Multi-Day Prolonged Low- to Moderate-Intensity Endurance Exercise Mimics Training Improvements in Metabolic and Oxidative Profiles Without Concurrent Chromosomal Changes in Healthy Adults

Dominique D Gagnon; Sandra Dorman; Stephen Ritchie; Shivaprakash Jagalur Mutt; Ville Stenbäck; Jarosław Walkowiak; Karl-Heinz Herzig

doi:10.3389/fphys.2019.01123

Multi-Day Prolonged Low- to Moderate-Intensity Endurance Exercise Mimics Training Improvements in Metabolic and Oxidative Profiles Without Concurrent Chromosomal Changes in Healthy Adults

Front Physiol. 2019 Sep 3:10:1123. doi: 10.3389/fphys.2019.01123. eCollection 2019.

Authors

Dominique D Gagnon^{1

2}, Sandra Dorman^{1

2

3}, Stephen Ritchie^{1

2}, Shivaprakash Jagalur Mutt^{4

5}, Ville Stenbäck^{4

5}, Jarosław Walkowiak⁶, Karl-Heinz Herzig^{4

5

6}

Affiliations

¹ Laboratory of Environmental Exercise Physiology, School of Human Kinetics, Laurentian University, Sudbury, ON, Canada.
² Center of Research in Occupational Safety and Health, Laurentian University, Sudbury, ON, Canada.
³ Northern Ontario School of Medicine, Sudbury, ON, Canada.
⁴ Research Unit of Biomedicine, Department of Physiology and Biocenter of Oulu, University of Oulu, Oulu, Finland.
⁵ Medical Research Center, Oulu University Hospital and University of Oulu, Oulu, Finland.
⁶ Department of Gastroenterology and Metabolism, Poznan University of Medical Sciences, Poznań, Poland.

Abstract

Background: 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.

Methods: 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 mlO₂ kg^-1 min^-1), 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 mlO₂ kg^-1 min^-1). Blood plasma, serum, and mononuclear cells were sampled before and after the expedition to assess hormonal, metabolic, and oxidative changes.

Results: 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 (p < 0.001). Malondialdehyde and relative telomere length (TL) were unaffected (EXP: 4.2 ± 1.3 vs. CON: 4.1 ± 0.7 μM; p > 0.05; EXP: 1.00 ± 0.48 vs. CON: 0.89 ± 0.28 TS ratio; p = 0.77, respectively); however, superoxidase dismutase activity was greater in the expedition group (3.1 ± 0.4 vs. 0.8 ± 0.5 U ml^-1; p < 0.001).

Conclusion: 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.

Keywords: hormones; metabolism; oxidative stress; prolonged exercise; telomeres.