Unité de Physiologie de l'Exercice et des Activités en Conditions Extrêmes, Département Environnements Opérationnels, Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France.
Ecole du Val-de-Grâce, Paris, France.
Physiol Rep. 2021 Aug;9(16):e14686. doi: 10.14814/phy2.14686.
Aerobic training leads to well-known systemic metabolic and muscular alterations. Heat acclimation may also increase mitochondrial muscle mass. We studied the effects of heat acclimation combined with endurance training on metabolic adaptations of skeletal muscle. Thirty-two rats were divided into four groups: control (C), trained (T), heat-acclimated (H), and trained with heat acclimation (H+T) for 6 weeks. Soleus muscle metabolism was studied, notably by the in situ measurement of mitochondrial respiration with pyruvate (Pyr) or palmitoyl-coenzyme A (PCoA), under phosphorylating conditions ( ) or not ( ). Aerobic performance increased, and retroperitoneal fat mass decreased with training, independently of heat exposure (p < 0.001 and p < 0.001, respectively). Citrate synthase and hydroxyl-acyl-dehydrogenase activity increased with endurance training (p < 0.001 and p < 0.01, respectively), without any effect of heat acclimation. Training induced an increase of the and for PCoA (p < .001 and p < .01, respectively), without interference with heat acclimation. The training-induced increase of (p < 0.01) for pyruvate oxidation was limited when combined with heat acclimation (-23%, p < 0.01). Training and heat acclimation independently increased the for pyruvate (+60% p < 0.001 and +50% p = 0.01, respectively), without an additive effect of the combination. Heat acclimation doubled the training effect on muscle glycogen storage (p < 0.001). Heat acclimation did not improve mitochondrial adaptations induced by endurance training in the soleus muscle, possibly limiting the alteration of carbohydrate oxidation while not facilitating fatty-acid utilization. Furthermore, the increase in glycogen storage observed after HA combined with endurance training, without the improvement of pyruvate oxidation, appears to be a hypoxic metabolic phenotype.
有氧运动训练会导致众所周知的全身代谢和肌肉变化。热适应也可能增加肌肉中线粒体的质量。我们研究了热适应与耐力训练相结合对骨骼肌代谢适应的影响。32 只大鼠被分为四组：对照组（C）、训练组（T）、热适应组（H）和热适应加训练组（H+T），进行了 6 周的训练。通过原位测量有磷（ ）或无磷（ ）条件下丙酮酸（Pyr）或棕榈酰辅酶 A（PCoA）的线粒体呼吸，研究比目鱼肌的代谢，特别是在氧化磷酸化条件下。有氧能力提高，腹膜后脂肪质量减少，与热暴露无关（p<0.001 和 p<0.001）。柠檬酸合酶和羟基酰基辅酶 A 脱氢酶活性随耐力训练而增加（p<0.001 和 p<0.01），不受热适应的影响。训练诱导 PCoA 的 和 增加（p<0.001 和 p<0.01），而不干扰热适应。当与热适应结合时，训练诱导的丙酮酸氧化 增加受到限制（-23%，p<0.01）。训练和热适应独立增加了丙酮酸的 （p<0.01，分别增加 60%和 50%），结合没有叠加效应。热适应使肌肉糖原储存的训练效果增加一倍（p<0.001）。热适应没有改善比目鱼肌耐力训练引起的线粒体适应，可能限制碳水化合物氧化的改变，而不促进脂肪酸的利用。此外，在 HA 结合耐力训练后观察到的糖原储存增加，而丙酮酸氧化没有改善，这似乎是一种缺氧代谢表型。
