DETERMINATION OF OPTIMAL LOADS FOR SPRINT INTERVAL EXERCISES: AN INVESTIGATION ON ENERGY EXPENDITURE AND LIPID OXIDATION
Project no. 681 · Status: Kapanmış · 2017
Summary
Traditional sprint interval exercises (SIT1) include all-out Wingate-type loads using 7.5% of body mass (BM). However, in these exercises “sprint” feature is lost depending on the dramatic drop in pedal revolution cadence (rpm) in subsequent loads after the first repetition. The aim of this study is, as an alternative to the currently popular SIT1, to evaluate the potential impact of new SIT modalities at higher levels of pedal revolution cadence on improving endurance. Seven non-cyclist and recreational physical activity (3-5 days/week) male subjects volunteered to participate in this study. Following familiarization sessions, peak oxygen uptake (VO2peak) of the subjects were determined. Subsequently, five new sprint intervals (SIT2; all-out with 5% of BM, SIT3; constant 120 rpm using with a resistance equivalent to ~200% of VO2peak, SIT4; average cadence values of the 30-s effort were above 120 rpm, all-out effort using %7,5 of BM, SIT5;last 5-s average cadence of the 30-second effort were above 120 rpm, all-out effort using %5 of BM and SIT6; constant 120 rpm using with all-out isokinetic model) were applied as an alternative to SIT1. All sessions 6×30-sec;1:8 load/recovery ratio were used. Respiratory gases were also recorded continuously during all sessions and after 3-hour. Finally, during the sessions, the maximum lactate responses were measured, while the post-session 2-hour blood lactate recovery kinetics was measured. Parametric data were assessed using the repeated measures analysis method and LSD as post-hoc, and non-parametric data were assessed using the K-Related Samples/Friedman and Wilcoxon test as post-hoc. The highest cadence average was determined at SIT5 with 139 rpm (p=0.001). Therefore, the SIT5 obtained the highest ? blood lactate response compared to SIT1, SIT2 and SIT3 (19.9 mmol·L-1; p<0.05). The blood lactate responses at obtained 120 minute of the SIT5 (2.3 mmol·L-1) were higher than all other modalities (p<0.05). Besides, RER values of the SIT5 returned to later baseline conditions compared to the SIT1 and SIT4, which the higher cadences could not be preserved (p<0.05). As a result, it was determined that the SIT5 endurance potential could be higher due to high cadences protect and high lactate responses. Key words: High intensity interval training; anaerobic endurance; aerobic endurance; cadence; angular velocity; muscular fibril; neural adaptations; recovery oxygen after exercise; respiratory exchange rate; lactate.