Search Results

Purpose: To investigate the effects of a training camp with heat and/or hypoxia sessions on hematological and thermoregulatory adaptations. Methods: Fifty-six elite male rugby players completed a 2-week training camp with 5 endurance and 5 repeated-sprint sessions, rugby practice, and resistance training. Players were separated into 4 groups: CAMP trained in temperate conditions at sea level, HEAT performed the endurance sessions in the heat, ALTI slept and performed the repeated sprints at altitude, and H + A was a combination of the heat and altitude groups. Results: Blood volume across all groups increased by 140 mL (95%CI, 42–237; P = .006) and plasma volume by 97 mL (95%CI 28–167; P = .007) following the training camp. Plasma volume was 6.3% (0.3% to 12.4%) higher in HEAT than ALTI (P = .034) and slightly higher in HEAT than H + A (5.6% [−0.3% to 11.7%]; P = .076). Changes in hemoglobin mass were not significant (P = .176), despite a ∼1.2% increase in ALTI and H + A and a ∼0.7% decrease in CAMP and HEAT. Peak rectal temperature was lower during a postcamp heat-response test in HEAT (0.3 °C [0.1–0.5]; P = .010) and H + A (0.3 °C [0.1–0.6]; P = .005). Oxygen saturation upon waking was lower in ALTI (3% [2% to 5%]; P < .001) and H + A (4% [3% to 6%]; P < .001) than CAMP and HEAT. Conclusion: Although blood and plasma volume increased following the camp, sleeping at altitude impeded the increase when training in the heat and only marginally increased hemoglobin mass. Heat training induced adaptations commensurate with partial heat acclimation; however, combining heat training and altitude training and confinement during a training camp did not confer concomitant hematological adaptations.

Purpose: Preconditioning strategies are considered opportunities to optimize performance on competition day. Although investigations conducted in rugby players on the effects of a morning preconditioning session have been done, additional work is warranted. The aim of this study was to monitor changes in physical and psychophysiological indicators among international Rugby-7s players after a priming exercise. Methods: In a randomized crossover design, 14 under-18 international Rugby-7s players completed, at 8:00 AM, a preconditioning session consisting of a warm-up followed by small-sided games, accelerations, and 2 × 50-m maximal sprints (Experimental), or no preloading session (Control). After a 2-h break, the players performed a set of six 30-m sprints and a Rugby-7s match. Recovery–stress state and salivary stress-marker levels were assessed before the preloading session (Pre), immediately after the preloading session (Post 1), before the testing session (Post 2), and after the testing session (Post 3). Results: Experimental–Control differences in performance across a repeated-sprint test consisting of six 30-m sprints were very likely trivial (+0.2, ±0.7%, 3/97/1%). During the match, the total distance covered and the frequency of decelerations were possibly lower (small) in Experimental compared with Control. Differences observed in the other parameters were unclear or possibly trivial. At Post 2, the perceived recovery–stress state was improved (small difference) in Experimental compared with Control. No difference in salivary cortisol response was observed, while the preconditioning session induced a higher stimulation of salivary testosterone and α-amylase. Conclusions: The players’ ability to repeat sprints and physical activity in match play did not improve, but their psychophysiological state was positively affected after the present preconditioning session.

Purpose: To investigate whether including heat and altitude exposures during an elite team-sport training camp induces similar or greater performance benefits. Methods: The study assessed 56 elite male rugby players for maximal oxygen uptake, repeated-sprint cycling, and Yo-Yo intermittent recovery level 2 (Yo-Yo) before and after a 2-week training camp, which included 5 endurance and 5 repeated-sprint cycling sessions in addition to daily rugby training. Players were separated into 4 groups: (1) control (all sessions in temperate conditions at sea level), (2) heat training (endurance sessions in the heat), (3) altitude (repeated-sprint sessions and sleeping in hypoxia), and (4) combined heat and altitude (endurance in the heat, repeated sprints, and sleeping in hypoxia). Results: Training increased maximal oxygen uptake (4% [10%], P = .017), maximal aerobic power (9% [8%], P < .001), and repeated-sprint peak (5% [10%], P = .004) and average power (12% [14%], P < .001) independent of training conditions. Yo-Yo distance increased (16% [17%], P < .001) but not in the altitude group (P = .562). Training in heat lowered core temperature and increased sweat rate during a heat-response test (P < .05). Conclusion: A 2-week intensified training camp improved maximal oxygen uptake, repeated-sprint ability, and aerobic performance in elite rugby players. Adding heat and/or altitude did not further enhance physical performance, and altitude appears to have been detrimental to improving Yo-Yo.

Objectives: Repeated-sprint training in hypoxia (RSH) is an effective way of improving physical performance compared with similar training in normoxia. RSH efficiency relies on hypoxia severity, but also on the oxidative–glycolytic balance determined by both sprint duration and exercise-to-rest ratio. This study investigated the effect of 2 types of RSH sessions during a classic altitude camp in world-class female rugby sevens players. Methods: Sixteen players performed 5 RSH sessions on a cycle ergometer (simulated altitude: 3000 m above sea level [asl]) during a 3-week natural altitude camp (1850 m asl). Players were assigned to 2 different protocols with either a high (RSH_1:3, sprint duration: 8–10 s; exercise-to-rest ratios: 1:2–1:3; n = 7) or a low exercise-to-rest ratio (RSH_1:5, sprint duration: 5–15 s; exercise-to-rest ratios: 1:2–1:5; n = 9). Repeated-sprint performances (maximal and mean power outputs [PPO_max, and PPO_mean]) were measured before and after the intervention, along with physiological responses. Results: PPO_max (962 [100] to 1020 [143] W, P = .008, Cohen d = 0.47) and PPO_mean (733 [71] to 773 [91] W, P = .008, d = 0.50) increased from before to after. A significant interaction effect (P = .048, d = 0.50) was observed for PPO_mean, with a larger increase observed in RSH_1:3 (P = .003). No interaction effects were observed (P > .05) for the other variables. Conclusion: A classic altitude camp with 5 RSH sessions superimposed on rugby-sevens-specific training led to an improved repeated-sprint performance, suggesting that RSH effects are not blunted by prolonged hypoxic exposure. Interestingly, using a higher exercise-to-rest ratio during RSH appears to be more effective than when applying a lower exercise-to-rest ratio.