6%, p = 0.034, d = 0.62: medium) compared to the CG. Further, EG posted significant improvements in the SJ (Δ = 17.3%, p = 0.048, d = 0.58: medium), CMJ (Δ = 17.7%, p = 0.017 d = 0.71: medium), and CMJA (Δ = 16.3%, p = 0.019, d = 0.69: medium) compared to the CG. Similarly, the EG exhibited significant improvement in RSTT best time [p = 0.025, d = 0.66 (medium)], RSTT mean time [p = 0.019, d = 0.69 (medium)] and RSTT total time [p = 0.019, d = 0.69 (medium)] compared to the CG. In conclusion, the 10-week STEB improved the physical abilities in young female handball players.

Fear of failure in Brazilian runners.

This study aims to investigate the fear or failure (FoF) in Brazilian runners of both sex, performance levels and age categories, as well as to verify the relationship between FoF and socioeconomic status (SES). Sample size as composed by 916. Age, sex, body height, body weight, SES, and running pace were self-reported. The Multidimensional Questionnaire of FoF was applied in an online platform. Running pace, and SES were categorized and processed through multivariate analysis and Spearman correlations, with the p-value set at 0.05. Female runners with better performance (2.13 ± 0.74) and younger (2.16 ± 0.80), as a well as male runners with worse performance (2.04 ± 0.69) and older (2.04 ± 0.89) presented the highest values of FoF. Among women, SES was negatively associated with FoF (r = -0.144; p = 0.006), while a positive association between running pace and SES was observed among men (r = 0.290; p < 0.001). Non-professional Brazilian runners presented low values of FoF.

Reduced level of physical activity during COVID-19 pandemic is associated with depression and anxiety levels: an internet-based survey.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has resulted in a strong negative impact on economic and social life worldwide. It has also negatively influenced people's general health and quality of life. The aim of the present study was to study the impact of social distancing on physical activity level, and the association between mood state (depression and anxiety level) or sex with actual physical activity levels, the change in physical activity caused by social distancing period, the adhesion level to social distancing, the adoption time of social distancing, family income and age. METHODS: A self-administered questionnaire with personal, quarantine, physical activity, and mood state disorders information's was answered by 2140 Brazilians of both sex who were recruited through online advertising. RESULTS: The physical activity level adopted during the period of social distancing (3.5 ± 0.8) was lower than that the adopted prior to the pandemic period (2.9 ± 1.1, p < 0.001). Thirty percent of the participants presented symptoms of moderate/severe depression and 23.3% displayed moderate/severe anxiety symptoms. A greater presence of symptoms related to anxiety and depression were associated with low physical activity levels, low family monthly income, and younger age. A higher percentage of men who had no mood disorders was observed among those who were very active than among those less active. CONCLUSION: The COVID-19 pandemic has a negative impact on physical activity. Those who reduced their level of physical activity had the highest levels of mood disorders. Therefore, physical activity programs should be encouraged, while respecting the necessary social distancing to prevent the spread of Severe Acute Respiratory Syndrome Coronavirus 2.

The effects of two different intensities of aerobic training protocols on pain and serum neuro-biomarkers in women migraineurs: a randomized controlled trail.

OBJECTIVES: We have a weak understanding of how aerobic training may influence migraine, and the optimal parameters for exercise regimens as migraine therapy are not clear. The objectives of this study were to assess, first, effects of two different intensities of aerobic exercise on migraine headache indices; second, serum neuro-biomarker in women migraineurs. METHODS: A total of 45 non-athlete female migraine patients were selected by a neurologist and randomly divided into three groups: control (CON), moderate-intensity aerobic training (MOD T), and high-intensity aerobic training (HIGH T). Before and after the training protocol, body composition factors, migraine pain indices, VO2max, and serum Adenylate-Cyclase Activating Polypeptide (PACAP) and Substance P (SP) were measured. Exercise training protocol includes two different intensities of aerobic exercise: Moderate (13-15 Borg Scale, 60-80% HRmax) and High (15-17 Borg Scale, 65-95% HRmax). RESULTS: Moderate-intensity aerobic training (MOD T) reduced headache intensity, frequency, and duration in women with migraine (p < 0.001, for all). Also, high-intensity aerobic training (HIGH T) reduced headache intensity, frequency, and duration (p < 0.001, for all). However, for headache intensity and duration, MOD T was effective rather than HIGH T (p < 0.001; p ≤ 0.05, respectively). In addition, neither MOD T nor HIGH T could not alter PACAP and SP contents (p = 0.712; p = 0.249, respectively). CONCLUSIONS: Our results demonstrated that either MOD T or HIGH T could modify migraine pain indices but neither MOD T nor HIGH T could not alter the PACAP and SP contents in women with migraine.

Participation and Performance in the Oldest Ultramarathon-Comrades Marathon 1921-2019.

Participation and performance trends have been analyzed for different ultramarathons for limited time periods. This study examined trends in participation and performance in the oldest ultramarathon in the world, the 'Comrades Marathon' (South Africa), during a century (1921-2019). Data from www.ultra-marathon.org on 100 000 unique finishers were analysed using different general linear models. Women represented 4.2% of the total sample (n=4152), and the first women ran this race in 1978. Before the year 1965, the number of participants in the race ranged between 5 and 35 athletes, then started to grow exponentially until mid 90's. An increase in finishers in the 70 s mainly due to an increase in male athletes in age groups 30-39, 40-49 and 50-59 years was observed (p<0.001). A stable running speed for overall women and men but an improvement in performance for the annual top five women and men were shown (p<0.001). Male runners were faster than female runners for all age groups (p<0.001). While overall performance was not improved across years, the annual top five women and men were able to improve their performance over years.

Exergaming and Aquatic Exercises Affect Lung Function and Weight Loss in Obese Children.

We investigated the effect of exergames and aquatic exercises on lung function and weight loss in obese children. Sixty-one obese male primary-school children were randomly allocated to video game, aquatic exercise, and control groups. Lung functions and anthropometric variables were measured before and after the intervention and after one month (follow-up). In the video game group, an Xbox Kinect game was played for 60 min during three sessions a week. The aquatic aerobic exercise was performed three times per week and consisted of a warm-up, main exercises, and a cool down phase. For the video game group, there was a significant reduction in body weight between (i) pre- and (ii) post-intervention and follow-up. In the aquatic exercise group, there was a significant reduction in body weight between pre- and post-intervention and between pre-intervention and follow-up. Both exercise groups improved the waist/hip ratio index compared to the control group. Forced vital capacity was significantly improved in the follow-up of the video game group and the aquatic exercise group compared to the control group. A significant improvement was found in forced expiratory volume in the first second at post-intervention and follow-up in the video game and the aquatic exercise groups. Exergames and aquatic exercises improved weight loss and lung function in obese children.

Participation and Performance Trends in the ITU Duathlon World Championship From 2003 to 2017.

ABSTRACT: Nikolaidis, PT, Villiger, E, and Knechtle, B. Participation and performance trends in the ITU Duathlon World Championship from 2003 to 2017. J Strength Cond Res 35(4): 1127-1133, 2021-Participation and performance across years have been studied extensively in various endurance and ultra-endurance sports; however, less information exists with regards to duathlon (i.e., Run 1, Bike, and Run 2). The aim of this study was to examine performance and participation trends of duathletes competing either to short (10-km Run 1, 50-km Bike, and 5-km Run 2) or to long distance (10-km Run 1, 150-km Bike, and 30-km Run 2) in the Powerman World Championship "Powerman Zofingen." We analyzed 7,951 finishers (women, n = 1,236, age 36.7 ± 9.1 years; men, n = 6,715, 40.1 ± 10.1 years) competing in "Powerman Zofingen" from 2003 to 2017. Men were faster than women by 8.2% (171 ± 21 minutes vs. 186 ± 21 minutes, p < 0.001, η2 = 0.068) and 7.5% (502 ± 57 minutes vs. 543 ± 64 minutes, p < 0.001, η2 = 0.068) in the short and long distances, respectively. Women were younger than men by 4.6 years (35.0 ± 9.0 years vs. 39.6 ± 10.5 years, p < 0.001, η2 = 0.026) and 1.8 years (38.8 ± 8.7 years vs. 40.6 ± 9.5 years, p < 0.001, η2 = 0.005) in the short and long distances, respectively. An increase of women finishers across years in the long distance was observed (e.g., n = 19 in 2003 and n = 58 in 2017; p < 0.001), whereas no change was shown in short distance and men finishers. The men-to-women ratio (MWR) decreased across years in the long, but not in the short distance. No change of race time across years was observed. The sex difference in race time increased in long distance (p = 0.014), whereas it did not change in the short. Age increased across years in both sexes and distances (p < 0.001). The sex difference in age decreased in the long (p = 0.007), but not in the short distance. In summary, the number of women finishers increased and the MWR decreased in the long distance. The age of the finishers increased across years, and their performance remained unchanged. The increase of the sex difference in race time in the long distance might be attributed to the increased number of women finishers.

Physiological Responses to Swimming Repetitive "Ice Miles".

ABSTRACT: Knechtle, B, Stjepanovic, M, Knechtle, C, Rosemann, T, Sousa, CV, and Nikolaidis, PT. Physiological responses to swimming repetitive "Ice Miles." J Strength Cond Res 35(2): 487-494, 2021-"Ice Mile" swimming (i.e., 1,608 m in water of below 5° C) is becoming increasingly popular. Since the foundation of the International Ice Swimming Association (IISA) in 2009, official races are held as World Cup Races and World Championships. Ice swimming was a demonstration sport at the 2014 Winter Olympics in Sochi, Russia. This case study aimed to identify core body temperature and selected hematological and biochemical parameters before and after repeated "Ice Miles." An experienced ice swimmer completed 6 consecutive Ice Miles within 2 days. Three Ice Miles adhered to the strict criteria for the definition of Ice Miles, whereas the other 3 were very close (i.e., 5.2, 6.1, and 6.6° C) to the temperature limit. Swimming times, changes in core body temperatures, and selected urinary and hematological parameters were recorded. The athlete showed after each Ice Mile a metabolic acidosis (i.e., an increase in lactate and TCO2; a decrease in base excess and HCO3-) and an increase in blood glucose, cortisol, and creatine kinase concentration. The decrease in pH correlated significantly and negatively with the increase in cortisol level, indicating that this intense exercise causes a metabolic stress. The change in core body temperature between start and finish was negatively associated with metabolic acidosis. The increase in creatine kinase suggests skeletal muscle damages due to shivering after an Ice Mile. For athletes and coaches, swimming in cold water during Ice Miles leads to a metabolic acidosis, which the swimmer tries to compensate with a respiratory response. Considering the increasing popularity of ice swimming, the findings have practical value for swimmers and practitioners (e.g., coaches, exercise physiologists, and physicians) working with them because our results provide a detailed description of acute physiological responses to repeated swimming in cold conditions. These findings are of importance for athletes and coaches for National Championships and World Championships in Ice Swimming following the IISA rules.

Vitamin D and Stress Fractures in Sport: Preventive and Therapeutic Measures-A Narrative Review.

There are numerous risk factors for stress fractures that have been identified in literature. Among different risk factors, a prolonged lack of vitamin D (25(OH)D) can lead to stress fractures in athletes since 25(OH)D insufficiency is associated with an increased incidence of a fracture. A 25(OH)D value of <75.8 nmol/L is a risk factor for a stress fracture. 25(OH)D deficiency is, however, only one of several potential risk factors. Well-documented risk factors for a stress fracture include female sex, white ethnicity, older age, taller stature, lower aerobic fitness, prior physical inactivity, greater amounts of current physical training, thinner bones, 25(OH)D deficiency, iron deficiency, menstrual disturbances, and inadequate intake of 25(OH)D and/or calcium. Stress fractures are not uncommon in athletes and affect around 20% of all competitors. Most athletes with a stress fracture are under 25 years of age. Stress fractures can affect every sporty person, from weekend athletes to top athletes. Stress fractures are common in certain sports disciplines such as basketball, baseball, athletics, rowing, soccer, aerobics, and classical ballet. The lower extremity is increasingly affected for stress fractures with the locations of the tibia, metatarsalia and pelvis. Regarding prevention and therapy, 25(OH)D seems to play an important role. Athletes should have an evaluation of 25(OH)D -dependent calcium homeostasis based on laboratory tests of 25-OH-D3, calcium, creatinine, and parathyroid hormone. In case of a deficiency of 25(OH)D, normal blood levels of ≥30 ng/mL may be restored by optimizing the athlete's lifestyle and, if appropriate, an oral substitution of 25(OH)D. Very recent studies suggested that the prevalence of stress fractures decreased when athletes are supplemented daily with 800 IU 25(OH)D and 2000 mg calcium. Recommendations of daily 25(OH)D intake may go up to 2000 IU of 25(OH)D per day.