Pre-match nerves and anxiety are part and parcel of a tennis player’s life. Whatever level you play at, you’ll no doubt have felt that nervous tension in the pit of your stomach, which to some can be disastrously debilitating, while others channel the excitement and come out on top.
The psycho-physiological aspect of tennis is one of the areas that sets it apart from other sports and understanding the physiological response of the body to stress in this sort of situation can be an asset to improving your response and your overall performance.
Our stress response is controlled by the hormones adrenaline and cortisol. The Fight or Flight mechanism helps ensure we have the energy to combat the stress of a situation, by signalling the need to break down glycogen stores or initiate the conversion of fat or protein to produce energy – where glycogen isn’t available.
For some the stress is defined as Eustress which is an excitement or euphoric state accompanied by a ‘seize the day’ attitude, while for others it is Distress – the heightened anxiety that can knock a player off their game, often seen in the early stages of a match.
However, part of that stress response has the effect of down regulating body systems that are considered less important during times of stress. Our digestive function and immune response are the two areas where this is most commonly experienced, opening up the tennis player to a range of unwanted health concerns.
When stress impacts on digestion it can have serious consequences both in terms of unwelcome symptoms, but also to the ability to absorb nutrients effectively.
Production of cortisol down regulates our secretion of Hydrochloric Acid, the main component of stomach acid.
Not only is this the first line of defence for destroying any food-borne bacteria or pathogens, but it is needed in order to release digestive enzymes which start the job of breaking down food into the molecules that will later be absorbed in the intestines.
It is also needed to help absorb specific nutrients in the stomach and to produce the carrier molecule that allows us to absorb vitamin B12 from our food – one of the main catalysts in energy production within the body.
If pathogenic bacteria reach the small intestines they can affect the balance of microflora adversely, which in turn can reduce the barrier protection to the gut wall – already compromised due to the down-regulation of the immune system. We carry around 80% of our immune antibodies in and around the digestive tract as this is actually our biggest interface with ‘the outside world’.
Cortisol down regulates our immune function so the immune antibodies that normally protect the gut and surrounding tissue from harmful bodies are reduced, leaving us more susceptible to gut-derived toxins and bacteria. This can manifest in symptoms like bloating, cramping, pain and diarrhoea. And worse still, the lack of gut defence could lead to the development of food intolerances, which can result in symptoms such as fatigue, muscle or joint pain, or brain fog to name a few.
Similarly, if the gut flora is disturbed and digestive enzymes are not being produced appropriately, the body is going to struggle to absorb the nutrients from even the most perfect diet leaving you depleted in energy and recovery nutrients.
So there are two areas to address. Firstly release of cortisol. Managing the release of the hormone on match day is more a psychological issue rather than a nutritional one. However, managing cortisol levels the rest of the time will help diminish the effects on an ongoing basis – after all, life is constantly presenting us with stress which will elicit the same reaction: busy jobs, home and family life, exam stress are just a few examples.
The most important part of the process is to ensure that you eat regularly. Skipping meals means the body has to release cortisol to break down stored energy, while eating 3 good meals and 2 snacks per day can help reduce demand.
Similarly eating a high sugar diet will cause energy dips that will see more pressure being put on cortisol release, so stick to low GI food choices: instead of processed foods, refined sugars and saturated fats choose whole-grains, plenty of fruit and vegetables and lean protein in the form of chicken, turkey or fish.
And avoid stimulants such as alcohol and caffeine – so coffee, tea and caffeinated soft drinks are out!
The second area to think about is ensuring that gut function is restored to normal. You can stimulate stomach acid production by starting the day with a cup of hot water and lemon, take a spoonful of apple cider vinegar before each meal, and include bitter foods like radish, artichokes, beetroot, lemon, garlic, ginger, turmeric and dark green or red leaves.
Beneficial gut bacteria can be supported by eating plenty of fruit and vegetables – they thrive on fibre, whereas pathogenic bacteria like to feed on sugar so cutting off their food source will help to rebalance your gut flora.
But if you still experience digestive disturbance you may need some specialist advice from a nutritional therapist or sports dietician who can organise gut function tests to understand the complete picture and help restore your gut to better health!