Research Centre for Musculoskeletal Science & Sports Medicine, Department of Life Sciences, Manchester Metropolitan University, John Dalton Building; Chester Street, Manchester, M1 5GD, UK.
Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania.
Geroscience. 2021 Apr;43(2):741-757. doi: 10.1007/s11357-020-00224-x. Epub 2020 Jul 8.
It has been observed that there is an inverse relationship between fiber size and oxidative capacity due to oxygen, ADP, and ATP diffusion limitations. We aimed to see if regular endurance exercise alongside a hypertrophic stimulus would lead to compromised adaptations to both, particularly in older animals. Here we investigated the effects of combining overload with regular endurance exercise in young (12 months) and old (26 months) male mice. The plantaris muscles of these mice were overloaded through denervation of synergists to induce hypertrophy and the mice ran on a treadmill for 30 min per day for 6 weeks. The hypertrophic response to overload was not blunted by endurance exercise, and the increase in fatigue resistance with endurance exercise was not reduced by overload. Old mice demonstrated less hypertrophy than young mice, which was associated with impaired angiogenesis and a reduction in specific tension. The data of this study suggest that combining endurance exercise and overload induces the benefits of both types of exercise without compromising adaptations to either. Additionally, the attenuated hypertrophic response to overload in old animals may be due to a diminished capacity for capillary growth.
已经观察到，由于氧气、ADP 和 ATP 的扩散限制，纤维大小与氧化能力之间存在反比关系。我们旨在观察在存在肥大刺激的情况下，定期进行耐力运动是否会导致两者的适应能力受损，尤其是在老年动物中。在这里，我们研究了在年轻（12 个月）和年老（26 个月）雄性小鼠中结合超负荷和常规耐力运动的效果。通过对协同肌进行去神经支配来使这些小鼠的比目鱼肌超负荷，以诱导肥大，并且让小鼠每天在跑步机上跑 30 分钟，持续 6 周。耐力运动并没有使超负荷引起的肥大反应减弱，而耐力运动对疲劳抵抗力的提高也没有因超负荷而降低。与年轻小鼠相比，老年小鼠的肥大程度较低，这与血管生成受损和比目鱼肌特定张力降低有关。本研究的数据表明，将耐力运动和超负荷结合起来可以同时获得两种运动的益处，而不会对任何一种适应能力造成损害。此外，老年动物对超负荷的肥大反应减弱可能是由于毛细血管生长能力下降所致。
