You are looking at 41 - 50 of 5,325 items for :

  • Physical Education and Coaching x
  • Sport and Exercise Science/Kinesiology x
  • All content x
Clear All
Restricted access

Thomas I. Gee, Paul Harsley, and Daniel C. Bishop

Purpose: This study investigated the effects of complex-paired and reverse-contrast 10-week training programs on sprint, power, and change-of-direction speed performance of elite academy soccer players. Methods: Seventeen elite academy soccer players each performed assessments of the 10- and 40-m sprint, Abalakov vertical jump, seated medicine-ball throw, and Arrowhead change-of-direction speed test, both prior to and after a twice-weekly 10-week resistance-training program. The participants were randomly split into 2 groups; the complex-paired training group (CPT, n = 9) performed 4 different complex pairs (heavy-resistance exercises paired with plyometric and Olympic lifting–style exercises), with each pair being interspersed with an 8-minute recovery period in line with recommended guidelines. The comparative group—the reverse-contrast training group (RCT, n = 8)—performed the same exercises; however, all of the plyometric and Olympic lifting exercises preceded the heavy-resistance exercises. Results: Both groups achieved postintervention increases in the seated medicine-ball throw test (CPT +1.8% and RCT +1.6%, P < .05), whereas VJ performance improved only in the CPT group (+3.4%, P = .003). No significant improvements were observed in either the 10- and the 40-m sprint or Arrowhead change-of-direction speed test for either group. Conclusions: The CPT experienced a small but significant within-group improvement in jump performance. However, no significant between-groups differences were observed in any of the testing variables postintervention. Subsequently, for academy soccer athletes, the CPT approach did not produce meaningful benefits to performance compared with a more time-efficient reverse-contrast approach.

Restricted access

Andrew M. Holwerda, Jorn Trommelen, Imre W.K. Kouw, Joan M. Senden, Joy P.B. Goessens, Janneau van Kranenburg, Annemie P. Gijsen, Lex B. Verdijk, and Luc J.C. van Loon

Protein ingestion and exercise stimulate myofibrillar protein synthesis rates. When combined, exercise further increases the postprandial rise in myofibrillar protein synthesis rates. It remains unclear whether protein ingestion with or without exercise also stimulates muscle connective tissue protein synthesis rates. The authors assessed the impact of presleep protein ingestion on overnight muscle connective tissue protein synthesis rates at rest and during recovery from resistance-type exercise in older men. Thirty-six healthy, older men were randomly assigned to ingest 40 g intrinsically L-[1-13C]-phenylalanine and L-[1-13C]-leucine-labeled casein protein (PRO, n = 12) or a nonprotein placebo (PLA, n = 12) before going to sleep. A third group performed a single bout of resistance-type exercise in the evening before ingesting 40 g intrinsically-labeled casein protein prior to sleep (EX+PRO, n = 12). Continuous intravenous infusions of L-[ring-2H5]-phenylalanine and L-[1-13C]-leucine were applied with blood and muscle tissue samples collected throughout overnight sleep. Presleep protein ingestion did not increase muscle connective tissue protein synthesis rates (0.049 ± 0.013 vs. 0.060 ± 0.024%/hr in PLA and PRO, respectively; p = .73). Exercise plus protein ingestion resulted in greater overnight muscle connective tissue protein synthesis rates (0.095 ± 0.022%/hr) when compared with PLA and PRO (p < .01). Exercise increased the incorporation of dietary protein-derived amino acids into muscle connective tissue protein (0.036 ± 0.013 vs. 0.054 ± 0.009 mole percent excess in PRO vs. EX+PRO, respectively; p < .01). In conclusion, resistance-type exercise plus presleep protein ingestion increases overnight muscle connective tissue protein synthesis rates in older men. Exercise enhances the utilization of dietary protein-derived amino acids as precursors for de novo muscle connective tissue protein synthesis during overnight sleep.

Restricted access

Nick Dobbin, Anthony Atherton, and Colin Hill

Purpose: To determine if small-sided games (SSGs) could be designed to target specific task loads using the National Aeronautics and Space Administration task load index as well as reporting the influence of the physical and technical demands. Methods: Using a within-session, repeated-measures design, 26 junior rugby league players completed 5 SSGs focused on physical, technical, temporal, cognitive, and frustration task loads. National Aeronautics and Space Administration task load index responses were evaluated after each game; the physical demands were recorded using microtechnology; and skill involvement recorded using video analysis. Results: In each SSG, the task load emphasized (eg, physical load/physical game) emerged with a higher score than the other loads and SSGs. The physical demands were lowest during the physical game (effect size = −3.11 to 3.50) and elicited greater defensive involvements (effect size = 0.12 to 3.19). The highest physical demands and attacking involvements were observed during the temporal game. Lower intensity activities were generally negatively associated with physical, performance, temporal, and total load (η 2 = −.07 to −.43) but positively associated with technical, effort, cognitive, and frustration (η 2 = .01 to .33). Distance covered in total and at higher speeds was positively associated with physical, effort, performance, total load (η 2 = .18 to .65), and negatively associated with technical, frustration, and cognitive load (η 2 = −.10 to −.36). Attacking and defensive involvements generally increased the respective task loads (η 2 = .03 to .41). Conclusion: Coaches and sport scientists can design SSGs specifically targeted at subjective task loads in a sport-specific manner and through manipulation of the physical and technical demands.

Restricted access

Irineu Loturco, Lucas A. Pereira, Tomás T. Freitas, Chris Bishop, Fernando Pareja-Blanco, and Michael R. McGuigan

Purpose: To test the relationships between maximum and relative strength (MS and RS), absolute and relative peak force (PF and RPF), and strength deficit (SDef), with sprint and jump performance, and to compare these mechanical variables between elite sprinters and professional rugby union players. Methods: Thirty-five male rugby union players and 30 male sprinters performed vertical jumps, 30-m sprint, and half-squat 1-repetition maximum (1RM), where these force-related parameters were collected. Pearson correlation coefficients were used to test the relationships between the variables. An independent t test and magnitude-based inferences compared the mechanical variables between sprinters and rugby players. Results: Almost certain significant differences were observed for jump and sprint performance between groups (P < .0001). The rugby union players demonstrated a likely significant higher MS (P = .03) but a very likely lower RS (P = .007) than the sprinters. No significant differences were observed for PF between them. The sprinters exhibited an almost certain significant higher RPF than the rugby players (P < .0001). Furthermore, the rugby players demonstrated almost certain to likely significant higher SDef from 40% to 70% 1RM (P < .05) compared with the sprinters. Overall, all strength-derived parameters were significantly related to functional performance. Conclusions: Elite sprinters present higher levels of RS and RPF, lower levels of SDef, and better sprint and jump performance than professional rugby players. Relative strength-derived values (RS and RPF) and SDef are significantly associated with speed–power measures and may be used as effective and practical indicators of athletic performance.

Open access

Ralph Beneke and Renate M. Leithäuser

Restricted access

Roberto Baldassarre, Cristian Ieno, Marco Bonifazi, and Maria Francesca Piacentini

Purpose: The sensation of fatigue experienced at a certain point of the race is an important factor in the regulation of pacing. The rating of perceived exertion (RPE) is considered one of the main mediators utilized by athletes to modify pacing. The aim was to analyze the relationship between pacing and RPE of elite open water swimmers during national indoor pool championships. Methods: A total of 17 elite open water swimmers (males, n = 9; females, n = 8) agreed to provide RPE every 500 m during the finals of the national championships 5-km indoor pool race. Time splits, stroke rate, and RPE were collected every 500 m. The Hazard score was calculated by multiplying the momentary RPE by the remaining fraction of the race. Athletes were placed in one of two categories: medalists or nonmedalists. For all variables, separate mixed analysis of variances (P ≤ .05) with repeated measures were used considering the splits (ie, every 500 m) as within-subjects factor and the groups (ie, medalists and nonmedalists) as between-subjects factor. Results: Average swimming speed showed a significant main effect for split for both males and females (P < .001). A significant interaction was observed between average swimming speed and groups for females (P = .032). RPE increased in both groups (P < .001) with no difference observed between groups. However, the female nonmedalists showed a disproportionate nonlinear increase in RPE (5.20 [2.31]) halfway through the event that corresponded to the point where they started significantly decreasing speed. Conclusions: The results of the present study show different pacing strategies adopted by medalists and nonmedalists despite a similar RPE.

Open access

Iñigo Mujika

Restricted access

Mohamed Romdhani, Nizar Souissi, Imen Moussa-Chamari, Yassine Chaabouni, Kacem Mahdouani, Zouheir Sahnoun, Tarak Driss, Karim Chamari, and Omar Hammouda

Purpose: To compare the effect of a 20-minute nap opportunity (N20), a moderate dose of caffeine (CAF; 5 mg·kg−1), or a moderate dose of caffeine before N20 (CAF+N) as possible countermeasures to the decreased performance and the partial sleep deprivation–induced muscle damage. Methods: Nine male, highly trained judokas were randomly assigned to either baseline normal sleep night, placebo, N20, CAF, or CAF+N. Test sessions included the running-based anaerobic sprint test, from which the maximum (P max), mean (P mean), and minimum (P min) powers were calculated. Biomarkers of muscle, hepatic, and cardiac damage and of enzymatic and nonenzymatic antioxidants were measured at rest and after the exercise. Results: N20 increased P max compared with placebo (P < .01, d = 0.75). CAF+N increased P max (P < .001, d = 1.5; d = 0.94), P min (P < .001, d = 2.79; d = 2.6), and P mean (P < .001, d = 1.93; d = 1.79) compared with placebo and CAF, respectively. Postexercise creatine kinase increased whenever caffeine was added, that is, after CAF (P < .001, d = 1.19) and CAF+N (P < .001, d = 1.36). Postexercise uric acid increased whenever participants napped, that is, after N20 (P < .001, d = 2.19) and CAF+N (P < .001, d = 2.50) and decreased after CAF (P < .001, d = 2.96). Conclusion: Napping improved repeated-sprint performance and antioxidant defense after partial sleep deprivation. Contrarily, caffeine increased muscle damage without improving performance. For sleep-deprived athletes, caffeine before a short nap opportunity would be more beneficial for repeated sprint performance than each treatment alone.

Restricted access

Naroa Etxebarria, Jackson Wright, Hamish Jeacocke, Cristian Mesquida, and David B. Pyne

Negative or evenly paced racing strategies often lead to more favorable performance outcomes for endurance athletes. However, casual inspection of race split times and observational studies both indicate that elite triathletes competing in Olympic-distance triathlon typically implement a positive pacing strategy during the last of the 3 disciplines, the 10-km run. To address this apparent contradiction, the authors examined data from 14 International Triathlon Union elite races over 3 consecutive years involving a total of 725 male athletes. Analyses of race results confirm that triathletes typically implement a positive running pace strategy, running the first lap of the standard 4-lap circuit substantially faster than laps 2 (∼7%), 3 (∼9%), and 4 (∼12%). Interestingly, mean running pace in lap 1 had a substantially lower correlation with 10-km run time (r = .82) than both laps 2 and 3. Overall triathlon race performance (ranking) was best associated with run performance (r = .82) compared with the swim and cycle sections. Lower variability in race pace during the 10-km run was also reflective of more successful run times. Given that overall race outcome is mainly explained by the 10-km run performance, with top run performances associated with a more evenly paced strategy, triathletes (and their coaches) should reevaluate their pacing strategy during the run section.

Restricted access

Kate M. Luckin-Baldwin, Claire E. Badenhorst, Ashley J. Cripps, Grant J. Landers, Robert J. Merrells, Max K. Bulsara, and Gerard F. Hoyne

Purpose: The completion of concurrent strength and endurance training can improve exercise economy in cyclists and runners; however, the efficacy of strength training (ST) implementation to improve economy in long-distance (LD) triathletes has not yet been investigated. The purpose of this study was to investigate physiological outcomes in LD triathletes when ST was completed concurrently to endurance training. Methods: A total of 25 LD triathletes were randomly assigned to either 26 weeks of concurrent endurance and ST (n = 14) or endurance training only (n = 11). The ST program progressed from moderate (8–12 repetitions, ≤75% of 1-repetition maximum, weeks 0–12) to heavy loads (1–6 repetitions, ≥85% of 1-repetition maximum, weeks 14–26). Physiological and performance indicators (cycling and running economy, swim time, blood lactate, and heart rate) were measured during a simulated triathlon (1500-m swim, 60-min cycle, and 20-min run) at weeks 0, 14, and 26. Maximal strength and anthropometric measures (skinfolds and body mass) were also collected at these points. Results: The endurance strength group significantly improved maximal strength measures at weeks 14 and 26 (P < .05), cycling economy from weeks 0 to 14 (P < .05), and running economy from weeks 14 to 26 (P < .05) with no change in body mass (P > .05). The endurance-only group did not significantly improve any economy measures. Conclusions: The addition of progressive load ST to LD triathletes’ training programs can significantly improve running and cycling economy without an increase in body mass.