If you ask any sports person what they are most worried about, they will generally respond with one of two possible answers: injury or illness. The consensus of most scientists is that exercise is good for you, but up to a point.
Unfortunately, daily or twice daily heavy exercise training over months or years can become burdensome to your body, meaning enhanced chances of realising these injury and illness fears.
Elite athletes are prepared to try extreme measures to speed up recovery from one session to the next. I remember sitting in a freezing aqueduct on a daily basis in the Victorian Alps when on an altitude training camp with Australian runners. Sports people will also try all sorts of pills and potions if it means adding an extra session to their weekly schedule. It is not as simple as ‘one size fits all’ though – appropriate supplement choices, if any, will depend on the underlying physiology of the athlete. The Functional Nutrition approach to recovery will be discussed here, along with the surrounding controversies – should we or shouldn’t we supplement to aid recovery from training?
FUNCTIONAL MEDICINE WEB
Every physiological system in our body influences the health of every other physiological system and often certain bodily functions can be weakened by seemingly unrelated issues. Immunity and musculoskeletal health are tied into the overall health of the individual. The other systems of the web can influence your tendency to injure or become ill: for example, stress hormones that result from heavy exercise training or lifestyle pressures can hugely impact on an individual’s body systems. Secondly, certain biochemical processes can influence these systems – processes in the body that deserve special attention in this regard are oxidative stress and inflammation. If we can provide balance through sensible nutritional and lifestyle choices, would we gain a more speedy recovery from heavy training loads?
Before all athletes give up training in the fear of growing old very quickly, it is pertinent to mention some relevant research. A strong correlation has been demonstrated between an athlete’s maximum volume of oxygen that he/she can use and levels of the enzyme antioxidant superoxide dismutase,2 showing that exercise training increases antioxidant capacity.
Additionally, a 16-week walking programme in elderly men increased total antioxidant and glutathione peroxidase levels.3 Researchers believe that the lowest free radical load would be during a moderate exercise programme. The field of exercise immunology has also noticed a similar relationship between training load and upper respiratory tract infections (URTIs),4 which makes sense given the observed connection between free radical load and infection. As shown in Figure 1, the lowest incidence of URTIs is during a moderate training programme and this incidence increases with either a sedentary lifestyle or with heavy training loads.
Inflammation is also a normal and vital part of the human physiology. Local tissue inflammation can result from a sports injury, either acute or due to overuse, whereas systemic inflammation may be due to infection, toxicity, excessive stress, immune hyper-responsiveness (in the case of allergy or autoimmunity), dysglycaemia (abnormalities in blood glucose levels) and oxidative stress.5 For example, oxidative damage can occur on cell membranes and genetic structures (DNA/RNA), which will lead to an inflammatory response.5 Inflammation and oxidative stress are therefore intimately connected.
The inflammation and oxidative stress partnership
Inflammation (and the accompanying oxidative stress) is essential in exercise training otherwise we would stay stagnant with regard to fitness and performance. Tissue breakdown is part of a training adaptation prior to building up to new levels of tissue strength. A good analogy is a garden fence made from thin wooden posts. A strong wind picks up one day and blows it over. You then rebuild it with thicker posts, which now last a lot longer. However, one day a severe storm knocks this fence down. It is then rebuilt with even thicker posts, and so on. Training deliberately causes microtrauma to your tissues, which will then (via inflammation), be rebuilt to stronger and more adapted levels. The moment you stop challenging your tissues in training, you stop progressing as an athlete.
This simple observation calls into doubt the whole concept of ‘anti-inflammatory’ measures: ice baths, ice packs, anti-inflammatory drugs (non-steroidal anti-inflammatories) and possibly even ‘natural nutrients’.
So we need these systemic processes to adapt. There has to be a limit though – if inflammation and oxidative damage are excessive, your training increments may slow down. For example, if you push the training a notch too far, or if your body doesn’t have the necessary resources to swiftly recover, instead of only waiting two days before your next hard session, it might be three days before the stiffness and lethargy leaves your muscles.
Since establishing that inflammation and oxidative stress are integral parts of the training adaptation and that modulation (balancing) of the processes is more important than inhibition, let’s look at strategies that are available to help us strike a balance.
SUPPLEMENTS TO SUPPORT RECOVERY
Given the above discussion, antioxidants are a sensible choice of supplement for recovery from exercise and they have been well studied.
In 1993, Karlsson and colleagues worked with the Swedish Cross Country Skiing team.1 Like many endurance athletes, the skiers had been following a high-carbohydrate, low-fat approach and most were deficient in the fat-soluble vitamins, tocopherol (vitamin E) and ubiquinone (CoQ10). Skiers were supplemented with 100 mg/day of CoQ10 and 700 mg/day of vitamin E for two to three months. For those who achieved plasma CoQ10 levels of >1.1 mg/l (milligrams per litre) the number of days missed from training due to illness was reduced three-to-five-fold in the major competition months compared to skiers with <0.8 mg/l. Additionally, in a separate study, South African researchers observed that 600 mg/day of vitamin C reduced incidence of URTIs by 35% in runners who completed the ‘Two Oceans’ 56 km ultramarathon.6
In terms of muscle damage, vitamin C supplementation has been associated with a reduction in delayed onset muscle soreness (DOMS) after eccentric exercise,7 but with prolonged DOMS in another investigation.8 The reason for this anomaly is unclear and more research is certainly required to clarify the question. However, an interesting theory proposed by the later investigators8 was that a certain amount of oxidative stress is required for rapid tissue repair after exercise and that excess antioxidant use may inhibit the process. In other words, we don’t want to impede the breakdown process too much by blocking oxidation.
Amino acids and protein
Similar observations have been made in the field of amino acid research.9 While the importance of protein (especially branch chain amino acids10) is being recognised with regard to training adaptations and control of stress hormones, it has also been suggested that some degree of protein degradation is critical for muscle remodelling and repair. In this case, suppression of protein breakdown via amino acid supplementation may be inappropriate.9
Fatty acids, herbs and enzymes
On another topic, common anti-inflammatory supplements that may be used by training athletes include omega-3 oil, the herbs ginger, garlic, turmeric and boswelia, digestive enzymes such as bromelain and papain and, rather appropriately, antioxidants.5 Research has not yet queried the use of these products, but perhaps it will in time.
These theories are in their infancy, so it will take a few years for scientists to agree upon optimal supplementation strategies for recovery from exercise. Both sides of the argument make perfect sense:
- limit tissue damage during exercise to speed up later recovery and
- allow tissue degradation to potentiate the following training response (this process is known as ‘supercompensation’).
If you look at these two opposing views logically though, it would be helpful if athletes experience some degree of tissue breakdown and are still able to cope with a daily training regimen – perhaps the middle line is the best choice?
SPORTS NUTRITION IN A NUTSHELL
In sports nutrition, athletes and coaches are often obsessed with nutritional intakes that will result in a performance increment (i.e. ergogenic). Looking at the research evidence, though, only a handful of supplements (such as creatine and caffeine) can claim the label of being ergogenic. Nutrients, such as vitamins and minerals (including antioxidants), amino acids and fatty acids are not likely to boost an athlete’s performance unless there is a systemic deficiency in that nutrient. Deficiency may result from inadequate intake from the diet (like Karlsson’s skiers), limited digestion and absorption or elevated metabolic need. Perhaps a policy of supporting athletes with a sufficient supply of nutrients that are involved in the recovery and repair processes is what we need. Deficiencies can be screened for by laboratory tests such as serum vitamins and minerals, essential fatty acids, amino acids and organic acids. Additionally, experienced practitioners can often pick up the signs of nutrient deficiencies and guide athletes to appropriate dietary and supplemental strategies.
Inflammation and oxidative stress modulating diets are high in fibrous vegetables and fruits, essential fatty acids (nuts, seeds and fish), moderate in animal protein, wholegrains and starchy vegetables and low in refined sugars, grains and oils, saturated fats, caffeine and alcohol.
Make good use of post-exercise smoothies: slip in one or two teaspoons of red berry powders, or superfoods such as baobab and camu camu, which are naturally high in antioxidants; just not as high as the isolated vitamin alternatives.
This systemic approach to recovery and repair would be a good start for athletes who often focus more on the heavy carbohydrate and protein sources. In addition, moderate use of some of the above mentioned nutritional supplements is likely to be supportive to athletes who are pushing the boundaries of their bodies, whether they are professional sports people or indeed just weekend warriors with a stressful workload.
- Karlsson J. Antioxidants and Exercise. Champaign, IL: Human Kinetics, 1997.
- Jenkins R et al. The relationship of oxygen uptake to superoxide dismutase and catalase activity in human skeletal muscle. Int J Sports Med. 1984; 5:11-14.
- Fatouros I et al. Oxidative stress responses in older men during endurance training and detraining. Med Sci Sports Exerc. 2004; 36(12): 2065-2072.
- Nieman D, Exercise, infection and immunity. Int J Sports Med. 1994.
- Institute for Functional Medicine, Nutritional Management of Inflammatory Disorders. Metagenics, 1998.
- Peters E et al. Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runners. Am J Clin Nutr.1993; 57:170-74.
- Bryer S & Goldfarb A. Effect of high dose vitamin C Supplementation on muscle soreness, damage, function, and oxidative stress to eccentric exercise. Int J Sport Nutr Exerc Metab. 2006; 16:270-280.
- Close G et al. Ascorbic acid supplementation does not attenuate post-exercise muscle soreness following muscle-damaging exercise but may delay the recovery process. Brit J Nutr, 2006, 95:976-81.
- Tipton K. Protein for adaptations to exercise training. European Journal of Sport Science. 2008; 8(2): 107-18.
- Tarnopolsky M. Protein and amino acid needs for training and bulking up. Chapter 5 – Clinical Sports Nutrition 2ndEdition. Edited by Burke & Deakin. New York, NY: McGraw Hill Publishing, 2000.