Beyond Training: The Functional Medicine Edge in Athletic Performance

Do you sometimes wonder what to do to nudge your athletic performance? I focus on mastering the fundamentals before spending money on supplements, which are just optional extras.

I cannot reiterate enough the importance of recovery and sleep. This is often the weak link in the amateur athlete’s “toolkit”. Optimising sleep hygiene and recovery can make a huge difference and is most often an easy fix, unless you are working shifts and frequently travelling through different time zones, in which case there are specific hacks to employ.

Whilst working on your sleep and recovery, dialling in your nutrition and hydration is the next key factor. You need to be realistic as to what is achievable, and how far you want to take this element of performance. If you were an Olympic athlete, this would be totally dialled to an accuracy of over 99%. Most people would struggle to maintain a dietary regime with such strict protocols, so you need to ask yourself the question — how much am I willing to do to make the difference? If you are someone that enjoys a drink at the weekends or perhaps even more often, then you need to be totally honest and accept that you are not willing to sacrifice the last mile to optimise your nutrition, and sleep for that matter. That's fine, but don't think costly supplements will make up for it. 

What defines optimal nutrition?

Firstly, there is no one-size fits all. But there are some fundamental basics that need addressing. Naturally we need to get our energy intake as accurate as possible, whether for maintaining weight, losing weight or gaining weight. Once the daily energy intake is established, this can then be managed on a weekly basis to allow for different training loads across the week. The macronutrients can then be calculated to fit into this equation with protein intake remaining the same irrespective of training load. This is to ensure lean body mass is not compromised in any way. Protein intake also needs to be distributed throughout the day and may require supplemental protein sources e.g. whey protein isolate shakes, when food sources alone do not meet daily protein requirements of around 2g/kg body weight. Besides protein intake, creatine and the amino acids glycine, arginine, and methionine delivered as phosphocreatine aids in energy metabolism by donating a phosphate group in the recycling of ADP to ATP; the ultimate fuel for our mitochondria and cells. Small amounts of creatine are made in the liver and stored in muscles, however supplementation of around 5g/day, more than we make a day, has performance benefits not only for athletes but also for cognitive function.  It is a very safe product to use, being used in clinical settings for brain injuries at much higher doses. 

Once protein requirements are met, the remaining energy intake is then made up of fat and carbohydrates. Fat is an important part of the equation especially in the form of healthy fats e.g. from avocados, nuts and seeds, as well as from oily fish. The latter provides omega three oils which are essential for optimal health. The athletic specific impact of consuming higher doses of omega fish oils (3g/day) includes improved membrane fluidity which in turn enhances insulin sensitivity and glucose uptake in muscle cells. This supports energy metabolism during exercise. It also optimises calcium signalling, which is critical for muscle contraction and recovery, potentially improving strength and endurance.

Carbohydrates make up the remainder of the energy intake and include those consumed during training. Easily digestible and assimilated carbs are key during training especially high intensity bouts of exercise. Until relatively recently it was thought that the threshold dose for carb uptake and assimilation for oxidisation as a fuel was in the region of 60-90g per hour.  However, current research is looking at doses exceeding 200g/hour and even up to 300g/hour. This research has highlighted the importance of gut adaptation and that it is essential for higher doses to be gradually introduced to prevent gut distress, ie. diarrhoea and vomiting.

Besides the training carbs consumed, those consumed in meals, should be more complex from natural sources including a wide variety of starchy carbs e.g. potatoes, rice, pasta, bread, oats, millet, barley. In addition, a wide variety of colourful vegetables and fruits provide high nutrient dense predominantly carbohydrate foods, delivering an abundance of essential micronutrients, phytonutrients and fibre to support the gut microbiome. Increasing awareness of the importance of gut health has emerged in the last decade, and providing nutrients to support the beneficial microbes that live inside out gut is now understood to be more important than consuming probiotics (the actual bacteria themselves). The bacteria thrive on a wide diversity of fibres and phytonutrients that plants in our diet provide. And those bacteria in turn produce compounds that feed the cells of our gut keeping them healthy.

Hydration is essential for health altogether. Being just 1% dehydrated can have a impact on performance, not only physically but also cognitively. Being 5% dehydrated leads to an increase in core body temp of ~1–2°C risking heat stress. Reduced blood volume leads to higher heart rate, with up to a 10–20% increase, and lower oxygen delivery to muscles.  Decreased sweat rate with impaired cooling.  Noticeable fatigue, dizziness, headache, reduced coordination in addition to impaired digestion and nutrient absorption. Water alone is not enough, adding electrolytes is critical. Sodium, potassium, magnesium, and calcium are essential for nerve signalling, muscle contraction, and maintaining fluid balance. They’re lost through sweat during exercise, and imbalances can impair performance or cause cramps. Electrolyte intake is very individual, sweat rates and electrolyte sweat losses, plus ambient temperature plays a significant role. I therefore recommend athletes get sweat tested to determine how much fluid you lose in a given time and how concentrated your sweat is, taking the guessing out of what strength electrolyte solution to make up for your exercise bout. 

A critical element for health and performance optimisation is your vitamin D blood levels. We tend to think of vitamin D as being important for bone health, but it has far more functions. Vitamin D is considered a hormone, we can produce it in our skin with sun exposure, and this form requires conversion in the body. Some people are better at that conversion that others. Some fatty foods (vitamin D is a fat-soluble vitamin) also contain vitamin D but not in particularly high amounts. An interesting fact is that mushrooms when exposed to sunlight also make vitamin D. Therefore supplementation may be required, and a blood test can determine your blood levels and dictate the required dose to take to optimise blood levels. It is important to note that very high levels of vitamin D can be toxic, so I always recommend getting tested to determine individual requirements. 

Vitamin D influences muscle strength and power. It decreases recovery time from training by supporting muscle repair and reducing inflammation after intense exercise. Vitamin D strengthens the immune response, helping athletes ward off colds, flu, or upper respiratory infections that might interrupt training. Optimal levels may improve VO2 max and overall endurance by enhancing muscle efficiency and reducing inflammation. 

Finally, Magnesium is a mineral that is required in the body for over 300 different enzymatic reactions in the body including: 

Energy Metabolism: Facilitates ATP (energy molecule) production and activation, essential for muscle contraction and endurance.

Muscle Function: Regulates muscle contraction and relaxation by balancing calcium levels in muscle cells.

Nerve Function: Supports nerve signalling, ensuring proper muscle coordination and reaction time.

Bone Health: Contributes to bone density, working alongside vitamin D and calcium.

Protein Synthesis: Aids in muscle repair and growth by supporting protein formation.

Cardiovascular Health: Maintains heart rhythm and blood pressure, crucial for exercise endurance.

Found in green leafy vegetables, dietary magnesium rarely supplies enough for optimum athletic performance. With numerous different types of magnesium available it is important to choose the most suitable depending on what you are trying to achieve. 

Ultimately, the foundations of athletic performance begin with sleep, recovery, energy intake, and balanced macronutrients. Beyond this, a diverse diet rich in vegetables and fruits supports energy production and gut health through micronutrients, phytonutrients, and fibre. Key considerations also include maintaining adequate vitamin D, ensuring sufficient omega-3 intake, and supplementing strategically with creatine and appropriate magnesium sources. Hydration — during training, pre- and post- workouts — further underpins performance and recovery.