Prolonged Low‐ to Moderate‐Intensity Exercise Improves Metabolic and Oxidative Profiles in Healthy Adults
Authors: Gagnon Dominique D. , Dorman Sandra C. , Ritchie Stephen , Mutt Shivaprakash Jagalur , Stenbäck Ville , Walkowiak Jerek , Herzig Karl‐Heinz 
Published: June 2021

BackgroundOxidative stress results in cellular lipid, protein and DNA oxidation as well as overall metabolic dysfunction. This may result in chromosomal damage, telomere erosion, and accelerated cellular aging. Long‐term participation in physical activity promotes healthy metabolic and oxidative profiles whereas the effects of prolonged and continuous exercise, are unknown. Therefore, this study investigated the effects of prolonged exercise on oxidative and metabolic stress as well as cellular ageing in healthy adults participating in multi‐day wilderness expedition.MethodsTwenty‐seven people participated in the study. Sixteen went on a 14‐day, 260‐km wilderness canoeing expedition (12 males) (E) (24 ± 7 yrs, 72 ± 6 kg, 178 ± 8.0 cm, 18.4 ± 8.4 %BF, 47.5 ± 9.3 mlO2·kg−1·min−1), requiring 6–9 hrs of low to moderate exercise daily. Eleven acted as controls (7 males) (C) (31 ± 11 yrs, 72 ± 15 kg, 174 ± 10 cm, 22.8 ± 10.0 %BF, 47.1 ± 9.0 mlO2·kg−1·min−1). Blood sample collection was completed before and after the expedition. ANCOVA analyses, with age, gender, fitness, and baseline values as covariates, were performed on serum metabolic, hormonal and oxidative variables while telomere length was isolated from blood mononuclear cells.ResultsSerum total cholesterol, high‐ and low‐density lipoprotein, testosterone, insulin, sodium, potassium, urea and chloride concentrations were not different between groups. Serum triglycerides (TG), glucose (GLU), and creatinine (CR) levels were all lower following the expedition (TG, E: 69 ± 18 vs. C: 106 ± 45 mg·dL−1; p = 0.002: GLU, E: 86.2 ± 5.4 vs. C: 95.8 ± 8.8 mg·dL−1; p < 0.001: CR E: 0.89 ± 0.13 vs. C: 0.96 ± 0.16 mg·dL−1; p < 0.001). Oxidative stress, as assessed via malondialdehyde (MDA) was unaffected (E: 4.2 ± 1.3 vs. C: 4.1 ± 0.7 μM; p > 0.05) but superoxidase dismutase activity (SOD), representative of antioxidant activity, was greater in the expedition group (E: 3.1 ± 0.4 vs. C: 0.8 ± 0.5 U·ml−1; p < 0.001). Telomere length, as a cellular sign for stress and senescence, was unchanged (E: 1.00 ± 0.48 vs. C: 0.89 ± 0.28 TS ratio; p = 0.77).ConclusionThese results indicate a modest improvement in metabolic and oxidative profiles following 14 days of low to moderate exercise in healthy young individuals. The observed changes in SOD suggest a stronger cellular protective response from antioxidants to counteract the exercise‐associated production of pro‐oxidant free radicals and reactive oxygen species during prolonged low‐moderate physical loading. Although improved antioxidant activity may lead to increased telomere length, it seems that the present exercise stimulus was insufficient to promote a positive cellular aging profile with concordant chromosomal changes in our young participants.Support or Funding InformationThe work was supported by a Laurentian University Research Fund grant and a travel grant from the University of OuluThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.