Combined effects of very short all out efforts during sprint and resistance training on physical and physiological adaptations after 2 weeks of training

PurposeThe aim of this study was to compare the combined effects of resistance and sprint training, with very short efforts (5s), on aerobic and anaerobic performances, and cardiometabolic health-related parameters in young healthy adults.MethodsThirty young physically active individuals were randomly allocated into four groups: resistance training (RTG), sprint interval training (SITG), concurrent training (CTG), and control (CONG). Participants trained 3 days/week for 2 weeks in the high-intensity interventions that consisted of 6-12 all out efforts of 5s separated by 24s of recovery, totalizing similar to 13min per session, with 48-72h of recovery between sessions. Body composition, vertical jump, lower body strength, aerobic and anaerobic performances, heart rate variability (HRV), and redox status were evaluated before and after training. Total work (TW), rating of perceived exertion (CR-10 RPE) and mean HR (HRmean) were monitored during sessions. Incidental physical activity (PA), dietary intake and perceived stress were also controlled.ResultsMaximum oxygen consumption (VO2max) significantly increased in SITG and CTG (P<0.05). Lower body strength improved in RTG and CTG (P<0.05), while countermovement jump (CMJ) was improved in RTG (P=0.04) only. Redox status improved after all interventions (P<0.05). No differences were found in TW, PA, dietary intake, and psychological stress between groups (P>0.05).ConclusionsRT and SIT protocols with very short all out efforts, either performed in isolation, or combined, demonstrated improvement in several physical fitness- and health-related parameters. However, CT was the most efficient exercise intervention with improvement observed in the majority of the parameters.