Effect of Concurrent Sprint Interval and Resistance Training on Measures of Strength, Power, and Aerobic Performance

Abstract

PURPOSE: The purpose of this investigation was to determine if sprint interval training (SIT) performed concurrently with resistance training resulted in adaptive interference, had no effect, or caused synergistic enhancement to measures of strength, power, and VO2max in recreationally active females when compared to resistance training alone. METHODS: 28 healthy females (20.3 ±1.7 yrs, 35.4 ± 4.0 ml.kg-1.min-1 VO2max, 113 ± 17 lbs. 1 repetition max (1 RM) back squat) were asked to complete a 12 week resistance training study. Preliminary and post testing consisted of 1 RM back squat, maximal isometric squat, rate of force development (RFD), cycle ergometer based anaerobic power evaluations, lactate threshold (LT), and VO2max. Following initial testing, participants were matched according to 1RM back squat and VO2max values and randomly assigned to one of two groups: concurrent training (CT) that completed both resistance and SIT protocols, and resistance training (RT) which only completed the resistance training protocol. Training was completed 3 days per week and lasted for 11 total weeks. All resistance training was completed in the morning with each participant completing the protocol at the same time each day. Separated by at least 4 hours, CT participants returned and completed SIT. RESULTS: 1 RM squat and maximal isometric force values were significantly elevated following training in both RT and CT (both P < 0.01). RFD was not significantly altered in either group. Similarly, modified Wingate testing revealed significant increases to peak and mean anaerobic power values in both ST (P < 0.05) and CT (P < 0.01) with no statistical difference between group response differences. VO2max also increased as a result of resistance and concurrent training (P < 0.01). Predicted zero incline velocity that would elicit VO2max (Vmax) values were significantly elevated in both groups (P < 0.01) although concurrent training resulted in a significantly greater adaptive response (P < 0.01). LT values were not affected by training, although the velocity associated with LT (VLT) increased significantly in both groups following training (P < 0.01). CONCLUSON: These data indicate that resistance training in isolation and sprint interval based concurrent training result in identical improvements to measures of strength, power, and VO2max with no indication of adaptive interference. Only Vmax adaptations supported the hypothesis of synergistic enhancement. These findings may be the result of commonalities between the adaptive responses to sprint interval and resistance training.