Julio Calleja-González

Running Pace Decrease during a Marathon Is Positively Related to Blood Markers of Muscle Damage

Background Completing a marathon is one of the most challenging sports activities, yet the source of running fatigue during this event is not completely understood. The aim of this investigation was to determine the cause(s) of running fatigue during a marathon in warm weather. Methodology/Principal Findings We recruited 40 amateur runners (34 men and 6 women) for the study. Before the race, body core temperature, body mass, leg muscle power output during a countermovement jump, and blood samples were obtained. During the marathon (27 °C; 27% relative humidity) running fatigue was measured as the pace reduction from the first 5-km to the end of the race. Within 3 min after the marathon, the same pre-exercise variables were obtained. Results Marathoners reduced their running pace from 3.5 ± 0.4 m/s after 5-km to 2.9 ± 0.6 m/s at the end of the race (P<0.05), although the running fatigue experienced by the marathoners was uneven. Marathoners with greater running fatigue (> 15% pace reduction) had elevated post-race myoglobin (1318 ± 1411 v 623 ± 391 µg L−1; P<0.05), lactate dehydrogenase (687 ± 151 v 583 ± 117 U L−1; P<0.05), and creatine kinase (564 ± 469 v 363 ± 158 U L−1; P = 0.07) in comparison with marathoners that preserved their running pace reasonably well throughout the race. However, they did not differ in their body mass change (−3.1 ± 1.0 v −3.0 ± 1.0%; P = 0.60) or post-race body temperature (38.7 ± 0.7 v 38.9 ± 0.9 °C; P = 0.35). Conclusions/Significance Running pace decline during a marathon was positively related with muscle breakdown blood markers. To elucidate if muscle damage during a marathon is related to mechanistic or metabolic factors requires further investigation.

Effects of sports massage and intermittent cold-water immersion on recovery from matches by basketball players

Abstract The aim of this study was to compare the effects of intermittent cold-water immersion and massage on perceptual and performance markers of recovery by basketball players after competitive matches. Eight men (age 23 ± 3 years; stature 190.5 ± 8.9 cm; body mass 90.3 ± 9.6 kg; body fat 12.8 ± 4.8%) and eight women (age 22 ± 2 years; stature 179.0 ± 8.5 cm; body mass 77.6 ± 9.2 kg; body fat 22.5 ± 6.6%) basketball players participated. Massage, cold-water immersion or control were applied immediately after competitive matches, followed by assessments of perceptual measures of recovery and physical performance, countermovement jump and repeated-sprint ability 24 h after intervention. There was lower perception of fatigue overall and in the legs immediately after the massage and cold-water immersion condition (P < 0.001; = 0.91). Furthermore, women had a lower perception of fatigue in cold-water immersion than massage at any testing time (P < 0.001; = 0.37). Jump performance was greater after cold-water immersion than the control condition (P = 0.037, = 0.37). There was no effect of any of the recovery interventions on repeated-sprint measures (P at best 0.067, at best 0.68). The results suggest that both massage and cold-water immersion improve perceptual measures of recovery. Furthermore, cold-water immersion improves jump performance although neither such immersion nor massage had an effect on repeated-sprint ability. This suggests that, overall, cold-water immersion is more useful than massage in the recovery from basketball matches, especially in women.

The Biological Age of 14-year-old Boys and Success in Adult Soccer: Do Early Maturers Predominate in the Top-level Game?

Talent identification and development in soccer is often biased by maturation-related differences of young athletes. However, there is no information available about success rates for youth maturing at different tempos to achieve success in elite adult soccer. The purposes of this study were to determine the prevalence of different maturational groups among boys playing soccer, and to track them for competence in adult performance. A prospective cohort study design was used to follow 55, 14-year-old boys playing in Serbian youth soccer Division I over eight years. At the age of 14, biological age using skeletal age rates was determined, and participants were categorized as early maturers (EaM), normal maturers (NoM), and late maturers (LaM). Game competence for adult soccer at age 22 was described as elite if an individual played for clubs competing in top-five international soccer leagues (La Liga, Premier League, Bundesliga, Serie A, and Ligue 1), and/or has become a member of an adult National team. Among boys in our study group, 43.8% were categorized as EaM, 35.4% as NoM, and 20.8% as LaM (P = 0.11). A significant difference in biological age was found among maturational groups at age 14, with EaM > NoM > LaM (P > 0.0001). When assessed for adult soccer competence, 33.3% of participants (16 out of 48 players) succeed in achieving elite level. Elite soccer competence acquired 60.1% players from the group of LaM, 38.1% from NoM, and 11.8% from EaM (P > 0.0001). Our comparative analysis suggests that soccer excludes early maturing boys and favors late maturing boys as level of performance increases.

Ultra Short-Term Heart Rate Recovery after Maximal Exercise: Relations to Aerobic Power in Sportsmen

The main aim of the study was to investigate whether different levels of aerobic power influence heart rate (HR) responses during the first minute of recovery following maximal exercise in athletes. Thirty-two young male soccer players were recruited for the study during the final week of their training prior to [corrected] the competition. Following the maximal exercise on treadmill the participants were placed supine for 60 s of HR recording. The time between exercise cessation and the recovery HR measurement was kept as short as possible. At the end of exercise (i.e., the start of recovery), HRs were [corrected] was similar in both trials. At both 10 s and 20 s of recovery period, the players characterized by high aerobic power (> 60 ml/kg/ min) revealed significantly lower HR as compared to their sub-elite counterparts (< 50 ml/kg/min; P < 0.05). No differences between the groups were found at later stages of the analyzed post-exercise HR. The data suggest that the athletes characterized by high aerobic capacity could be better adapted to maximal exercise with faster recovery HR immediately following an exercise test. These results generally suggest that the aerobic power along with autonomic modulation might have played a role in the ultra short-term cardiovascular responses to all-out exercise.

Relationship between physiological parameters and performance during a half-ironman triathlon in the heat

Abstract Triathlon is a popular outdoor endurance sport performed under a variety of environmental conditions. The aim of this study was to assess physiological variables before and after a half-ironman triathlon in the heat and to analyse their relationship with performance. Thirty-four well-trained triathletes completed a half-ironman triathlon in a mean dry temperature of 29 ± 3ºC. Before and within 1 min after the end of the race, body mass, core temperature, maximal jump height and venous blood samples were obtained. Mean race time was 315 ± 40 min, with swimming (11 ± 1%), cycling (49 ± 2%) and running (40 ± 3%) representing different amounts of the total race time. At the end of the competition, body mass changed by −3.8 ± 1.6% and the change in body mass correlated positively with race time (r = 0.64; P < 0.001). Core temperature increased from 37.5 ± 0.6ºC to 38.8 ± 0.7ºC (P < 0.001) and post-race core temperature correlated negatively with race time (r = −0.47; P = 0.007). Race time correlated positively with the decrease in jump height (r = 0.38; P = 0.043), post-race serum creatine kinase (r = 0.55; P = 0.001) and myoglobin concentrations (r = 0.39; P = 0.022). In a half-ironman triathlon in the heat, greater reductions in body mass and higher post-competition core temperatures were present in faster triathletes. In contrast, slower triathletes presented higher levels of muscle damage and decreased muscle performance.

Exploring Game Performance in the National Basketball Association Using Player Tracking Data

Recent player tracking technology provides new information about basketball game performance. The aim of this study was to (i) compare the game performances of all-star and non all-star basketball players from the National Basketball Association (NBA), and (ii) describe the different basketball game performance profiles based on the different game roles. Archival data were obtained from all 2013-2014 regular season games (n = 1230). The variables analyzed included the points per game, minutes played and the game actions recorded by the player tracking system. To accomplish the first aim, the performance per minute of play was analyzed using a descriptive discriminant analysis to identify which variables best predict the all-star and non all-star playing categories. The all-star players showed slower velocities in defense and performed better in elbow touches, defensive rebounds, close touches, close points and pull-up points, possibly due to optimized attention processes that are key for perceiving the required appropriate environmental information. The second aim was addressed using a k-means cluster analysis, with the aim of creating maximal different performance profile groupings. Afterwards, a descriptive discriminant analysis identified which variables best predict the different playing clusters. The results identified different playing profile of performers, particularly related to the game roles of scoring, passing, defensive and all-round game behavior. Coaching staffs may apply this information to different players, while accounting for individual differences and functional variability, to optimize practice planning and, consequently, the game performances of individuals and teams.

Influence of anthropometric profile on physical performance in elite female volleyballers in relation to playing position

INTRODUCTION The anthropometric profile, specifically body composition, plays a crucial role in the physical performance of volleyballers. Since there are varying positions in volleyball, it is likely that differences exist in anthropometric and physical performance profiles among players due each roles specific physical requirements. OBJECTIVES The aims of this study were to analyze the anthropometric and physical performance profiles of elite female volleyballers, to determine any differences in these features among different playing positions. A further aim was to examine any relationship between anthropometric measures and measures of performance. METHODS This study assessed 42 female professional volleyball players (Age: 27.2±5.4 years). Players were categorized according to playing position: middle blockers (n=12), opposite hitters (n=6), outside hitters (n=12), setters (n=8), and liberos (n=4). Anthropometric measurements assessed were: height, weight, fat mass (5 skinfolds) musculoskeletal mass (5 corrected girths). Additionally, the physical performance parameters examined were: jump tests (vertical-jump and spike-jump), speed, agility, and strength tests (crunches test and overhead medicine ball throw). RESULTS In terms of height middle blockers were the tallest (186.5±1.4 cm), while liberos were the shortest (166.7±8.1 cm). There were significant differences in body mass among positions (p.

Relationship of body mass status with running and jumping performances in young basketball players.

PURPOSE the main purpose of this study was to examine the relationship of body mass (BM) status with running and jumping performances in young male basketball players. METHODS basketball players (n=72, age 12.9±2.8 yrs), who were grouped into U-12 (9-12 yrs), U-15 (12-15 yrs) and U-18 (15-18 yrs), performed a battery of anthropometric, running and jumping tests. We examined differences among age groups, and between normal weight and overweight players. RESULTS the results indicated significant and large differences among age groups in BM, height, body mass index (BMI), fat mass (FM), fat-free mass, speed, endurance, standing long jump, countermovement jump (CMJ), mean power in 30 s jumping test (Pmean) (p<0.001, η(2)≥0.23) with older players presenting higher values. Within each age group, overweight players had higher BM, BMI, body fat percentage and FM (p<0.05) than their normal weight counterparts. Overweight players had worst performance in running (sprint and endurance) and jumping (CMJ and Pmean) in U-12, and worst endurance in U-18 (p<0.05, |d|≥0.82) than normal-weight players, whereas there was no difference in U-15. CONCLUSIONS it was concluded that the relationship of BMI with running and jumping performances varied according to age. Based on these findings, trainers and coaches should focus on special intervention exercise and nutrition programs targeting optimal body mass especially in young basketball players, where the excess of body mass seemed to have the most detrimental effect on running and jumping performances.

Using testosterone and cortisol as biomarker for training individualization in elite basketball: a 4-year follow-up study.

Abstract Schelling, X, Calleja-González, J, Torres-Ronda, L, and Terrados, N. Using testosterone and cortisol as biomarker for training individualization in elite basketball. A 4-year follow-up study. J Strength Cond Res 29(2): 368–378, 2015—The purpose of this study was to determine the responses of testosterone and cortisol, with special reference to playing positions, playing time (PT), and phase of the season. We performed a follow-up study during 4 consecutive seasons to investigate the effects of PT, positional role, and phase of the season on anabolic-catabolic biomarkers (plasma total testosterone -TT- and cortisol -C-) on 20 professional male basketball players (27.0 ± 4.2 years; 24.4 ± 1.2 kg·m−2). First blood samples were collected right after the off-season period and considered as baseline. Samples were taken periodically every 4–6 weeks, always after a 24- to 36-hour break after the last game played. Statistical procedures were nonparametric mainly. Hormonal status was playing position-dependent, power forward (PF) showed the lowest TT values (median ± interquartile range [IQR]; PF: 18.1 ± 4.9; nmol·L−1), and small forwards showed the highest ones of cortisol (0.55 ± 0.118 &mgr;mol·L−1). Players who played between 13 and 25 minutes per game showed the highest values of TT (22.8 ± 6.9 nmol·L−1) and TT/C (47.1 ± 21.2). March and April showed the most catabolic or stressed hormonal state (low TT/C values and high ones of cortisol) and that is necessary to take into account according to PT (>25-minute per game) and specific playing position. Monitoring plasma TT and cortisol is recommended to prevent excessive stress caused by professional basketball season requirements.

Effectiveness of Oral and Topical Hydrogen for Sports-Related Soft Tissue Injuries

Abstract Background: Because hydrogen therapy has been found beneficial for the treatment of inflammation, ischemia-reperfusion injury, and oxidative stress in humans, it seems useful to evaluate the effects of exogenously administered hydrogen as an element in the immediate management of sports-related soft tissue injuries. The main aim of this pilot study was to examine the effects of 2-week administration of hydrogen on the biochemical markers of inflammation and functional recovery in male professional athletes after acute soft tissue injury. Method: During the 2013 season (from March to May), 36 professional athletes were recruited as participants and examined by a certified sports medicine specialist in the first 24 hours after an injury was sustained. Subjects were allocated to 3 randomly assigned trials in a single-blind design. Those in the control group received a traditional treatment protocol for soft tissue injury. Subjects in the first experimental group followed the same procedures as the control group but with additional administration throughout the study of oral hydrogen-rich tablets (2 g per day). Subjects in the second experimental group also followed the procedures of the control group, with additional administration throughout the study of both oral hydrogen-rich tablets (2 g per day) and topical hydrogen-rich packs (6 times per day for 20 minutes). Participants were evaluated at the time of the injury report and at 7 and 14 days after baseline testing. Results: Oral and topical hydrogen intervention was found to augment plasma viscosity decrease as compared with the control group (P = 0.04). Differences were found for range-of-motion recovery between the 3 groups; oral and topical hydrogen intervention resulted in a faster return to normal joint range of motion for both flexion and extension of the injured limb as compared with the control intervention (P < 0.05). Conclusion: These preliminary results support the hypothesis that the addition of hydrogen to traditional treatment protocols is potentially effective in the treatment of soft tissue injuries in male professional athletes. Trial identification: Clinicaltrials.gov number NCT01759498.