Fliss Matthew D, Stevenson Jordan, Mardan-Dezfouli Sobhan, Li Donna C W, Mitchell Cameron J
School of Kinesiology, The University of British Columbia, Vancouver, British Columbia, Canada.
Appl Physiol Nutr Metab. 2022 Dec 1;47(12):1143-1159. doi: 10.1139/apnm-2022-0263. Epub 2022 Aug 26.
The effect of resistance training with higher- and lower-loads on muscle mass and strength has been extensively studied, while changes in muscle endurance have received less attention. This trial aimed to assess the effect of training load on absolute muscle endurance (AME) and relative muscle endurance (RME). Sixteen untrained women (22.7 ± 3.3 yr: mean ± SD) had one arm and leg randomly assigned to train with higher loads (HL; 80-90% 1RM), and the contralateral limbs trained with lower loads (LL; 30-50% 1RM) thrice weekly to volitional fatigue for 10 weeks. Heavy and light load AME and RME, strength, and muscle mass were assessed pre- and post-training. Strength increased more in the HL compared to LL leg ( < 0.01), but similar increases in strength were observed between upper body conditions ( = 0.46). Lower body heavy and light load AME improved in both conditions, but HL training induced a larger improvement in heavy load AME (HL: 9.3 ± 4.3 vs. LL: 7.5 ± 7.1 repetitions, time × limb < 0.01) and LL training induced a larger improvement in light load AME (LL: 24.7 ± 22.2 vs. HL: 15.2 ± 16.7 repetitions, time × limb = 0.04). In the upper body, HL and LL training induced similar increases in both heavy (time × limb = 0.99), and light load (time × limb = 0.16) AME. Dual-energy X-ray absorptiometry showed no change in leg fat-and-bone-free mass (FBFM) for either condition, and an increase in only LL arm FBFM. AME improved in a manner specific to the training loads used. ClinicalTrials.gov (NCT04547972).
高负荷和低负荷抗阻训练对肌肉质量和力量的影响已得到广泛研究，而肌肉耐力的变化则较少受到关注。本试验旨在评估训练负荷对绝对肌肉耐力（AME）和相对肌肉耐力（RME）的影响。16名未经训练的女性（22.7±3.3岁：均值±标准差），其一侧手臂和腿部被随机分配接受高负荷（HL；80 - 90% 1RM）训练，对侧肢体接受低负荷（LL；30 - 50% 1RM）训练，每周三次，直至出现意志性疲劳，持续10周。在训练前后评估重负荷和轻负荷AME、RME、力量和肌肉质量。与LL组腿部相比，HL组腿部力量增加更多（<0.01），但上半身情况之间力量增加相似（=0.46）。两种情况下，下半身重负荷和轻负荷AME均有所改善，但HL训练使重负荷AME改善更大（HL：9.3±4.3次重复vs. LL：7.5±7.1次重复，时间×肢体<0.01），LL训练使轻负荷AME改善更大（LL：24.7±22.2次重复vs. HL：15.2±16.7次重复，时间×肢体=0.04）。在上半身，HL和LL训练使重负荷（时间×肢体=0.99）和轻负荷（时间×肢体=0.16）AME增加相似。双能X线吸收法显示，两种情况下腿部无脂肪和骨骼的质量（FBFM）均无变化，仅LL组手臂FBFM增加。AME的改善方式与所使用的训练负荷有关。ClinicalTrials.gov（NCT04547972）。
