Supporting Health During Exercise and Training.
Exercise is an integral and essential 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 many 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) So it’s important to consider the positive impact that physical activity can have on your health, and try to incorporate this routinely into your life.
However, with people who have a very active lifestyle, serious amateur or elite athletes, the impact of intensive training on overall health also needs to be considered. Whilst exercise and training have many positive benefits (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 and health resilience; 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, as well as reduced training effects.
Oxidative Stress
In our body, oxidative stress is occurring all the time, with cells continuously producing free radicals such as reactive oxygen species (ROS), as part of normal metabolic processes (body functions). These free radicals are neutralised by an elaborate antioxidant defence system consisting of enzymes such as superoxide dismutase (SOD), 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 (our energy ‘batteries’), as well as cell repair.
This process allows the body, particularly muscle tissue, to improve performance over time. However, often our 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.
Mitochondria
Mitochondria are our energy powerhouses or ‘batteries’, 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. 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 numbers and efficient production of energy. Oxidative stress post-training can stimulate increased mitochondria production, but excessive oxidative stress leads to increased damage - inflammation and mitochondrial destruction (in terms of quantity and quality of function). This is where the use of antioxidants, to help repair and regenerate cells including the mitochondria, can be very helpful. 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 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 and this prevents recovery
Mechanisms for removal of the excess radical species are insufficient; antioxidant supplements can prevent the negative consequences of excess accumulation.
Vitamin D
Vitamin D deficiency, associated with oxidative stress in skeletal muscle, can lead to a reduction in muscle tissue, by disrupting mitochondrial function.(5)
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 subs