Effects of endurance training on muscle adaptations in males.

Group 1: low-intensity high-volume exercise. Participants will train 3 to 4 times per week throughout the 8-week period. Each exercise session will consist of a continuous cycling bout at an intensity of 90% of the first lactate threshold (WLT1) on a stationary bike for a length of 60 to 150 min. Each training session will be performed at the Exercise Physiology laboratory at Footscray Park Campus (Victoria University). The intensity is selected for the exercise to be continuous without requiring high effort, and the duration of the bout is selected based on the usual session duration done by endurance athletes at low intensity and is progressively increased to a maximum of 150 min to stimulate training adaptations. Group 2: high-intensity low-volume exercise. Participants will train 3 to 4 times per week throughout the 8-week period. Each exercise session will consist of an interval session with 30-seconds all-out sprints at a maximum intensity on a stationary bike (load imposed in the bike corresponds to 0.075 kg/kg body mass, this is derived from the Wingate test), performing a total of 4 to 10 sprints. Rest interval between sprints will be 4 minutes at a very low intensity (50 W). Each training session will be performed at the Exercise Physiology laboratory at Footscray Park Campus (Victoria University). The intensity is based on previous literature performing 30-seconds all-out sprints, and the number of sprints performed in previous studies varies between 4 and 10, so to stimulate training adaptations the number of sprints performed in each session is progressively increased. Both training groups are matched in the training load fold increase throughout the training period (e.g., both groups increase 2.5 times their weekly load from week 1 to week 8). Progression of the training is as follows: Week 1 (W1) will represent 100% of the training load; Week 2 training load will be the same as W1 + 25% of the load (in minutes for Group 1, and in sprints for Group 2); Week 3 will also be W1 + 50% of the load; this same pattern will be followed for Week 4 (W1 + 75 %), Week 6 (W1 + 100 %), Week 7 (W1 + 125 %), and Week 8 (W1 + 150 %). Only Week 5 will be different, as it will be like Week 3 (W1 + 50 %) to allow the training to follow a traditional periodised structure. All training sessions will be supervised by an experienced sport scientist.