AbstractsBiology & Animal Science

Repeated-sprint ability (RSA), power and strength are regarded as fundamental physical attributes for team-sport athletes. Investigations of concurrently training these fitness qualities, particularly in well-trained female team-sport athletes are scarce. The primary purpose of this thesis was the improvement of team-sport performance in female athletes through concurrent resistance (RT) and RSA training, concentrating on acute and chronic training structure. With recent interest in inflammatory cytokines in sports science, the cytokine response to concurrent exercise was also investigated with the aim of effectively measuring internal training load. The mechanism of action of interleukin (IL)-6, the most commonly researched cytokine in sports science, was also investigated. Chapters 4 and 5 measured performance and magnitude of change in inflammatory cytokines and endocrine hormones to single mode or concurrent RT (6 × 6 sets of back squat exercise at 80 % 1-repetition maximum, sets separated by 3 min rest 2) and RSA (4 × 6 sets of 20 m maximal shuttle sprints, sets separated by 3 min rest) exercise of different intra-session exercise order (exercise modes separated by 15 min rest). It was found that exercise intensity and duration were important factors in the exercise induced cytokine and endocrine hormone response to exercise as significant alterations in these bio-markers were only seen following concurrent exercise (Chapter 5) and not during single-mode RT and RSA exercise (Chapter 4). There did not appear to be evidence of acute interference or residual fatigue present during the concurrent exercise protocol as intra-session exercise order did not affect maximal squat or sprint performance, or rating of perceived exertion in response to either mode of exercise. Exercise order showed minor differences in a small number of bio-markers. Chapters 6 and 7 investigated the effects of 4 weeks of concurrent RT and RSA training, performed either on the same day (SDT: in a single session, 3 sessions per week) or alternating days (ADT: 6 sessions per week, each separated by 24h) on performance and systemic and skeletal muscle physiological responses to an acute concurrent RT/RSA protocol (protocol identical to RT:RSA exercise performed in Chapter 5). Both training structures were found to significantly increase RSA total time, sprinting, jumping and maximal strength performance. Interestingly, training structure (SDT or ADT) had no significant effect on the magnitude of these increases despite large differences in rest periods (15 minutes vs. 24 hours) between the exercise modes perhaps suggesting that the volume of the acute stimulus is less important than the total volume of training. The acute concurrent RT and RSA protocol (both pre- and post-training) significantly altered systemic and local cytokines, hormones and signalling proteins within 180 minutes of the recovery period. However, training appeared to have no effect on the majority of these responses with only serum cortisol and plasma glucose…