Visiting the Freshers’ Fair this year, as always, highlighted the sheer range of opportunities we have to stay fit. Whether signing up to try a new sport, joining a new gym or simply going for runs, there is likely a form of exercise that everyone will enjoy. There are undoubtedly many well-documented positive results of regular exercise: improved cardiovascular fitness, increased energy expenditure which can make it easier to maintain healthy body weight, and increased release of mood-boosting endorphins, to name but a few. However, recent research reveals many new, surprising and exciting effects of exercise that might just convince you to go to those free taster sessions...

“Exercising to stay fit when you’re young will likely help you to maintain the optimal functioning of your muscles much later in life”

A perfectly normal effect of ageing is the associated substantial loss of skeletal muscle mass and strength, one reason why activity and certain tasks become much harder with age. Much of this process is not preventable by any sort of intervention. For example, age-related changes in the nervous system generally lead to progressive cycles of loss and replacement of the motorneurones innervating a motor unit until eventually regenerative capacity is lost, leading to the ultimate death of denervated muscle fibres. Of course, it can be difficult to ascertain how much of skeletal muscle ‘ageing’ is due to chronological progression and how much is due to accumulating effects of other lifestyle choices and pathologies with time. For the latter, exercise can have beneficial effects on how our muscles ‘age’. For example, maintaining body fat levels within healthy ranges through exercise prevents a condition known as sarcopenic obesity, which is when increased adiposity later in life worsens muscle function. This is independent of any muscle loss. So, exercising to stay fit when you’re young will likely help you to maintain the optimal functioning of your muscles much later in life.

Whilst we may see shelves of heavily marketed bottles of kefir in Sainsbury’s, most of us probably don’t spend too much time thinking of our gut microbiota on a day-to-day basis. Our gut is estimated to contain over 100 trillion bacterial cells, with a completely distinct genome from our own, acting almost as an independent organ with key roles in physiology and pathological defence. The role of our gut microbiota in metabolism is becoming increasingly recognised, so it is perhaps unsurprising that it is intertwined with exercise too. Recent research has shed light on the crosstalk between skeletal muscle and gut bacteria. Interestingly, exercise can induce compositional and functional changes in the human gut microbiota that are reversed as soon as the exercise routine is stopped, and seem to be dependent on the body fat percentage of the individual. Based on mouse models, exercise training increases concentrations within the gut of short-chain fatty acids from the microbiome, which act as a source of energy for tissues, and have been suggested to reduce inflammation and improve insulin sensitivity. This implies that exercise can affect the metabolism of the gut microbiota and may lead to positive long-term health benefits. This extends to humans, which demonstrated that the gut microbiota and its metabolism in both lean and obese study participants changes in response to exercise, which, in turn, had positive effects in the context of the physiological adaptation to exercise, for example, by improving cardiorespiratory fitness.

“This implies that exercise can affect metabolism of the gut microbiota in such a way that may lead to positive long-term health benefits”

Finally, whilst the effects of exercise on boosting mood are relatively well-known, evidence is also emerging that both aerobic and anaerobic exercise may have beneficial effects on individuals suffering from different types of anxiety, reducing symptoms. However, further well-conducted randomised controlled trials are required to strengthen this conclusion.

A healthy level of exercise is, undoubtedly, great for our health. The benefits of exercise for our mental and physical well-being are huge, and it is likely that there are many more that have yet to be uncovered. As the new academic year begins to pick up pace, remember to take the time to take care of your health, and don’t be afraid to try something new.