אימונים Low-Volume Interval Training Improves Muscle Oxidative Capacity in Sedentary Adults.

[Mike Bikov]

Med Sci Sports Exerc. 2011 Mar 25. [Epub ahead of print]
Low-Volume Interval Training Improves Muscle Oxidative Capacity in Sedentary Adults.

Hood MS, Little JP, Tarnopolsky MA, Myslik F, Gibala MJ.

1Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario L8S 4K1; and 2Department of Pediatrics and Medicine, McMaster University, Hamilton, Ontario, L8N 3Z5 CANADA.
Abstract

INTRODUCTION: High intensity interval training (HIT) increases skeletal muscle oxidative capacity similar to traditional endurance training, despite a low total exercise volume. Much of this work has focused on young active individuals and it is unclear if the results are applicable to older, less active populations. In addition, many studies have employed "all out", variable-load exercise interventions (e.g., repeated Wingate Tests) that may not be practical for all individuals. We therefore examined the effect of a more practical low-volume, sub-maximal, constant-load HIT protocol on skeletal muscle oxidative capacity and insulin sensitivity in middle-aged adults who may be at higher risk for inactivity-related disorders.

METHODS: Seven sedentary but otherwise healthy individuals (3 women) with a mean (±SD) age, body mass index and peak oxygen uptake (VO2peak) of 45±5 y, 27±5 kg/m and 30±3 ml·kg·min-1 performed 6 training sessions over 2 wk. Each session involved 10 x 1 min cycling at ~60% of peak power achieved during a ramp VO2peak test (eliciting ~80-95% of heart rate reserve) with 1 min recovery between intervals. Needle biopsy samples (v. lateralis) were obtained before training and ~72 h after the final training session.

RESULTS: Muscle oxidative capacity, as reflected by the protein content of citrate synthase and cytochrome oxidase subunit IV, increased by ~35% after training. The transcriptional co-activator PGC-1α was increased by ~56% following training, but the transcriptional co-repressor RIP140 remained unchanged. GLUT4 protein content increased ~260% and insulin sensitivity, based on the ISI (HOMA), improved by ~35% after training.

CONCLUSION: Constant-load, low-volume HIT may be a practical, time-efficient strategy to induce metabolic adaptations that reduce the risk for inactivity-related disorders in previously sedentary middle-aged adults.

PMID: 21448086 [PubMed - as supplied by publisher]​

😃😃