Physically-induced stress from the enduring efforts you put forth in the gym is an unavoidable by-product which can, at a certain level, severely impact the ability to recover. The production of free radicals and reactive oxygen species are an inherent consequence of our body’s natural metabolic processes but can be greatly accelerated by physical activity. Reactive oxygen species (ROS) is an umbrella term for a number of molecules derived from oxygen that, to be blunt, can be quite the nuisance if our body cannot cope with them. There’s actually data to support that an increase in ROS is necessary for muscle adaptation to occur (Jackson, 1999). As such, it must be recognized that these ROS serve an integral purpose for muscle growth. When, however, this increase in free radicals exceeds the body’s ability to neutralize them, a number of deleterious events can happen. Thus coins the term oxidative stress – the disturbance of the pro-oxidant-antioxidant balance in favor of the former (Sies, 1985). This post will dive deeper into the impact oxidative stress has on muscular development and strategies to lessen its detrimental effects on performance.
A Vicious Cycle
The actual sources of ROS is uncertain, but it is now well-known that muscular contractions and the subsequent inflammation due to muscle damage produce them. Low levels of of ROS and reactive nitrogen species are actually required for the normal force production of skeletal muscle (Powers, 2008). But if this increase in is too great for our body to cope with, cellular damage occurs – a negative chain reaction of events called lipid peroxidation ensures, where polyunsaturated fatty acids (mostly) are degraded, creating even more ROS and thus, more damage. Muscle contractile force can falter as a result, leading to weakness, fatigue, and muscle protein “leakage” (Powers, 2008 & Ochoa, 2011). It’s akin to a domino effect – the ROS readily creates a fatty acid radical. This fatty acid radical is unstable and combines with another molecule to create yet another (different) fatty acid radical. This cycle continues as such until terminated. But what if your type of training only serves to aggravate this viscous cycle further? Is the tireless effort you put forth in the gym even yielding any considerable results? What if your diet isn’t providing the necessary nutrients to combat the negative effects of oxidative stress? It’s crucial to understand what’s truly happening to your body when you train – more, for the sheer sake of doing more rarely leads to better results. Understand why or why not you’re progressing towards your goal and understand that diet must be conducive to the type of training you are doing.
Lowering training intensity is not an option (not for my readers, at least), but calculated rest periods, appropriate training periodization, and grasping (and emphasizing) the dietary content of nutritional antioxidants are. Antioxidants are substances we generally associate as being good and healthiful. This is because they are molecules that essentially end the deleterious chain reaction described above. The ensuing section will focus on the latter, describing the powerful role dietary antioxidant can play in the pro-oxidant-antioxidant balance.
Vitamins C & E
The vitamins C and E have numerous physiologic effects – their contribution to cellular protection against free radical damage is especially notable. Vitamin C is hydrophilic (“water-loving”), so it works much better in aqueous environments (the inside of a cell, for example). Vitamin C is unique in that it directly targets certain free radicals, neutralizing them. An interesting study by Jakeman et al. found that muscular strength and contractile force recovered significantly faster after resistance exercise on a dose as low as 400 mg of vitamin C prior to training. This is thought to have been because of vitamin C’s antioxidant properties protecting the endoplasmic reticulum (the component of the cell responsible for protein synthesis) from free radical damage caused by the exercise.
Vitamin C has another interesting property which has led to the recommendation of supplementing it alongside vitamin E. Vitamin C has the ability to regenerate vitamin E (Urso, 2003). Thus, they should be taken together as it is reasonably believed this combination would be more effective than as standalones. Vitamin E, unlike C, is hydrophobic (“water-fearing”), working mostly within cellular membranes (a non-aqueous environment). It has demonstrated protective effects against muscle breakdown and protein leakage in response to exercise at 800 and 1200 IUs respectively (Cannon, 1991 & Itoh, 2000). While there currently is no exact dosing recommendations outlined, most of the research utilized doses of 400-1200 mg. 1,000 mg of vitamin C prior to training (and maybe even post) and 800-1000 IUs of vitamin E taken with a meal containing dietary fat (it’s fat-soluble) are safe and beneficial doses.
It is important to note that the goal of the training session is to introduce stress (including oxidative stress) to which the body must then adapt to. This stress potentiates the body’s ability to change. As such, it is not recommended to take anything that reduces the effect stress has on the body during the training session. Taking antioxidants during the workout would essentially mitigate the session’s primary objective, and thus, not advised.
Melatonin
Melatonin is most commonly associated as a sleep remedy, but it also has uniquely powerful antioxidant properties. Melatonin differs from other antioxidants in that it doesn’t get “recycled” – that is, it doesn’t undergo a repeated cycle of reduction and oxidation. This “redox cycling” may allow for an antioxidants to actually act as pro-oxidants, lessening its effectiveness. Moreover, because of melatonin’s physical and chemical properties, it has the ability to cross virtually all the membranes and barriers of tissues and cells (Reiter, 2009). This leads to easy and wide distribution of its antioxidant benefits.
Ochoa et al. studied the effects of oral melatonin supplementation prior to high intensity exercise and discovered a significant decrease in oxidative stress (using lipid peroxidation as an assessment) and an increase in antioxidant activity. These substantial findings would indicate that consistent oral melatonin supplementation prior to high intensity training (in which free radical damage is most likely) would lead to the maintenance of cellular integrity and protect against the undesirable effects of over-expression of pro-inflammatory mediators.
So, in this regard, melatonin would prove to be an almost essential supplement to have on hand, but we mustn’t cherry pick. The dosing of melatonin is a considerable factor that may not be conducive to everyone’s goal. For this study, melatonin dosing was spread over 3 days: 3 mg taken 2 days before the physical test, 9 mg a day before, 3 mg the morning of, and 3 mg 1 hour before. Is this a realistic supplement protocol to add to your regimen? Probably not. Melatonin, as is widely known, is associated with sleep – it has 3 physiological effects that would not be beneficial prior to training: 1) promotion of sleep onset; 2) maintenance of sleep; and 3) phase-shifting of circadia rhythms (Costello, 2014). Doses as low as 0.1-0.3mg have been shown to affect sleep onset and maintenance qualities while slight higher doses 0.5mg have shown to affect the phase-shifting actions of endogenous melatonin (Costello, 2014).
So, we’re faced with a dilemma – melatonin has powerful antioxidant properties that could significantly reduce oxidative damage at doses that are substantially higher when compared with it’s ability to induce sleep. When situations arise as this, there is no specific recommendation that can be given – it is solely dependent on the individual’s response to the supplement in question. Assess your tolerance of melatonin by starting very low (under a gram) and gradually increasing it every few days. This will allow you to determine your dose for inducing sleep. If the dose is too low for any oxidative stress reducing abilities (around 3 grams), then it probably isn’t a viable supplement choice for you.
Closing Remarks
The question now is, do your workouts induce great enough oxidative stress to be deemed harmful towards your recovery? For competitive athletes, probably so. For those who control the variables in their workouts that determine the degree of muscle activation (rest in-between sets, eccentric contractions, minimal mechanical advantage, etc.) and taking a progressive overload approach, probably so as well. Utilizing the supplemental antioxidants mentioned may help to mitigate some of this potential harm, but thoughtful time spent away from the gym will reign supreme in terms of reducing this stress. Oxidative stress is an inherent result that comes with resistance training – it’s a necessary component of the adaptation process after all. While the body can certainly cope with some amount, unregulated amounts seriously impact one’s ability to progress. Hopefully this post serves to bring awareness to what over-training really means – it is the state in which the training program yields progressively diminishing returns to the point of total detriment. Avoid this vicious cycle through awareness and logical action and your progress will have one less barrier to contend with.
References:
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Thoughts?