Redox biology of exercise: an integrative and comparative consideration of some overlooked issues

Abstract

SummaryThe central aim of this review is to address the highly multidisciplinary topic of redox biology as related to exercise using an integrative and comparative approach rather than focusing on blood, skeletal muscle or humans. An attempt is also made to redefine ʻoxidative stressʼ as well as to introduce the term ʻalterations in redox homeostasisʼ to describe changes in redox homeostasis indicating oxidative stress, reductive stress or both. The literature analysis shows that the effects of non-muscledamaging exercise and muscle-damaging exercise on redox homeostasis are completely different. Non-muscle-damaging exercise induces alterations in redox homeostasis that last a few hours post exercise, whereas muscle-damaging exercise causes alterations in redox homeostasis that may persist for and/or appear several days post exercise. Both exhaustive maximal exercise lasting only 30s and isometric exercise lasting 1-3min (the latter activating in addition a small muscle mass) induce systemic oxidative stress. With the necessary modifications, exercise is capable of inducing redox homeostasis alterations in all fluids, cells, tissues and organs studied so far, irrespective of strains and species. More importantly, ʻexercise-induced oxidative stressʼ is not an ʻoddityʼ associated with a particular type of exercise, tissue or species. Rather, oxidative stress constitutes a ubiquitous fundamental biological response to the alteration of redox homeostasis imposed by exercise. The hormesis concept could provide an interpretative framework to reconcile differences that emerge among studies in the field of exercise redox biology. Integrative and comparative approaches can help determine the interactions of key redox responses at multiple levels of biological organization.Key words: antioxidant, biomarker, eccentric, free radical, training. THE JOURNAL OF EXPERIMENTAL BIOLOGY 1616The ʻgoodʼ (antioxidants), the ʻbadʼ (reactive species) and the ʻuglyʼ (oxidative stress) 1 The distinction drawn in the section heading is schematically used to parody the popular manichaeistic view that antioxidants are considered 'useful' entities, reactive species are considered 'harmful' entities and oxidative stress is considered a 'negative' state. Certainly, the reality is much more complicated and antioxidants, reactive species and oxidative stress can serve both useful and detrimental roles, which are dependent on the biological context (within an organism), which in turn are greatly dependent on the environmental context (outside an organism). AntioxidantsAdmittedly, to define the term 'antioxidant' is a difficult task. In this paper, antioxidant is defined as any mechanism, structure and/or substance that delays, prevents or removes oxidative modifications to a target molecule (Halliwell and Gutteridge, 2007;Pamplona and Costantini, 2011). Antioxidants can be complex molecules such as the superoxide dismutases and peroxiredoxins, or simpler ones such as uric acid and glutathione (Gutteridge and Halliwell, 2010). They can be broa...

Physical training status determines oxidative stress and redox changes in response to an acute aerobic exercise

“…Generally, in all redox systems, the relative amounts of reduced (more negative) and oxidized (more positive) form determine cellular redox state [2] and more reduced redox represents healthy status [5], while more oxidized form predisposes individuals to aging and diseases [6,7]. Therefore, the ratio of GSH and GSSG is in the core of the redox hypothesis [8,9] and directly reflects intracellular redox alterations at resting and provocative states [10].…”

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“…[9] Promising in this respect is considered quinazoline derivatives with antihypoxic, neuroand cardioprotective effects, which also play an important role in the high effectiveness of physical work. [1,[3][4][5] Sodium 2-(tetrazol[1,5-c]quinazolin-5-ylthio) acetate (compound KB-28) appeared to be a leader in the previous studies of actoprotective activity of new derivatives of 5-R-thio-tetrazol [1,5-c]quinazoline in normal and complicated experimental conditions. [8,10] The above-mentioned substances were synthesized at the Department of Organic Chemistry of Zaporizhia State Medical University under control of prof. S. I. Kovalenko.…”

“…This process is protective in nature, since it prevents a body from full exhaustion through economization of all processes and preservation of physiological reserves. [1][2][3][4] The rate of fatigue is significantly influenced by metabolic changes that occur in physically loaded body. We know that to maintain contractile function of muscles, they should be continuously provided with energy in the form of ATP.…”

The Association between Physical Exercise and Reactive Oxygen Species (ROS) Production

“…The molecular mechanism involved in oxidative stress and muscle damage induced by an acute exercise protocol has been the subject of intense investigation in recent years [32][33][34]. Oxygen consumption in the human body is increased many times when an individual is exercising at high intensities [36][37][38]. The oxygen utilization by skeletal muscles during intense physical exertion may increase approximately 15 to 20-fold compared with consumption at rest [35][36][37].…”