Why Carbohydrates Are Essential for Female Athletes

CARBOHYDRATES FOR THE WIN

Carbohydrates is the key fuel source for exercise as it is broken down into glucose, the body’s preferred currency, and utilized by the body to provide energy. Carbohydrate is stored as glycogen throughout the body, but specifically within the liver and muscles.

It is this source within the muscle that is the most readily available energy for working muscles, releasing energy more quickly than other sources. However, this storage facility is limited. If the muscles are inadequately fuelled, it will lead to fatigue, poor performance and potentially putting you at greater risk of injury.

To give you some context, it takes around 500g of carbohydrate to have completely full muscle glycogen stores, with an additional 80g in liver glycogen, mainly used to maintain energy to the brain. The human brain utilises 120g of glucose a day. 

When muscle glycogen is at full capacity, at most this will last you around 90-120 minutes training at around 65-75% of your maximal heart rate. The quicker you go, the faster your stores will deplete. Thus, for those of you training most days, your glycogen stores are always slightly depleted. 

This helps to explain how important planning your carbohydrate intake around and during training sessions is; the amount you require will be dependent on the frequency, duration, and intensity of your training.

HARNESSING HORMONES

Hormones are chemical messengers that are made by specialist cells within endocrine glands, and they are responsible for the correct function of the body. They include a long list including Oestrogen, testosterone, insulin, growth hormone, leptin, cortisol, melatonin, and thyroid hormones, T4 and T3. All of these have critical roles to play within our body from maintaining metabolic function, to ensuring progression and adaptation from our training, optimising bone health, appetite control and regulating sleep.

Regulating and maintaining our hormonal health is central to both our health and performance. Understanding how to harness the benefits of these amazing chemical messengers allows us to meet our potential.

ENERGY AND CARBOHYDRATE AVAILABILITY

Modern society tends to encourage the message that we all need to, “Move more and Eat Less”

My question is who is this relevant to?

While small daily deficits in energy can lead to some sustainable weight loss, which may be relevant for some individuals, this messaging is definitely not applicable to anyone who is physically active.

Indeed, physiological studies have determined that the human body is biologically biased towards energy balance so in reality, we need to “Move more and Eat More” for health and performance benefits. While societal messaging continues to place a real emphasis on energy in versus energy out, when it comes to sports nutrition, we should be focusing on energy availability, and if we are being absolutely correct, carbohydrate availability. That is, the amount of energy available for biological function (brain, heart, lungs, hormones, circulation, bones etc), once the cost of movement, including daily movement and training, has been subtracted from overall energy intake.

It is important to add here that the human body has evolved to prioritise energy for movement first. This is why over time if energy intake and specifically carbohydrate intake is not sufficient to meet the individual’s needs, biological processes within the body start to slow down or stop working all together, negatively impacting health and performance. In females, one such biological system that should be monitored is changes to menstrual health.

MENSTRAL HEALTH – AN ODE TO CARBOHYDRATE

Recent studies by Danish researcher Anna Mellin have confirmed that carbohydrate availability plays a key role in hormonal regulation and menstrual health, particularly in women who are physically active.

The rise in trends encouraging fasted training and avoiding carbohydrate have left a lot of women with irregular cycles or in worst case secondary amenorrhoea – the complete absence of cycles for 3 months or more. No periods, means low to no Oestrogen which has a direct negative impact on bone health and leaves women more susceptible to injury. Guess what, low oestrogen also means low levels of all hormones within the body resulting in a wider issue across many biological systems. There is a down regulation across the whole body which turns on “energy saving”  leading to individuals holding onto more body fat, rather than losing it.

Similarly, low carbohydrate intakes have been linked to a depressed immune system, thus a higher risk of infections and illness; low production of red blood cells and thus blood iron levels and stores which has a direct negative consequence to immunity, energy levels, performance and bone health. 

While moderate exercise can support our gut microbiome, if our carbohydrate intakes are inadequate, this can lead to what is known as dysbiosis, that is a change in the gut flora within the microbiome favouring bacteria that are not beneficial to health. 

Contrary to popular press, carbohydrates are not the enemy, in fact I would go as far as saying they are essential for active women to stay healthy but to also allow for progression in their training and sport.

SO HOW MUCH CARBOHYDRATE IS ENOUGH?

Ensuring that you make appropriate choices around your training and lifestyle, will help you to maintain your training effort day after day, resulting in progression; whilst also helping to maintain motivation and encourage adaptation from your training. Studies have also shown that timing of nutrition has an integral role to play in hormonal balance, bone health and maintaining your immune system.

Over the years, carbohydrates have been classified in many ways; the most common types are simple and complex. 

• Complex carbohydrates are those including pasta, rice oats, couscous, potatoes, bread, and cereals. Simple include dairy, fruit and sugar, honey, molasses, etc. 

Those of us who exercise and train, need a mix of both. Ideally complex carbohydrates at mealtimes and then more simple options immediately before, during and after, depending on the training session.

As a rule of thumb, in sport we work on the basis that for a female who is exercising at a moderate intensity for 60-90 minutes a day, that is an effort of around 7/10, so not flat out, she will need a minimum of 5g of carbohydrate per Kg of Body weight, distribute evenly throughout the day.

EXAMPLE – TYPICAL DAY OF FUELLING

Prior to training

• Breakfast – aim to take on a carbohydrate dense choice such as bagel with peanut butter and banana or porridge with fruit and honey.

During training

• During your training, especially if it’s harder or longer (>90 minutes) you want to think about taking on no less than 40g of carbs per hour, aiming for up to 90g per hour for a longer distance. Good ways to ensure these requirements are met are to use SiS energy gel or energy drink options during harder and longer training sessions: e.g. GO Isotonic Energy gel, BETA Fuel Energy Gel or GO Energy Powder.
• Similarly, these products can also be used ahead of an early morning session to avoid doing any training in a fasted or depleted state which is never appropriate for females.

Post training

• Immediately post training, aim to recover with both carbohydrates and protein within 30 minutes for optimal recovery of glycogen stores and also muscle repair. REGO Rapid Recovery or REGO Clear Recovery is a convenient away of getting both carbohydrate and protein immediately post session.
• Follow this with a balanced meal within 2 hours, such as baked potato with tuna or eggs on toast or roasted vegetables with couscous and houmous.
• Mid-afternoon, with recovery still as your focus, choose a nutrient dense snack such as oatcakes and cheese or banana bread with peanut butter or a granola and yoghurt pot. 
• Finish up with a blanched main meal such as chickpea or chicken curry with rice.
• Depending on your day, you may need a further snack before bed.