Two Weeks of High-Intensity Interval Training in Combination With a Non-thermal Diffuse Ultrasound Device Improves Lipid Profile and Reduces Body Fat Percentage in Overweight Women.

This study evaluated the effectiveness of an innovative strategy which combined low-frequency ultra sound (LOFU) with high-intensity interval training (HIIT) to improve physical fitness and promote body fat loss in overweight sedentary women. A placebo controlled, parallel group randomized experimental design was used to investigate the efficacy of a 2-week combined LOFU and HIIT program (3 sessions per week). Participants were allocated into either the Experimental HIIT group (HIITEXP, n = 10) or Placebo HIIT group (HIITPLA, n = 10). Baseline exercise testing (maximal oxygen uptake, lower limb strength and substrate oxidation test), dietary assessment, anthropometric measures and blood sampling were completed in week 1 and repeated in week 4 to determine changes following the program (Post-HIIT). During each training session, the HIITEXP and HIITPLA groups wore a non-thermal diffuse ultrasound belt. However, the belt was only switched on for the HIITEXP group. Delta change scores were calculated for body weight, body fat percentage (Fat%), muscle mass, V . O2 max, hip and waist circumferences, and all lipid variables from Baseline to Post-HIIT. Statistical analysis was completed using a repeated-measures factorial analysis of variance by group (HIITPLA and HIITEXP) and time (Baseline and Post-HIIT). Results showed significant improvements in maximal oxygen uptake (HIITEXP; Baseline 24.7 ± 5.4 mL kg-1 min-1, Post-HIIT 28.1 ± 5.5 mL kg-1 min-1 and HIITPLA; Baseline 28.4 ± 5.9 mL kg-1 min-1, Post-HIIT 31.4 ± 5.5 mL kg-1 min-1) for both groups. Significant decreases in Fat% (HIITEXP; Baseline 32.7 ± 3.2%, Post-HIIT 28.9 ± 3.5% and HIITPLA; Baseline 28.9 ± 3.5%, Post-HIIT 28.9 ± 3.4% kg), waist circumference (HIITEXP; Baseline 95.8 ± 9.6 cm, Post-HIIT 89.3 ± 8.9 cm and HIITPLA; Baseline 104.3 ± 3.5 cm, Post-HIIT 103.6 ± 3.4 cm) and triglycerides (HIITEXP; -29.2%, HIITPLA; -6.7%) were observed in the HIITEXP group only. These results show that HIIT combined with LOFU was an effective intervention to improve body composition, lipid profile, and fitness. This combined strategy allowed overweight, sedentary women to achieve positive health outcomes in as little as 2 weeks.

Epidemiology of Judo-Related Injuries in 21 Seasons of Competitions in France: A Prospective Study of Relevant Traumatic Injuries.

BACKGROUND: Judo is a full-contact fighting sport that may lead to severe injuries. There are limited data available on the incidence of judo-related injuries. The French Judo Federation has established a surveillance system to document the frequency and type of injuries during judo competitions. PURPOSE: To describe the incidence rates and types of judo-related traumatic injuries during 21 seasons of competitions in France with respect to athlete (judoka) age, sex, and level of performance. STUDY DESIGN: Descriptive epidemiology study. METHODS: Between 1993 and 2014, each physician in charge of each judo competition filled out a form in which he/she documented the number of competing judokas, the number of fights, the number of medical interventions, the specific type of traumatic injuries for each intervention, the number of fight interruptions, and the number of athletes removed from the competition venue because of an injury. The age, sex, and level of performance of each judoka were also documented. Variance analysis was applied to assess whether differences in incidence rates of injuries between groups were significant (Student t test and chi-square test). RESULTS: Surveillance of 421,670 fights demonstrated 3511 injuries in 316,203 judokas (incidence proportion, 1.1%). Among the injuries recorded, the most common were sprains (54.3%), fractures (15.6%), and dislocations (12.5%). Female athletes exhibited significantly higher incidence rates for knee sprains and elbow dislocations, whereas male athletes exhibited a higher incidence rate for shoulder dislocations (P < .001 for all). Regarding age, higher incidence rates were observed in young adults (aged 18-20 years) for acromioclavicular sprains and in children (aged 10-14 years) for clavicle fractures compared with adults (aged 21-35 years) (P < .001 for both). Both young adult and adult athletes had a higher incidence rate of shoulder dislocations (P < .001). Regarding the level of performance, athletes competing at higher levels had a higher incidence rate of sprains to the knee (P < .001). CONCLUSION: During 21 years of surveillance of injuries in judo competitions in France, the incidence proportion of injuries was 1.1%. Significant differences in incidence rates demonstrated when considering age, sex, and level of performance may help in developing strategies to prevent traumatic injuries in the future.

Z-scores-based methods and their application to biological monitoring: an example in professional soccer players.

The clinical and biological follow-up of individuals, such as the biological passport for athletes, is typically based on the individual and longitudinal monitoring of hematological or urine markers. These follow-ups aim to identify abnormal behavior by comparing the individual's biological samples to an established baseline. These comparisons may be done via different ways, but each of them requires an appropriate extra population to compute the significance levels, which is a non-trivial issue. Moreover, it is not necessarily relevant to compare the measures of a biomarker of a professional athlete to that of a reference population (even restricted to other athletes), and a reasonable alternative is to detect the abnormal values by considering only the other measurements of the same athlete. Here we propose a simple adaptive statistic based on maxima of Z-scores that does not rely on the use of an extra population. We show that, in the Gaussian framework, it is a practical and relevant method for detecting abnormal values in a series of observations from the same individual. The distribution of this statistic does not depend on the individual parameters under the null hypothesis, and its quantiles can be computed using Monte Carlo simulations. The proposed method is tested on the 3-year follow-up of ferritin, serum iron, erythrocytes, hemoglobin, and hematocrit markers in 2577 elite male soccer players. For instance, if we consider the abnormal values for the hematocrit at a 5% level, we found that 5.57% of the selected cohort had at least one abnormal value (which is not significantly different from the expected false-discovery rate). The approach is a starting point for more elaborate models that would produce a refined individual baseline. The method can be extended to the Gaussian linear model, in order to include additional variables such as the age or exposure to altitude. The method could also be applied to other domains, such as the clinical patient follow-up in monitoring abnormal values of biological markers.

Understanding the Physiological Requirements of the Mountain Bike Cross-Country Olympic Race Format.

Objectives: To evaluate the physiological requirements imposed by the current mountain biking Cross-Country Olympic (XCO) format. Methods: Sixteen Cross-Country cyclists competing at national or international level participated in this study. All participants completed a simulated and a real official race on a cycling-accredited race track. Oxygen consumption (O2) and heart rate (HR) values expressed as %O2max and %HRmax, respectively, were divided into three physiological intensity zones. The first zone (Z1) was the physiological region below VT1, the second zone (Z2) corresponded to a region between VT1 and VT2, and the third zone (Z3) was located between VT2 and VO2max. For power output, an additional fourth zone was considered above maximal aerobic power (MAP). Results: When competing in the current XCO format, 37.0 ± 17.9% of the race is performed above the second ventilatory threshold at a mean intensity of 87% O2max and 25% of the race was spent above MAP. This contribution varied between laps, with a very high intensity during the first lap and more aerobic subsequent laps. The durations of most of the periods beyond MAP oscillated between 5 and 30 s. Between these short, repeated bursts, low-intensity periods of exercise were recorded. Conclusion: The current XCO race format is an acyclical and intermittent exercise comparable to high-intensity team sports. Moreover, our results highlight the relevance of O2 values when analyzing XCO performance, they should be combined with commonly used HR and/or power output data.

Collective effectiveness in the XV de France: selections and time matter.

The aim of this study was to quantify the impact of selections and shared selections in the rugby union. Players' names, positions, and number of selections were collected for all XV de France's games (1906-2014). Every team's percentage of renewal of workforce was calculated for backs and forwards. During the 1987-2014 period, all second row forwards (locks), halfbacks, and centres' shared selections (number of times when two players have competed together) were recreated. The Best vs. Rest method was applied to these remodelled dyads. They were analysed and compared with surrounding teammates as well as opponents. Head coaches similarly change their workforce for upcoming matches after winning or losing (around 30%), but losing teams renew significantly more positions in their line-ups. The recreated halfbacks, locks, and centres reveal a common pattern. Whether victorious or not, the 'renewed couples' victory percentage will congregate towards the XV de France's victory percentage. For all the best recreated couples, the cumulated number of selections for forwards' is always higher than the ones part of less efficient teams: 231.3 ± 80 vs. 212.9 ± 91 selections for locks' teammates (Effect sizes (ES) small, possibly positive, 54.8%). In best recreated couples, number 8's are significantly more experienced than their counterparts in less efficient pairs (ES small, likely positive, 76.3%). The XV de France's collective effectiveness relies on a balance between stability and workforce renewal, which allows the building of specific position interactions and builds on experimented forwards packs. Selections and shared selections are serious collective performance parameters associated with performance.

Periodization of Carbohydrate Intake: Short-Term Effect on Performance.

BACKGROUND: "Sleep-low" consists of a sequential periodization of carbohydrate (CHO) availability-low glycogen recovery after "train high" glycogen-depleting interval training, followed by an overnight-fast and light intensity training ("train low") the following day. This strategy leads to an upregulation of several exercise-responsive signaling proteins, but the chronic effect on performance has received less attention. We investigated the effects of short-term exposure to this strategy on endurance performance. METHODS: Following training familiarization, 11 trained cyclists were divided into two groups for a one-week intervention-one group implemented three cycles of periodized CHO intake to achieve the sleep-low strategy over six training sessions (SL, CHO intake: 6 g·kg-1·day-1), whereas the control group consumed an even distribution of CHO over the day (CON). Tests were a 2 h submaximal ride and a 20 km time trial. RESULTS: SL improved their performance (mean: +3.2%; p < 0.05) compared to CON. The improvement was associated with a change in pacing strategy with higher power output during the second part of the test. No change in substrate utilization was observed after the training period for either group. CONCLUSION: Implementing the "sleep-low" strategy for one week improved performance by the same magnitude previously seen in a three-week intervention, without any significant changes in selected markers of metabolism.

The impact of sleeping with reduced glycogen stores on immunity and sleep in triathletes.

PURPOSE: We investigated the effects of a 3-week dietary periodization on immunity and sleep in triathletes. METHODS: 21 triathletes were divided into two groups with different nutritional guidelines during a 3-week endurance training program including nine twice a day sessions with lowered (SL group) or maintained (CON group) glycogen availability during the overnight recovery period. In addition to performance tests, sleep was monitored every night. Systemic and mucosal immune parameters as well as the incidence of URTI were monitored every week of the training/nutrition protocol. Two-ways ANOVA and effect sizes were used to examine differences in dependent variables between groups at each time point. RESULTS: The SL group significantly improved 10 km running performance (-1 min 13 s, P < 0.01, d = 0.38), whereas no improvement was recorded in the CON group (-2 s, NS). No significant changes in white blood cells counts, plasma cortisol and IL-6 were recorded over the protocol in both groups. The vitamin D status decreased in similar proportions between groups, whereas salivary IgA decreased in the SL group only (P < 0.05, d = 0.23). The incidence of URTI was not altered in both groups. All participants in both groups went to bed earlier during the training program (SL -20 min, CON -27 min, P < 0.05, d = 0.28). In the SL group, only sleep efficiency slightly decreased by 1.1 % (P < 0.05, d = 0.25) and the fragmentation index tended to increase at the end of the protocol (P = 0.06). CONCLUSION: Sleeping and training the next morning regularly with reduced glycogen availability has minimal effects on selected markers of immunity, the incidence of URTI and sleeping patterns in trained athletes.

Enhanced Endurance Performance by Periodization of Carbohydrate Intake: "Sleep Low" Strategy.

PURPOSE: We investigated the effect of a chronic dietary periodization strategy on endurance performance in trained athletes. METHODS: Twenty-one triathletes (V˙O2max: 58.7 ± 5.7 mL·min(-1)·kg(-1)) were divided into two groups: a "sleep-low" (SL) (n = 11) and a control (CON) group (n = 10) consumed the same daily carbohydrate (CHO) intake (6 g·kg(-1)·d(-1)) but with different timing over the day to manipulate CHO availability before and after training sessions. The SL strategy consisted of a 3-wk training-diet intervention comprising three blocks of diet-exercise manipulations: 1) "train-high" interval training sessions in the evening with high-CHO availability, 2) overnight CHO restriction ("sleeping-low"), and 3) "train-low" sessions with low endogenous and exogenous CHO availability. The CON group followed the same training program but with high CHO availability throughout training sessions (no CHO restriction overnight, training sessions with exogenous CHO provision). RESULTS: There was a significant improvement in delta efficiency during submaximal cycling for SL versus CON (CON, +1.4% ± 9.3%; SL, +11% ± 15%, P < 0.05). SL also improved supramaximal cycling to exhaustion at 150% of peak aerobic power (CON, +1.63% ± 12.4%; SL, +12.5% ± 19.0%; P = 0.06) and 10-km running performance (CON, -0.10% ± 2.03%; SL, -2.9% ± 2.15%; P < 0.05). Fat mass was decreased in SL (CON, -2.6 ± 7.4; SL, -8.5% ± 7.4% before; P < 0.01), but not lean mass (CON, -0.22 ± 1.0; SL, -0.16% ± 1.7% PRE). CONCLUSION: Short-term periodization of dietary CHO availability around selected training sessions promoted significant improvements in submaximal cycling economy, as well as supramaximal cycling capacity and 10-km running time in trained endurance athletes.

Eighty percent of French sport winners in Olympic, World and Europeans competitions have mutations in the hemochromatosis HFE gene.

The HFE gene encodes a protein involved in iron homeostasis; individuals with mutations in both alleles develop hemochromatosis. 27% of the French population is heterozygous for mutations in this gene. We found that 80% of the French athletes who won international competitions in rowing, Nordic skiing and judo display mutations in one allele of HFE, thus demonstrating the existence of a favourable phenotype linked to this heterozygosity.

Comparison of between-training-sessions recovery strategies for world-class BMX pilots.

PURPOSE: To assess the impact of between-training-sessions recovery strategies (passive [PAS], active [ACT], cold-water immersion [CWI], and ingestion of a recovery drink [NUTR]) on maximal cycling performance, perceptions of delayed-onset muscle soreness (DOMS), and fatigue in world-class BMX riders. METHODS: Eleven elite BMX athletes, members of the French national team (top country in the 2011 international ranking, 4 medals at the 2012 World Championships, top European country), participated in the study, which involved standardized training periods. Athletes performed 3 maximal-sprint power tests: the first day of the week before the training session and before and after training on the third day of the week (D3). The recovery strategy was randomly assigned to each participant on day 2 immediately after the last training period of the day. Perceptions of DOMS and general fatigue were recorded on D3. RESULTS: After training on D3, the decrease in maximal-sprint power (Pmax) was significantly greater for PAS than with CWI (P=.02) and NUTR (P=.018). Similar results were found with ACT (vs CWI P=.044, and vs NUTR P=.042). Self-reported DOMS and fatigue were significantly greater after PAS than after other strategies. CONCLUSIONS: For elite BMX riders, between training days, nutritional and/or CWI recovery strategies appear to be best for reducing muscle fatigue and increasing the capacity to withstand the training schedule.

Environment and scheduling effects on sprint and middle distance running performances.

PURPOSE: Achievement of athletes' performances is related to several factors including physiological, environmental and institutional cycles where physical characteristics are involved. The objective of this study is to analyse the performance achieved in professional sprint and middle-distance running events (100 m to 1500 m) depending on the organization of the annual calendar of track events and their environmental conditions. METHODS: From 2002 to 2008, all performances of the Top 50 international athletes in the 100 m to 1500 m races (men and women) are collected. The historical series of world records and the 10 best annual performances in these events, amounted to a total of 26,544 performances, are also included in the study. RESULTS: Two periods with a higher frequency of peak performances are observed. The first peak occurs around the 27.15(th) ±0.21 week (first week of July) and the second peak around 34.75(th) ±0.14 week (fourth week of August). The second peak tends to be the time of major international competitions (Olympic Games, World Championships, and European Championships) and could be characterized as an institutional moment. The first one, however, corresponds to an environmental optimum as measured by the narrowing of the temperature range at the highest performance around 23.25±3.26°C. CONCLUSIONS: This is the first study to demonstrate that there are two performance peaks at a specific time of year (27th and 34th weeks) in sprint and middle distance. Both institutional and ecophysiological aspects contribute to performance in the 100 m to 1500 m best performances and define the contours of human possibilities. Sport institutions may take this into account in order to provide ideal conditions to improve the next records.

No effect of weight cycling on the post-career BMI of weight class elite athletes.

BACKGROUND: Repetitions of pre-competition weight-loss diets done by athletes participating in weight class sports can be regarded as periods of weight cycling. The aim of the present study is to identify the long term post-career (22 years) evolutionary profile of athletes' BMI after such weight cycling. METHODS: One hundred and thirty-six retired French athletes who participated in major international competitions in weight class sports (rowers, wrestlers, boxers, and judokas) were included. Former and current body mass, height, dietary characteristics during the career (annual frequency, amount of weight lost), current physical activity, and answers on the eating-attitude test were collected by phone interview (consistency was tested by comparison with measured weight). We performed ANOVA tests for comparison between groups (sport, dieting), post-hoc tests (Bonferroni test) to identify differences within groups. BMI's changes were treated using a mixed model. RESULTS: The recorded weight changes did not depend upon time since retirement. Between 18 y and 50 y, athletes' BMI increased by 3.2 kg/m(2) compared to the 4.2 kg/m(2) increase in the general population. This increase was independent of the number of diets during the career. Retired athletes declared a mean weekly physical activity of 4.8 h ± 4.3. The eating-attitude test showed low scores for all sports without any correlation to diet characteristics. CONCLUSION: Weight cycling during an athletic career does not induce a massive weight gain after retirement, probably due to the high level of physical activity still practiced after retirement by these athletes.