Exercise is an essential and integral part of a healthy and optimal lifestyle. The benefits of exercise are extremely well documented with overwhelming evidence that lifelong exercise is associated with an increased health span, delaying the onset of forty chronic conditions and diseases.1
One of the main reasons for this reduction in chronic disease is that habitual physical activity stimulates anti-inflammatory pathways. One study demonstrated that physically inactive middle-aged women (engaging in less than one hour of exercise per week) experience a 52% increase in all-cause mortality, a doubling of cardiovascular-related mortality, and a 29% increase in cancer-related mortality when compared with physically active ones.2 Therefore it is essential to consider the impact physical activity is having on a client’s wellbeing and incorporate this into their therapeutic plan.
On the other hand, when supporting clients who have a highly active lifestyle or are in fact elite athletes, the impact of intensive training on overall wellness needs to be considered. Whilst exercise and training have multiple benefits to health including: improved muscle mass and function, cardiovascular function, blood sugar regulation and respiratory health; excessive amounts of training are associated with an increase in oxidative stress, cortisol and inflammatory markers as well as a depression of immunity post-training. These factors in short doses aid improvements in performance, however, in excess, and if recovery is insufficient, they can contribute to long term damage and immune suppression, including disruption to the gut microbiota, leading to injury and infections. In this blog we discuss physiological factors which are affected by training and interventions which can support a healthy recovery from training.
Oxidative stress is occurring all the time in our bodies, cells continuously produce free radicals such as reactive oxygen species (ROS) as part of metabolic processes. These free radicals are neutralised by an elaborate antioxidant defence system consisting of enzymes such as catalase, superoxide dismutase, glutathione peroxidase, and numerous non-enzymatic antioxidants, including vitamins A, E and C, glutathione, ubiquinone, and flavonoids. As exercise increases metabolic turnover it can lead to an imbalance between ROS and antioxidants, and therefore an excess of oxidative stress.3 A certain amount of oxidative stress is important for cellular regeneration allowing for rebuilding of mitochondria in particular as well as cells. This process allows the body, particularly muscle tissue, to improve performance over time. However, often antioxidant systems can become overwhelmed if there is i) too high a level of oxidative stress ii) reduced intake or production of antioxidants and/or iii) there are insufficient recovery periods in-between training sessions.
A study which investigated the relationship between oxidative stress and exercise recommends oxidative stress status monitoring followed by appropriate use of antioxidants as a part of the training regime.4
An interest in studying the effects of antioxidant supplementation on exercise performance and recovery is based on the following:
- Mitochondrial adenosine triphosphate (ATP) production is not 100% efficient, so that superoxide radicals are formed in increased quantities during exercise. The more oxygen utilised during exercise, the more superoxide radicals are formed that need to be quenched
- Muscle damage results in excess free radical production during the secondary phagocytic phase and this prevents recovery (the secondary phagocytic phase is chemotaxis, or movement towards chemical stimulus, of phagocytes following activation after damage to muscle)
- The endogenous mechanisms for removal of the excess radical species are insufficient and antioxidant supplements should prevent the negative consequences of excess accumulation
As we know, mitochondria are our energy powerhouses and are essential for all functions that occur in the body. When training, the requirement for mitochondria is increased due to an increased need for energy output. Therefore supporting mitochondrial function is considered to be of importance for maintaining and improving performance and recovery. Mitochondrial biogenesis (synthesis of new mitochondria) is constantly ongoing within skeletal muscle in order to maintain mitochondrial content and function in response to various stimuli including exercise, as well as other cellular stressors and oxidative stress post-training stimulates increased mitochondria production. However excessive oxidative stress leads to damage and thus antioxidants are supportive, although not in excessive doses (above recommended dosage levels).
Mitochondrial DNA (mtDNA) is more readily exposed to damaging free radical species due to its close proximity to the electron transport chain, along with the lack of protective proteins that nuclear DNA possesses. mtDNA damage ultimately reduces the quality and quantity of mitochondrial biogenesis in muscle, further supporting the need to provide antioxidant support.
In one study of equine athletes, supplementation with selenium demonstrated beneficial effects on mitochondrial biogenesis during growth and training, however the study concluded a more strenuous exercise training protocol should be investigated to determine the potential benefits of elevated dietary selenium for elite equine athletes.5
Vitamin D deficiency is associated with oxidative stress in skeletal muscle and increases atrophy by disrupting mitochondrial function.6
Importance of Sleep
Sleep is an essential part of the recovery process and critical to improve training capacity and ultimately performance.
Post-exercise recovery is vital for all athletes. If the balance between training stress and physical recovery is inadequate, performance in subsequent training sessions or competition may be adversely affected. In addition it can become a vicious cycle as muscle fatigue or soreness may adversely affect sleep, with inflammatory cytokines linked to disruption of normal sleep. Sleep deprivation is associated with increased catabolic and reduced anabolic hormones which results in impaired muscle protein synthesis, blunting training adaptations and recovery.7
Nutrients such as tryptophan, magnesium, vitamin B6, glycine, L-theanine, and natural sources of melatonin can support restful sleep. Sleep can be promoted either by inhibiting wake-promoting mechanisms or by increasing sleep promoting factors through nutritional interventions. Based on one review of the existing scientific literature, there appears to be considerable scope for further investigation of nutrition interventions designed to enhance sleep quality and quantity or promote general health, sleep health, training adaptations and/or recovery in both general and athletic populations.7
Nutrients to Support Muscle Health
During exercise, muscle fibres are broken down and re-built and this is part of the anabolic process by which muscle mass is increased. Mitochondrial function is therefore essential for this as the process requires significant amounts of energy. It is also important that the body has sufficient intake of the building blocks needed to increase muscle mass. Nutrients important for new muscle synthesis are:
Omega-3 Fatty Acids
Incorporation of omega-3 fatty acids into cellular membranes which aids cell membrane health and fluidity as well as inducing changes to phospholipid species used as substrates for various signalling cascades is the main way in which they impart beneficial effect on muscle health and mass. They are capable of reducing systemic inflammation by inhibiting the release of pro-inflammatory cytokines from immune cells and improving the signalling efficiency of proteins that are involved in growth and hypertrophy. Research shows supplementation dosages ranging from 2 to 5g/day for a minimum of four weeks results in improvements in anabolic signalling efficiency and muscle strength outcomes.
In vitro studies have shown that the omega-3 fatty acids EPA and DHA exert anti-lipotoxic and anti-cytotoxic properties during myogenesis (muscle growth) and can increase satellite cell (precursors to skeletal muscle cells able to give rise to further satellite cells or skeletal muscle cells) activity post exercise. Therefore supplementation with omega-3 fatty acids may support muscle growth and recovery, particularly post-exercise.8
It is well known that magnesium is responsible for muscle relaxation and therefore muscles use significant amounts of magnesium in order to maintain normal function. Animal studies indicate that magnesium might improve exercise performance via enhancing glucose availability in the brain, muscle and blood; and reducing/delaying lactate accumulation in the muscle. Other studies have shown a positive association between magnesium status and muscle performance, including grip strength, lower-leg power, knee extension torque, ankle extension strength, maximal isometric trunk flexion, rotation, and jumping performance. Additionally, findings from intervention studies showed that magnesium supplementation might lead to improvements in functional indices such as quadriceps torque.9
Other nutrients that may be useful:
D-Ribose – data has shown promise for ribose supplementation leading to enhanced restoration of ATP levels following exercise, but this has seldom translated into increased athletic performance. However, as with many ergogenic aids, additional research is needed to clarify its value as a supplement. D-ribose supplementation resulted in maintenance in exercise performance, as well as lower levels of rate of perceived exertion and creatine kinase (which is elevated after muscle damage).10
L-Arginine – is the main precursor of nitric oxide via nitric oxide synthase (NOS) activity. Arginine’s involvement as a precursor of creatine and its potential to increase endogenous growth hormone makes it a popular supplement among those who wish to improve their physical performance. In patients with specific cardiovascular issues (congestive heart failure, healed myocardial infarction, and pulmonary hypertension) ingesting arginine (3–9g/day) demonstrated an improvement in physical performance.11
Post-exercise immune suppression
When performing significant amounts of exercise, as an amateur or elite athlete, it is important to support immune health as demanding exercise has been shown to depress the immune system, putting individuals at a higher risk of infections particularly of the upper respiratory tract. This may be due to the cumulative effects of repeated bouts of intense exercise with the consequent elevation of stress hormones, particularly cortisol and anti-inflammatory cytokines (e.g. IL-6, IL-10, IL-Ira) causing temporary inhibition of type 1 T-cell cytokine production with a relative dampening of the type 1 (cell-mediated) response.12
Research demonstrates short-term suppression of the immune system following an acute bout of endurance exercise, known as the “open window” period. This window of opportunity may allow for an increase in susceptibility to upper respiratory illness. Although many studies have indicated a decrease in immune function in response to exercise, they have not all shown changes in immune function beyond two hours after the completion of exercise. Consequently failing to determine whether these immune cells numbers, or importantly their function, return to resting levels before the start of another bout of exercise.13
Supporting post-exercise immunity
Vitamin D is an essential nutrient which supports normal function of the immune system. Research has found that vitamin D insufficiency is quite pronounced among elite athletes. It is accompanied with a decrease of IFN-γ, increase of TNF-α, IL-4 and IL-6 level, and increased frequency of upper respiratory tract infections (URTI). Seasonal monitoring and correction of the vitamin D level for normalisation of cytokine profile and decrease in the occurrence of URTIs is definitely advised.15
Intensive training is associated with a reduction of the antibody secretory IgA (sIgA). It has been recommended that sIgA levels should be monitored in athletes to assess risk status for developing upper respiratory tract symptoms. Given that illness can disrupt training and performance, further research is required to better elucidate how stressors individually and collectively influence immunity and illness.16 Supporting gut health is important for the production of sIgA and therefore is a useful intervention for supporting immune health and protecting against infection.
Nutritional interventions to support athletes
- Supplement with antioxidants such as N-Acetyl cysteine, vitamins A, E and C, glutathione, ubiquinone (Coenzyme Q10), and flavonoids.
- Support immune function with beta-glucans, vitamin C, zinc and also by supporting digestive health with probiotics and prebiotics
- Support sIgA production by supporting gut health, modulating stress and using a Saccharomyces boulardii supplement (shown to increase sIgA)
- Practice good sleep hygiene techniques such as maintaining a cool, dark bedroom, routine bedtimes, and meditation/mindfulness and relaxation techniques if possible. If necessary, consider sleep supporting nutrients such as 5HTP, L-theanine, magnesium, B6 or montmorency cherry
- Support mitochondrial function with B vitamins, CoQ10 and alpha lipoic acid
- Support muscle function with omega-3 fatty acids, magnesium, L-arginine and D-ribose
- Oxidative stress increases after intensive or prolonged exercise. Whilst a certain amount of oxidative stress stimulates improved muscle function, an excess can be detrimental to recovery if not attenuated, driving muscle damage and potential for injury. Therefore supplementation with antioxidants may help to improve muscle function.
- Mitochondrial health is important for both muscle growth and recovery and is significantly affected by oxidative stress. Therefore providing nutrients that support mitochondrial health and attenuate oxidative stress may be useful for supporting athletes.
- Omega-3 fatty acids can support myogenesis (muscle growth) by incorporation into cell membranes and also by attenuating inflammation.
- Magnesium is important for muscle relaxation and studies show that supplementation might improve exercise performance via enhancing glucose availability in the brain, muscle and blood; and reducing/delaying lactate accumulation in the muscle.
- Sleep is an essential part of the post training recovery process and if there are sleep problems then these should be addressed by: practising good sleep hygiene techniques such as maintaining cool, dark bedroom, routine bedtimes, and meditation/mindfulness and relaxation techniques if possible. Consider sleep supporting nutrients such as 5HTP, l-theanine, magnesium, B6 or montmorency cherry.
- D-ribose and L-arginine are nutrients which may be useful for improving muscle function.
- Immunity can be compromised in elite athletes leading to an increased risk of infections particularly of the upper respiratory tract. There is an association with low vitamin D and sIgA status. Therefore the health of the gastro-intestinal tract and vitamin D status should be considered in clients who train intensively.
If you have questions regarding the topics that have been raised, or any other health matters, please do contact me (Helen) by phone or email at any time.
firstname.lastname@example.org, 01684 310099
Helen Drake and the Cytoplan Editorial Team
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- Vina J, Sanchis-Gomar F, Martinez-Bello V, Gomez-Cabrera MC. Exercise acts as a drug; the pharmacological benefits of exercise. Br J Pharmacol. 2012;167(1):1-12. doi:10.1111/j.1476-5381.2012.01970.x
- Urso ML, Clarkson PM. Oxidative stress, exercise, and antioxidant supplementation. Toxicology. 2003;189(1-2):41-54. http://www.ncbi.nlm.nih.gov/pubmed/12821281. Accessed May 30, 2019.
- Hadžović-Džuvo A, Valjevac A, Lepara O, Pjanić S, Hadžimuratović A, Mekić A. Oxidative stress status in elite athletes engaged in different sport disciplines. Bosn J basic Med Sci. 2014;14(2):56-62. doi:10.17305/bjbms.2014.2262
- White SH, Wohlgemuth S, Li C, Warren LK. Rapid Communication: Dietary selenium improves skeletal muscle mitochondrial biogenesis in young equine athletes. J Anim Sci. 2017;95(9):4078. doi:10.2527/jas2017.1919
- Dzik KP, Kaczor JJ. Mechanisms of vitamin D on skeletal muscle function: oxidative stress, energy metabolism and anabolic state. Eur J Appl Physiol. 2019;119(4):825-839. doi:10.1007/s00421-019-04104-x
- Doherty R, Madigan S, Warrington G, et al. Sleep and Nutrition Interactions: Implications for Athletes. Nutrients. 2019;11(4):822. doi:10.3390/nu11040822
- Tachtsis B, Camera D, Lacham-Kaplan O. Potential Roles of n-3 PUFAs during Skeletal Muscle Growth and Regeneration. Nutrients. 2018;10(3). doi:10.3390/nu10030309
- Zhang Y, Xun P, Wang R, Mao L, He K. Can Magnesium Enhance Exercise Performance? Nutrients. 2017;9(9):946. doi:10.3390/nu9090946
- Dhanoa TS, Housner JA. Ribose: more than a simple sugar? Curr Sports Med Rep. 2007;6(4):254-257. http://www.ncbi.nlm.nih.gov/pubmed/17618002. Accessed May 30, 2019.
- Campbell BI, La Bounty PM, Roberts M. The ergogenic potential of arginine. J Int Soc Sports Nutr. 2004;1(2):35-38. doi:10.1186/1550-2783-1-2-35
- Gleeson M, Bishop NC. The T cell and NK cell immune response to exercise. Ann Transplant. 2005;10(4):43-48. http://www.ncbi.nlm.nih.gov/pubmed/17037088. Accessed May 30, 2019.
- Kakanis MW, Peake J, Brenu EW, et al. The open window of susceptibility to infection after acute exercise in healthy young male elite athletes. Exerc Immunol Rev. 2010;16:119-137. http://www.ncbi.nlm.nih.gov/pubmed/20839496. Accessed May 30, 2019.
- Yuan X, Xu S, Huang H, et al. Influence of excessive exercise on immunity, metabolism, and gut microbial diversity in an overtraining mice model. Scand J Med Sci Sports. 2018;28(5):1541-1551. doi:10.1111/sms.13060
- Umarov J, Kerimov F, Toychiev A, Davis N, Osipova S. Association the 25(OH) Vitamin D status with upper respiratory tract infections morbidity in water sports elite athletes. J Sports Med Phys Fitness. May 2019. doi:10.23736/S0022-4707.19.09834-7
- Keaney LC, Kilding AE, Merien F, Dulson DK. The impact of sport related stressors on immunity and illness risk in team-sport athletes. J Sci Med Sport. 2018;21(12):1192-1199. doi:10.1016/j.jsams.2018.05.014