Beating the Heat: Tips for Hydration and Exercise in Summer

It’s Summer (supposedly) and that may mean you will be exercising in the heat, whether it be a warm sunny day in Ireland or if you plan on keeping your exercise routine intact while on holidays, or indeed if you are on a training camp for your sport.

Exercising in the heat may be a novelty, but if it is too warm, it can lead to health issues such as dehydration, sunburn, reduced performance and in extreme cases, sunstroke.

Planning ahead can help counteract the effects of heat while doing prolonged exercise.


If going abroad, it is important to acclimatise to the heat before participating in any intense form of exercise. For the first 3-5 days exercise at a low intensity and usually for a shorter time period. Gradually increase the volume and intensity of training from day 3 onwards. It can take up to 14 days to fully acclimatise but you should feel a lot better exercising in heat after 7-10 days

During this time, make sure you are adequately hydrated. The pee chart below will help you identify how well you are hydrated and if there is a need to take on additional fluids throughout the day.

Hydration and Exercise in Summer

Pre exercise

It is important to be well hydrated prior to exercise (Pee chart above). When you wake up in the morning, note the colour of your pee when going to the bathroom. The darker the colour, the more dehydrated you are. This is your cue to start sipping on water throughout the day, culminating in taking at least 500-750 ml of fluids in the 2 hours prior to your session. Take a mixture of fluids as some fluids will help you retain water more than others. Here’s a handy chart to help you make your choices.

Hydration Index

If it is very warm outside, it may be a good idea to stay in an air-conditioned room prior to starting exercise or drinking an ice slushie about 30 minutes prior to exercise. This will help lower your core body temperature.

Weigh yourself if possible. The reason for this will become clearer after exercise.

During Exercise

The first consideration is when to exercise. In very hot weather it is best to avoid exercising outside in the middle of the day when temperatures are highest.

Clothing is important in the heat. If you can wear a hat and sunglasses, light coloured loose clothing is best and make sure to put on sunscreen of an appropriate factor 20-30 minutes before exercising. While exercising for long periods it is advisable to wear a towel soaked in cold water around your neck and shoulders if possible.

Have fluids to hand while exercising and sip regularly. If you are exercising for longer than 60 minutes, it is worthwhile using a sports drink with carbohydrate in it.

Post exercise

Weigh yourself. Any drop in weight is likely due to fluid loss or dehydration. Any loss in weight will equate to drinking 1.5 times that amount of fluid over the next 2 hours to adequately replace lost fluid. For example, if you weighed 80kg before exercise but weigh 79kg after exercise, this is a 1 kg loss in fluid. To adequately replace this lost fluid, drink 1.5 litres of fluids.

Recover in a cool environment such as an air-conditioned room or in a pool.

PMC Physiotherapy Recommendation

When exercising in the heat, it is important to remember that you will not be able to exercise at the same intensity or duration you are used to until you acclimatise to the heat. This can take up to 14 days. Keeping your core body temperature from overheating is important alongside making sure you are not dehydrated. Recovery should take place in a cool environment after exercise. 

If you are interested in learning more about a customised strength and conditioning or training plan, contact us for more information. Our state-of-the-art private gym boasts a comprehensive range of free weights and machine weights, perfectly suited for both rehabilitation and personalised one-on-one strength and conditioning sessions guided by our expert physiotherapists.


PMC Physiotherapy Clinic, Unit 36, Dunboyne Business Park, Dunboyne, Co Meath

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