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

Purpose The aim of this study was to compare the combined effects of resistance and sprint training, with very short efforts (5 s), on aerobic and anaerobic performances, and cardiometabolic health-related parameters in young healthy adults. Methods Thirty 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 5 s separated by 24 s of recovery, totalizing ~ 13 min per session, with 48–72 h 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 (HR mean ) were monitored during sessions. Incidental physical activity (PA), dietary intake and perceived stress were also controlled. Results Maximum oxygen consumption ( V O 2max ) significantly increased in SITG and CTG ( P