Antioxidant effects on Muscle Recovery after Moderate Exercise
The way exercise works is by creating enough stress on the muscle to make tiny little tears which heal and over time make the muscle stronger and more energy efficient. Inside the muscle this could either grow the muscle (through hypertrophy training) or cause it to create more mitochondria to increase oxidative capacity and therefore making it more energy efficient (through endurance training) (Merry & Ristow, 2016). Reactive oxygen species (ROS) come into the muscle from both the mitochondria and non-mitochondrial sources, though there are also reactive nitrogen species (RNS) such as nitric oxide which both cause stress. Usually this is combated by the antioxidant defence system made of: superoxide dismutase (SOD), catalase, glutathione peroxidases, peroxiredoxins and thioredoxins. These reduce ROS; though glutathione, for example, can scavenge both ROS and RNS (Merry & Ristow, 2016). Willis (2019) reports that ROS encourages the formation of actin fibres around the tears in the muscle which go on to support the structure when cells repair the holes. This is a normal and regular process. The health industry extensively stouts the positive benefits of antioxidants for wellbeing, and while some conditions do benefit immensely from antioxidant therapy - in a regular healthy person, they may not be as good as they are made to sound. Merry and Ristow (2016) suggest the traditional view of increased oxidative metabolism (that impairs muscle function and causes oxidative damage resulting in ROS) is not a negative response. They in turn, suggest that the excessive dosing of antioxidants promoted in the health and fitness industry hampers normal skeletal muscle adaptation. Beneficial biological adaptations are a response to stressors, such as a low continuous or high intermittent exposure (such as exercise) which would be harmful in larger amounts. Therefore such exercises as HIIT and weight training (done responsibly) would provide enough stress to provoke a positive adaptation, in which the ROS and RNS act as messengers to the body in order to regulate the processes of repair and adaptation. More of the smoke rather than the fire in this example. Willis (2019) describes them as the major “go” signals for muscle growth and recovery, without which important messages may not get delivered. Merry and Ristow (2016) report antioxidant treatment following a single bout of exercise can alter glucose uptake, sodium-potassium pump function, mitochondrial biogenesis markers and insulin sensitivity. They report no solid in vivo evidence to support this, but the theory is consistent with scientific understanding. Ranchordas, Rogerson, Soltani & Costello (2018) suggest rather than spending money on antioxidant supplements that theoretically slow muscle recovery, focus on supporting the balance of ROS and antioxidants with diet and recovery movements which let the body do its job in controlling the balance. This follows the naturopathic principle “Vis medicatrix naturae” whereby the body has an inherent ability to heal itself and simply needs support.
Merry, T. & Ristow, M. (2016). Do antioxidant supplements interfere with skeletal muscle adaptation to exercise training. The Journal of Physiology, vol 594. Issue 18. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5023714/#:~:text=Antioxidants%20can%20prevent%20protein%20oxidation,recovery%20during%20longer%20rest%20periods.
Ranchordas, M., Rogerson, D., Soltani, H. & Costello, J. (2018). Do antioxidant supplements prevent or reduce muscle soreness after exercise. British Journal of Sports Medicine. Retrieved from: https://blogs.bmj.com/bjsm/2018/03/09/do-antioxidant-supplements-prevent-or-reduce-muscle-soreness-after-exercise/
Willis, B. (2019). Why you shouldn’t be always taking antioxidants, especially if you want to build muscle. Examine.com. Retrieved from: https://examine.com/nutrition/antioxidants-muscle-building/