This study determined the effect of repeated sprint training in hypoxia (RSH) in female athletes. Thirty-two college female athletes performed repeated cycling sprints of two sets of 10 × 7-s sprints with a 30-s rest between sprints twice per week for 4 weeks under either normoxic conditions (RSN group; FiO2, 20.9%; n = 16) or hypoxic conditions (RSH group; FiO2, 14.5%; n = 16). The repeated sprint ability (10 × 7-s sprints) and maximal oxygen uptake ( $$ \dot{\text{V}}{\text{O}}_{2\hbox{max} } $$ V ˙ O 2 max ) were determined before and after the training period. After training, when compared to pre-values, the mean power output was higher in all sprints during the repeated sprint test in the RSH group but only for the second half of the sprints in the RSN group (P ≤ 0.05). The percentage increases in peak and mean power output between before and after the training period were significantly greater in the RSH group than in the RSN group (peak power output, 5.0 ± 0.7% vs. 1.5 ± 0.9%, respectively; mean power output, 9.7 ± 0.9% vs. 6.0 ± 0.8%, respectively; P < 0.05). $$ \dot{\text{V}}{\text{O}}_{2\hbox{max} } $$ V ˙ O 2 max did not change significantly after the training period in either group. Four weeks of RSH further enhanced the peak and mean power output during repeated sprint test compared with RSN.

Purpose: The present study investigated the effects of three consecutive days of endurance training under conditions of low energy availability (LEA) on the muscle glycogen content, muscle damage markers, endocrine regulation, and endurance capacity in male runners. Methods: Seven male long-distance runners (19.9 ± 1.1 yr, 175.6 ± 4.7 cm, 61.4 ± 5.3 kg, maximal oxygen uptake [V˙O_2max]: 67.5 ± 4.3 mL·kg⁻¹·min⁻¹) completed two trials consisting of three consecutive days of endurance training under LEA (18.9 ± 1.9 kcal·kg FFM⁻¹·d⁻¹) or normal energy availability (NEA) (52.9 ± 5.0 kcal·kg FFM⁻¹·d⁻¹). The order of the two trials was randomized, with a 2-wk interval between trials. The endurance training consisted of 75 min of treadmill running at 70% of V˙O_2max. Muscle glycogen content, respiratory gas variables, and blood and urine variables were measured in the morning for three consecutive days of training (days 1–3) and on the following morning after training (day 4). As an indication of endurance capacity, time to exhaustion at 19.0 ± 0.8 km·h⁻¹ to elicit 90% of V˙O_2max was evaluated on day 4. Results: During the training period, body weight, fat-free mass, and skeletal muscle volume were significantly reduced in LEA (P = 0.02 for body weight and skeletal muscle volume, P = 0.01 for fat-free mass). Additionally, muscle glycogen content was significantly reduced in LEA (~30%, P < 0.001), with significantly lower values than those in NEA (P < 0.001). Time to exhaustion was not significantly different between the two trials (~20 min, P = 0.39). Conclusions: Three consecutive days of endurance training under LEA decreased muscle glycogen content with lowered body weight. However, endurance capacity was not significantly impaired.

Petition maximum (1RM) for nine exercises) in two trials, wearing either a CG or a normal garment (CON) for 24 h after exercise. Recovery of muscular strength, blood parameters, muscle soreness, and upper arm and thigh circumference were compared between the trials. Results Both trials showed decreases in maximal strength after the exercise (P < 0.05). However, the CG trial showed faster recovery of one-repetition maximum for the chest press from 3 to 8 h after exercise (P < 0.05). Recovery of maximal knee extension strength was also improved in the CG trial 24 h after exercise (P < 0.05). The CG trial was associated with lower muscle soreness and subjective fatigue scores the following morning (P < 0.05). The upper arm and thigh circumferences were significantly higher during the recovery period in the CON trial, whereas no change was observed in the CG trial. Blood lactate, insulin like growth factor-1, free testosterone, myoglobin, creatine kinase, interleukin 6, and interleukin 1 receptor antagonist concentrations for 24 h after exercise were similar in both trials. Conclusions Wearing a CG after resistance exercise facilitates the recovery of muscular strength. Recovery for upper body muscles significantly improved within 3–8 h after exercise. However, facilitation of recovery of lower limb muscles by wearing the CG took a longer time....

The present study examined the effects of wearing a lower-body compression garment (CG) after endurance exercise on recovery of physiological function. 18 males were divided into 2 experiments, the downhill running (n=10, DHR) experiments and the level running (n=8, LR) experiments. Subjects performed 30 min of DHR (gradient: − 10%) or LR (gradient: 0%) at 70% of ˙VO₂max with either wearing a CG (CG trial) or normal garment (CON trial) for 24 h after running. Changes in jump performance (counter movement jump; CMJ, rebound jump; RJ, drop jump; DJ), subjective feelings, circumferences of leg, and blood variables (creatine kinase, myoglobin, interleukin-6, high-sensitivity C-reactive protein) were evaluated before exercise, immediately after exercise, 1, 3 and 24 h following exercise. Running economy was evaluated at 24 h following exercise. CMJ height and RJ index were significantly higher in the CG trial than in the CON trial 24 h after running (P<0.05). Although changes in muscle soreness and blood variables were significantly greater in the DHR experiment than in the LR experiment, there was no significant difference between the trials in either experiment. Wearing a CG following endurance exercise facilitated recovery of jump performance under situations with severe exercise-induced muscle damage.