Effects of downhill walking training on aerobic and neuromuscular fitness of young adults

Abstract Eccentric exercise training using low intensity-high volume approach has been performed to improve maximal muscle strength and power. The aim of this study was to compare the effects of short-term downhill walking and level walking training on lower limb strength and maximal oxygen uptake of active individuals. Eighteen young adults were divided into level walking group (n = 9) or downhill walking training group (n = 9). Both groups performed a four-week training program. The level walking group performed seven level walking sessions per week, while the downhill walking group walked downhill (-16%) in the same weekly frequency. One week before and one week after the training protocol, maximal oxygen uptake, muscle-bone cross-sectional area and isometric peak torque of knee extensors and plantar flexors were assessed for both groups. A significant group vs. time interaction was found only for cross sectional area of plantar flexors (PF), showing increases for the downhill walking group (112.6 ± 28.9 cm2 vs. 115.9 ± 29 cm2) but not for the level walking group (94.9 ± 23.3 cm2vs. 94.6 ± 228 cm2). Maximal oxygen uptake remained unaltered after training for both groups and IPT was increased after training for both groups. It was concluded that short-term downhill walking training does not seem to be efficient in promoting improvements in cardiorrespiratory fitness of young adults. However, it seems to promote gains in some variables related to neuromuscular fitness.

摘要：采用低强度高容量方案的离心运动训练（eccentric exercise training），已被应用于提升肌肉最大力量与爆发力。本研究旨在对比短期下坡行走与平地行走训练，对年轻常锻炼者下肢力量及最大摄氧量（maximal oxygen uptake）的影响。18名年轻受试者被分为平地行走组（n = 9）与下坡行走训练组（n = 9），两组均完成为期4周的训练计划。平地行走组每周开展7次平地行走训练，而下坡行走组以相同周频次进行坡度为-16%的下坡行走。在训练方案实施前后各一周，对两组受试者的最大摄氧量、肌骨横截面积，以及膝伸肌（knee extensors）与跖屈肌（plantar flexors）的等长峰值扭矩（isometric peak torque）进行评估。仅在跖屈肌（PF）横截面积上观察到显著的组间×时间交互效应：下坡行走组的横截面积出现显著提升（112.6 ± 28.9 cm² vs. 115.9 ± 29.0 cm²），而平地行走组无明显变化（94.9 ± 23.3 cm² vs. 94.6 ± 228 cm²）。两组受试者的最大摄氧量在训练后均无显著改变，且两组的等长峰值扭矩均有所提升。研究结论表明，短期下坡行走训练似乎无法有效提升年轻成年人的心肺耐力（cardiorrespiratory fitness），但可改善部分与神经肌肉功能（neuromuscular fitness）相关的指标。