Metabolic Response to Four Weeks of Muscular Endurance Resistance Training

Abstract

Background: Previous investigations have shown that muscular endurance resistance training (MERT) is conducive in improving the onset of blood lactate accumulation (OBLA). However, the metabolic response and time course for adaption is still unclear. Objective: The aims of the current study were to evaluate and track the metabolic response to an individual session of MERT as well as to assess performance adaptations of supplementing an aerobic exercise training program with four weeks of MERT. Methods: Seventeen aerobically active men were randomly assigned to either the experimental (EX) or control group (CON), 9 EX and 8 CON. Baseline measures included a graded exercise test (GXT) and 1-repetition maximum (1RM) testing for leg press (LP), leg curl (LC), and leg extension (LE). CON continued their regular aerobic activity while the EX supplemented their regular aerobic exercise with 4 weeks of MERT. Results: No significant group differences were observed for all pre-training variables. Following four weeks of training no significant differences in cardiorespiratory or metabolic variables were observed for either group. However, significant improvements in LC and LE 1-RM were observed in EX compared to CON. Substantial accumulations in blood lactate were observed following each MERT session. Conclusion: Four weeks of MERT did not improve cardiorespiratory or metabolic variables, but did significantly improve LC and LE. MERT was also observed to induce a blood lactate response similar to that of HIIT. These findings suggest greater than four weeks is need to see metabolic adaptations conducive for improved aerobic performance using MERT.