Gagnon Dominique D, Dorman Sandra, Ritchie Stephen, Mutt Shivaprakash Jagalur, Stenbäck Ville, Walkowiak Jarosław, Herzig Karl-Heinz
Laboratory of Environmental Exercise Physiology, School of Human Kinetics, Laurentian University, Sudbury, ON, Canada.
Center of Research in Occupational Safety and Health, Laurentian University, Sudbury, ON, Canada.
Front Physiol. 2019 Sep 3;10:1123. doi: 10.3389/fphys.2019.01123. eCollection 2019.
Oxidative stress results in lipid, protein, and DNA oxidation, resulting in telomere erosion, chromosomal damage, and accelerated cellular aging. Training promotes healthy metabolic and oxidative profiles whereas the effects of multi-day, prolonged, and continuous exercise are unknown. This study investigated the effects of multi-day prolonged exercise on metabolic and oxidative stress as well as telomere integrity in healthy adults.
Fifteen participants performed a 14-day, 260-km, wilderness canoeing expedition (12 males) (EXP) (24 ± 7 years, 72 ± 6 kg, 178 ± 8.0 cm, 18.4 ± 8.4% BF, 47.5 ± 9.3 mlO kg min), requiring 6-9 h of low- to moderate-intensity exercise daily. Ten controls participated locally (seven males) (CON) (31 ± 11 years, 72 ± 15 kg, 174 ± 10 cm, 22.8 ± 10.0% BF, 47.1 ± 9.0 mlO kg min). Blood plasma, serum, and mononuclear cells were sampled before and after the expedition to assess hormonal, metabolic, and oxidative changes.
Serum cholesterol, high- and low-density lipoprotein, testosterone, insulin, sodium, potassium, urea, and chloride concentrations were not different between groups, whereas triglycerides, glucose, and creatinine levels were lower following the expedition ( < 0.001). Malondialdehyde and relative telomere length (TL) were unaffected (EXP: 4.2 ± 1.3 vs. CON: 4.1 ± 0.7 μM; > 0.05; EXP: 1.00 ± 0.48 vs. CON: 0.89 ± 0.28 TS ratio; = 0.77, respectively); however, superoxidase dismutase activity was greater in the expedition group (3.1 ± 0.4 vs. 0.8 ± 0.5 U ml; < 0.001).
These results indicate a modest improvement in metabolic and oxidative profiles with increased superoxidase dismutase levels, suggesting an antioxidative response to counteract the exercise-associated production of free radicals and reactive oxygen species during prolonged exercise, mimicking the effects from long-term training. Although improved antioxidant activity may lead to increased TL, the present exercise stimulus was insufficient to promote a positive cellular aging profile with concordant chromosomal changes in our healthy and young participants.
氧化应激会导致脂质、蛋白质和DNA氧化，进而造成端粒侵蚀、染色体损伤以及细胞衰老加速。运动可促进健康的代谢和氧化状态，然而多日、长时间且持续运动的影响尚不清楚。本研究调查了多日长时间运动对健康成年人代谢、氧化应激以及端粒完整性的影响。
15名参与者（12名男性）进行了为期14天、260公里的野外皮划艇探险（EXP组）（年龄24±7岁，体重72±6千克，身高178±8.0厘米，体脂率18.4±8.4%，摄氧量47.5±9.3毫升/千克·分钟），每天需要进行6至9小时的低至中等强度运动。10名对照者在当地参与（7名男性）（CON组）（年龄31±11岁，体重72±15千克，身高174±10厘米，体脂率22.8±10.0%，摄氧量47.1±9.0毫升/千克·分钟）。在探险前后采集血浆、血清和单核细胞样本，以评估激素、代谢和氧化变化。
两组之间血清胆固醇、高密度和低密度脂蛋白、睾酮、胰岛素、钠、钾、尿素和氯的浓度没有差异，而探险后甘油三酯、葡萄糖和肌酐水平较低（<0.001）。丙二醛和相对端粒长度（TL）未受影响（EXP组：4.2±1.3对比CON组：4.1±0.7微摩尔；>0.05；EXP组：1.00±0.48对比CON组：0.89±0.28 TS比值；分别为=0.77）；然而，探险组的超氧化物歧化酶活性更高（3.1±0.4对比0.8±0.5单位/毫升；<0.001）。
这些结果表明随着超氧化物歧化酶水平升高，代谢和氧化状态有适度改善，这表明在长时间运动期间存在一种抗氧化反应来抵消与运动相关的自由基和活性氧的产生，类似于长期训练的效果。尽管抗氧化活性的提高可能会导致端粒长度增加，但目前的运动刺激不足以在我们健康且年轻的参与者中促进积极的细胞衰老状态以及相应的染色体变化。
