Effect of speed endurance and strength training on performance, running economy and muscular adaptations in endurance-trained runners.

Abstract

To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. Sixteen male endurance runners (VO2-max: ~60mlkg(-1)min(-1)) were randomly assigned to either a combined strength and SE training (CSS; n=9) or a control (CON; n=7) group. For 8weeks, CSS replaced their normal moderate-intensity training (~63kmweek(-1)) with SE (2×week(-1)) and strength training (2×week(-1)) as well as aerobic high (1×week(-1)) and moderate (1×week(-1)) intensity training with a reduction in total volume of~58%, whereas CON continued their training (~45kmweek(-1)). In CSS, 400-m and Yo-Yo intermittent recovery test performance was improved by 5% (P<0.01) and 19% (P<0.001), respectively, during the intervention period. Maximal aerobic speed was 0.6kmh(-1) higher (P<0.05), and maximal activity of lactate dehydrogenase subunits 1 and 2 was 17% (P<0.05) higher after compared to before the intervention period. Time to exhaustion and peak blood lactate during an incremental treadmill test was 9% (P<0.05) and 32% (P<0.01), respectively, higher and expression of Na(+)-K(+) pump β1 subunit was 15% higher (P<0.05) after compared to before the intervention period. 10-K performance, maximum oxygen uptake and running economy were unchanged. In CON, no changes were observed. Adding strength and speed endurance training, along with a reduced training volume, can improve short-term exercise capacity and induce muscular adaptations related to anaerobic capacity in endurance-trained runners.