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This study aimed to determine whether caffeine gum influenced perceptual-cognitive and physical performance during the extra-time period of simulated soccer match-play. Semiprofessional male soccer players (n = 12, age: 22 ± 3 years, stature: 1.78 ± 0.06 m, mass: 75 ± 9 kg) performed 120-min soccer-specific exercise on two occasions. In a triple-blind, randomized, crossover design, players chewed caffeinated (200 mg; caffeine) or control (0 mg; placebo) gum for 5 min following 90 min of soccer-specific exercise. Perceptual-cognitive skills (i.e., passing accuracy, reaction time, composure, and adaptability) were assessed using a soccer-specific virtual reality simulator, collected pre- and posttrial. Neuromuscular performance (reactive-strength index, vertical jump height, absolute and relative peak power output, and negative vertical displacement) and sprint performance (15 and 30 m) were measured at pretrial, half-time, 90 min, and posttrial. Caffeine gum attenuated declines in reaction time (pre: 90.8 ± 0.8 AU to post: 90.7 ± 0.8 AU) by a further 4.2% than placebo (pre: 92.1 ± 0.8 AU to post: 88.2 ± 0.8 AU; p <.01). Caffeine gum reduced composure by 4.7% (pre: 69.1 ± 0.8 AU to post: 65.9 ± 0.8 AU) versus placebo (pre: 68.8 ± 0.8 AU to post: 68.3 ± 0.8 AU; p <.01). Caffeine gum did not influence any other variables (p >.05). Where caffeine gum is consumed by players prior to extra-time, reaction time increases but composure may be compromised, and neuromuscular and sprint performance remain unchanged. Future work should assess caffeine gum mixes with substances like L-theanine that promote a relaxed state under stressful conditions. [ABSTRACT FROM AUTHOR]

Carbohydrates are critical for high‐intensity exercise performance. However, the effects of carbohydrate supplementation on muscle metabolism and performance during short‐duration high‐intensity intermittent exercise remain inadequately explored. Our aim was to address this aspect in a randomized, counterbalanced, double‐blinded crossover design. Eleven moderately‐to‐well‐trained males performed high‐intensity intermittent cycling receiving carbohydrate (CHO, ~55 g/h) or placebo (PLA) fluid supplementation. Three exercise periods (EX1‐EX3) were completed comprising 10 × 45 s at ~105% Wmax interspersed with 135 s rest between bouts and ~20 min between periods. Repeated sprint ability (5 × 6 s sprints with 24 s recovery) was assessed at baseline and after each period. Thigh muscle biopsies were obtained at baseline and before and after EX3 to determine whole‐muscle and fiber‐type‐specific glycogen depletion. No differences were found in muscle glycogen degradation at the whole‐muscle (p = 0.683) or fiber‐type‐specific level (p = 0.763–0.854) with similar post‐exercise whole‐muscle glycogen concentrations (146 ± 20 and 122 ± 15 mmol·kg−1 dw in CHO and PLA, respectively). Repeated sprint ability declined by ~9% after EX3 with no between‐condition differences (p = 0.971) and no overall differences in ratings of perceived exertion (p = 0.550). This was despite distinctions in blood glucose concentrations throughout exercise, reaching post‐exercise levels of 5.3 ± 0.2 and 4.1 ± 0.2 mmol·L−1 (p < 0.001) in CHO and PLA, respectively, accompanied by fivefold higher plasma insulin levels in CHO (p < 0.001). In conclusion, we observed no effects of carbohydrate ingestion on net muscle glycogen breakdown or sprint performance during short‐duration high‐intensity intermittent exercise despite elevated blood glucose and insulin levels. These results therefore question the efficacy of carbohydrate supplementation strategies in high‐intensity intermittent sports. [ABSTRACT FROM AUTHOR]

Background/Objectives: The aim of this study was to evaluate the effects of lifelong team handball/football training on regional bone health and body composition in elderly women. Methods: Seventeen elderly women team handball/football players (65.9 ± 5.7 years) and twenty-one untrained age-matched women (controls) (67.7 ± 5.1 years) participated. Whole-body and regional dual-energy X-ray absorptiometry scans of arms, legs, and lower spine (L1–L4) were performed. Results: We observed 8% and 9% higher bone mineral density (BMD) and bone mineral content (BMC), respectively, at the whole-body level and in the legs and 11.5% higher BMC in the legs in team handball/football players compared to untrained age-matched controls (p < 0.05). Higher total and leg lean body mass (p < 0.05), along with lower total body fat percentage (p < 0.05) and higher T- and Z-scores, markers of fragility risk fracture (0.294 ± 1.461 vs. −0.538 ± 1.031; 1.447 ± 1.278 vs. 0.724 ± 0.823, respectively), were also found in team handball/football players compared to controls (p < 0.05). No significant differences in nutritional habits were observed between groups. Conclusions: Our study suggest that the beneficial effects of lifetime handball/football practice on bone preservation in elderly women occur independently from nutritional intake, which emphasize the potential role of team sports in osteoporosis prevention. Future studies should focus on the cofounding factors and causative mechanisms mediated by team sport practice in osteoporosis prevention. [ABSTRACT FROM AUTHOR]

To investigate i) if a recreational futsal (RF) training session elicits post-exercise hypotension (PEH), ii) the impact of a 3-month RF intervention on PEH, and iii) the association between PEH in the early phase of the intervention with resting blood pressure (BP) chronic adaptions in men with treated hypertension. BP was measured before and after a RF training session every 5-min (total of 30-min) in the early (weeks 1–2) and the final phases (weeks 11–12) of a 3-month RF intervention, comprising 3 weekly one-hour sessions. Thirty-three men (48 ± 7 years; mean arterial pressure [MAP]: 96 ± 8 mmHg; BMI: 32.2 ± 4.9 kg/m2) participated. In the intervention early phase, systolic BP ([SBP]; −15.4 mmHg; 95% CI: −10.9, −16.8), diastolic BP ([DBP]; −5.4 mmHg; 95% CI: −7.8, −3.0), and MAP (−8.8 mmHg; 95% CI: −11.2, −6.4) significantly decreased 30-min post- compared to pre-training session (n = 33). In the intervention final phase (n = 24), SBP (−8.1 mmHg; 95% CI: −12.0, −3.9) and MAP (−3.0 mmHg; 95% CI: −5.4, −0.7) significantly decreased 30-min post- compared to pre-training session, but not DBP (−0.5 mmHg; 95% CI: −3.7, 2.7). PEH in the final phase was significantly inferior compared to the early phase. PEH in the early phase of the intervention was not consistently associated with chronic BP changes. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to examine the recovery kinetics (i.e., time-dependent changes) of performance-related variables between two 120-min male football games performed 3 d apart with and without carbohydrate supplementation. Methods: Twenty male players (20 ± 1 yr; body fat, 14.9% ± 5.1%; maximal oxygen consumption, 59.4 ± 3.7 mL⋅kg-1⋅min-1) participated in two 120-min football games (G1, G2) according to a randomized, two-trial, repeated-measures, crossover, double-blind design. Participants received carbohydrate/placebo supplements during recovery between games. Field activity was monitored during the games. Performance testing and blood sampling were performed before and at 90 and 120 min of each game. Muscle biopsies were collected at baseline and at 90 and 120 min of G1 and pre-G2. Results: Compared with G1, G2 was associated with reduced total distance (10,870 vs 10,685 m during 90 min and 3327 vs 3089 m during extra 30 min; P = 0.007-0.038), average (6.7 vs 6.2 km/h during extra 30-min game-play; P = 0.007) and maximal speed (32.2 vs 30.2 km/h during 90 min and 29.0 vs 27.9 km/h during extra 30 min; P < 0.05), accelerations/decelerations (P < 0.05), and mean heart rate (P < 0.05). Repeated sprint ability (P < 0.001), jumping (P < 0.05), and strength (P < 0.001) performance were compromised before and during G2. Muscle glycogen was not restored at G2 baseline (P = 0.005). Extended game-play reduced lymphocyte, erythrocyte counts, hematocrit, hemoglobin, reduced glutathione (P < 0.05) and increased delayed onset of muscle soreness, creatine kinase activity, blood glycerol, ammonia, and protein carbonyls (P < 0.05) before and during G2. Pax7+ (P = 0.004) and MyoD+ cells (P = 0.019) increased at baseline G2. Carbohydrate supplementation restored performance and glycogen, reduced glycerol and delayed onset of muscle soreness responses, and increased leukocyte counts and Pax7+ and MyoD+ cells. Conclusions: Results suggest that extended football games induce a prolonged recovery of performance, which may be facilitated by carbohydrate supplementation during a congested game fixture. [ABSTRACT FROM AUTHOR]

Purpose: We investigated whether 4 weeks of intensified training consisting of speed endurance training (SET) enhanced high-intensity exercise performance in youth national-team ice hockey players. Methods: Utilizing a randomized crossover design, we subjected 17 players to 4 weeks of SET, comprising 6 to 10 × 20 seconds at maximal effort (>95% maximum ice skating speed) with 120-second recovery performed 3 times weekly, or maintenance of regular training (control period). Before and after each period, players completed ice-hockey-specific tests on ice, including a Yo-Yo Intermittent Recovery Level 1 test, a 30-m sprint test, and an agility test. On a separate day, players were assessed for body composition with dual-energy X-ray absorptiometry and performed countermovement jump, maximal voluntary isometric knee extensor contraction, a 15-second maximal sprint test, and a submaximal and incremental test on a bike ergometer in which pulmonary oxygen consumption was determined. Results: Yo-Yo Intermittent Recovery Level 1 test performance increased (P <.001) by 14% (95% CI, 201–496 m) during the SET period. Maximal pulmonary oxygen consumption (P <.05) and time to exhaustion (P <.05) were 4.8% and 6.5% higher, respectively, after the SET period than before. Fat-free mass increased (P <.01) during the SET period by 1.7 kg (95% CI, 1.0–2.5), whereas fat mass remained unchanged. These effects were superior to the control period. Conclusions: These findings underpin the effectiveness of SET for improving on-ice high-intensity performance and highlight that elite ice hockey players can benefit from implementing SET. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare training load (TL) between practice and games across in-season microcycles in elite Danish male ice hockey. Methods: Practice sessions and game data were collected using a wearable 200-Hz accelerometer, heart rate (HR) recording, and rating of perceived exertion (RPE) throughout 23 practice sessions and 8 competitive games (n = 427 files) and examined in relation to the number of days before the game (game day minus). Results: Total accelerations, accelerations >2 m·s−2 (Acc2), total decelerations, decelerations less than −2 m·s−2 (Dec2), time >85% maximum heart rate (t85HRmax), Edwards TL, modified training impulse (TRIMPMOD), session-RPE, peak HR (HRpeak), and RPE were greater during competition than during practice (r =.19–.91; P <.05), whereas total accelerations per minute and total decelerations per minute were lower (r =.27–.36; P <.001). Acc2, t85HRmax, Edwards TL and TRIMPMOD, % t85HRmax, mean HR (HRmean), and RPE progressively decreased toward game day (r =.13–.63; P <.001). Positive correlations were found between Acc2, Dec2, Acc2 per minute, and Dec2 per minute during practice and during competition (r =.66–.84; P <.001). Conclusions: Evident within-week decreases in internal TL but not external TL were observed as the game day approached. Day-to-day variations were more pronounced in HR- and RPE-based parameters than accelerations and decelerations. Finally, the amount of intense accelerations and decelerations performed during practice was associated to the amount performed during competition, whereas physiological and perceptual demands showed no such relationship. [ABSTRACT FROM AUTHOR]

Ice hockey is an intense team sport characterized by repeated bursts of fast‐paced skating, rapid changes in speed and direction and frequent physical encounters. These are performed in on‐ice shifts of ~30–80 s interspersed with longer sequences of passive recovery, resulting in about 15–25 min on‐ice time per player. Nearly 50% of the distance is covered at high‐intensity skating speeds and with an accentuated intense activity pattern in forwards compared to defensemen. During ice hockey match‐play, both aerobic and anaerobic energy systems are significantly challenged, with the heart rate increasing toward maximum levels during each shift, and with great reliance on both glycolytic and phosphagen ATP provision. The high‐intensity activity pattern favors muscle glycogen as fuel, leading to pronounced reductions despite the relatively brief playing time, including severe depletion of a substantial proportion of individual fast‐ and slow‐twitch fibers. Player‐tracking suggests that the ability to perform high‐intensity skating is compromised in the final stages of a game, which is supported by post‐game reductions in repeated‐sprint ability. Muscle glycogen degradation, in particular in individual fibers, as well as potential dehydration and hyperthermia, may be prime candidates implicated in exacerbated fatigue during the final stages of a game, whereas multiple factors likely interact to impair exercise tolerance during each shift. This includes pronounced PCr degradation, with potential inadequate resynthesis in a proportion of fast‐twitch fibers in situations of repeated intense actions. Finally, the recovery pattern is inadequately described, but seems less long‐lasting than in other team sports. [ABSTRACT FROM AUTHOR]