Exercise training is considered as a potential intervention to counteract muscle degeneration in cancer cachexia. However, evidence to support such intervention is equivocal. Therefore, we investigated the effect of exercise training, i.e. voluntary wheel running, on muscle wasting, functional capacity, fiber type composition and vascularization during experimental cancer cachexia in mice. Balb/c mice were injected with PBS (CON) or C26 colon carcinoma cells to induce cancer cachexia (C26). Mice had free access to a running wheel in their home cage (CON_EX and C26_EX, n = 8–9) or were sedentary (CON_S and C26_S, n = 8–9). Mice were sacrificed 18 days upon tumor cell injection. Immunohistochemical analyes were performed on m. gastrocnemius and quadriceps, and ex vivo contractile properties were assessed in m. soleus and extensor digitorum longus (EDL). Compared with CON, C26 mice exhibited body weight loss (~ 20 %), muscle atrophy (~ 25 %), reduced grip strength (~ 25 %), and lower twitch and tetanic force (~ 20 %) production in EDL but not in m. soleus. Furthermore, muscle of C26 mice were characterizd by a slow-to-fast fiber type shift (type IIx fibers: +57 %) and increased capillary density (~ 30 %). In C26 mice, wheel running affect neither body weight loss, nor muscle atrophy or functional capacity, nor inhibited tumor growth. However, wheel running induced a type IIb to type IIa fiber shift in m. quadriceps from both CON and C26, but not in m. gastrocnemius. Wheel running does not exacerbate muscular degeneration in cachexic mice, but, when voluntary, is insufficient to improve the muscle phenotype.

运动训练被认为是对抗癌症恶病质中肌肉退化的潜在干预措施。然而，支持这种干预的证据是模棱两可的。因此，我们在实验性癌症恶病质小鼠中研究了运动训练（即自愿轮式跑步）对肌肉萎缩、功能能力、纤维类型组成和血管形成的影响。Balb/c 小鼠被注射 PBS (CON) 或 C26 结肠癌细胞以诱导癌症恶病质 (C26)。小鼠可以自由使用它们家笼中的跑轮（CON _EX和 C26 _EX，n = 8-9）或久坐不动（CON _S和 C26 _S, n = 8-9)。在肿瘤细胞注射后18天处死小鼠。对 m 进行免疫组织化学分析。腓肠肌和股四头肌以及离体收缩特性以 m 为单位进行评估。比目鱼肌和趾长伸肌（EDL）。与 CON 相比，C26 小鼠在 EDL（但在米。比目鱼属。此外，C26 小鼠肌肉的特征是纤维类型从慢到快转变（IIx 型纤维：+57%）和毛细血管密度增加（~30%）。在 C26 小鼠中，轮式跑步既不会影响体重减轻，也不会影响肌肉萎缩或功能能力，也不会抑制肿瘤生长。然而，车轮运行会导致 IIb 型到 IIa 型纤维偏移，单位为 m。来自 CON 和 C26 的股四头肌，但不是以 m 为单位。腓肠肌。轮式跑步不会加剧恶病质小鼠的肌肉退化，但如果是自愿的，则不足以改善肌肉表型。