How women can beat the heat

How women can beat the heat when training

For all our super sweaty betty’s out there, this one’s for you! You might notice some days you’re better at dealing with heat than others, or you just downright hate humidity. You are not alone, training and performing in humidity can be tough, then add in the impact of hormones and you’ve got yourself a pretty spicy concoction. There are ways to mitigate humidity through hydration as well as hormonal impact so you can perform well whatever the weather. So let’s get into it!

Sweat rate and hormones

When running on a hot and humid day it is important to consider how the temperature could impact both your sweat rate (how much you are sweating during running) and more importantly, how you will replace fluids and electrolytes lost during exercise.

Sweat rate varies between individuals and factors such as your body mass, fitness level, gender (men in general sweat more than women), your genetics and also hormones. During your menstrual cycle hormonal changes could impact your sweat rate. In particular, the presence of Progesterone in your Luteal Phase (the day after ovulation through to the first day of your period, usually ~14 days) can increase your core body temperature and heart rate. That might make training in the heat a little more challenging than normal.

When Oestrogen is highest, during your Follicular Phase (as your period ends through to the day of ovulation, usually day ~7-14 of your cycle), your body is better at temperature regulation and your sweat loss during exercise occurs at a lower temperature meaning you are more effectively cooled down (as sweating is the body's way of cooling itself down and regulating your temperature).

It is also worth noting that during perimenopause women might struggle with temperature regulation, have a change in sweat rate with exercise and find training in the heat more uncomfortable as fluctuations in sex hormones impact all of the above.

Hydration requirement

With sweat rate being so variable how are you to know your hydration requirements? There are several guidelines and opinions on estimating fluid needs for exercise but for most people using the target of 500-900 mls per hour of exercise is appropriate. You may have heard of weighing yourself before and after exercise to assess your hydration status. You want to try and limit change in body weight to less than 2% as this means you have nailed your hydration target.

You also need to make sure that you are nailing hydration across the day, not just when exercising. Your baseline requirements for fluid are between 2-3 litres per day and it is best to try and spread this evenly across the day. If you are living or training in warmer climates then I would be aiming for the upper end of that range, closer to 3 litres per day.

Should you use electrolytes or just water? If training for 60 minutes or less, water is just fine. For longer sessions I would recommend using Electrolyte fluids or tablets which can be added to water. Electrolyte drinks contain water, glucose (carbohydrate) and minerals such as sodium, potassium, magnesium and calcium. We lose electrolytes in sweat when we are training and this can cause symptoms such as poor performance, fatigue and cramping if not replaced. This is because mineral salts such as calcium and potassium are involved in the process of muscle contraction and nerve pathways. Electrolytes are also important as they actually help in the process of keeping us hydrated by pulling water from our intestines into our cells.  

Some general tips for nailing hydration when training in warmer climates:

• Start hydration early into a run, as early as 15 minutes in
• Take small sips often, such as every 15 minutes, rather than consuming larger volumes at once
• Keeping your fluids cool (freezing or adding ice into hydration bladders for example) can also be a good idea as it is refreshing and therefore might encourage you to drink more