Effects of concurrent endurance and strength training on running economy and VO2 kinetics. Med Sci Sports Exerc

endurance training influences the running economy (CR) and the oxygen uptake (V ˙ O2) kinetics in heavy exercise by accelerating the primary phase and attenuating the V ˙ O2 slow component. However, the effects of heavy weight training (HWT) in combination with endurance training remain unclear. The purpose of this study was to examine the influence of a concurrent HWTendurance training on CR and the V ˙ O2 kinetics in endurance athletes. Methods: Fifteen triathletes were assigned to endurancestrength (ES) or endurance-only (E) training for 14 wk. The training program was similar, except ES performed two HWT sessions a week. Before and after the training period, the subjects performed 1) an incremental field running test for determination of V ˙ O2max and the velocity associated (VV ˙ O2max), the second ventilatory threshold (VT2); 2) a 3000-m run at constant velocity, calculated to require 25 % of the difference between V ˙ O2max and VT2, to determine CR and the characteristics of the V ˙ O2 kinetics; 3) maximal hopping tests to determine maximal mechanical power and lower-limb stiffness; 4) maximal concentric lower-limb strength measurements. Results: After the training period, maximal strength were increased (P 0.01) in ES but remained unchanged in E. Hopping power decreased in E (P 0.05). After training, economy (P 0.05) and hopping power (P 0.001) were greater in ES than in E. V ˙ O2max, leg hopping stiffness and the V ˙ O2 kinetics were not significantly affected by training either in ES or E. Conclusion: Additional HWT led to improved maximal strength and running economy with no significant effects on the V ˙ O2 kinetics pattern in heavy exercise. Key Words: ENERGY COST, MAXIMAL OXYGEN CONSUMPTION, OXYGEN UPTAKE SLOW COMPONENT, HOPPING POWER The combined effects of concurrent strength andendurance training on the endurance performanceof untrained (12,16,18,19,25) or trained athlete