Acute cardiovascular, respiratory and metabolic effects of intra-repetition rest method and traditional sprint interval training

The aim of this thesis was to develop a novel Sprint Interval Training protocol (SIT) that achieves a higher peak oxygen uptake (VO2peak) response and longer time spent at a high percentage of maximal oxygen uptake (%VO2max) values and higher peak power output (PPO) values by splitting repetitions into clusters. Twelve male trained athletes participated (age: 19.58±1.44 years; height: 176±473 cm; weight: 65.9±5.68 kg; VO2max: 53.2±6.05 ml∙kg⁻1∙min⁻1) in this study. Firstly, participants were familiarised with the testing protocol. During their second visit to the laboratory participants performed an exhaustive graded test protocol in order to VO2max test. During visits 3 to 5 and in a randomised order, participants performed SIT30 (4 × (30-s work-bout (w) + 240-s recovery (r))), SIT15 (4 × (15-s w + 15-s w + 15-s w + 225-s r)) and a SIT10 (4 × (10-s w + 10-s r + 10-s w + 10-s r + 10-s w + 220-s r)) training protocol using a Wingate type exercise against 7.5% of body mass. Blood lactate responses were obtained before the start of the SIT protocols and during minute one, three and five post completion. PPO values (SIT30=697±70.9 watt, SIT15=732±63.1 watt, SIT10=752±75 watt; SIT30 vs. SIT15: p=0.001, SIT30 vs. SIT10: p=0.001 and SIT15 vs. SIT10: p=0.084), VO2peak response (SIT30=46.5±6.55 ml∙kg⁻1∙min⁻1, SIT15=51.9±4.78 ml∙kg⁻1∙min⁻1, SIT10=50.9±5.63 ml∙kg⁻1∙min⁻1; SIT30 vs. SIT10: p=0.012, SIT30 vs. SIT15: p=0.039 and SIT15 vs. SIT10: p=0.622) and time spent at ≥80% of VO2max (SIT30=27.9±28.4 seconds, SIT15=76.6±36.8 seconds, SIT10: 62.9±46.1 seconds; SIT30 vs. SIT15: p=0.008, SIT30 vs. SIT10: p=0.013 and SIT15 vs. SIT10: p=0.408) obtained through the SIT15 and SIT10 protocols were statistically significantly higher and longer respectively than those obtained from the SIT30 protocol. The SIT10 and SIT15 protocol using the clustering method may therefore offer a more advantageous training application in triggering VO2max adaptations.