How to Exercise Safely During a Heatwave: 5 Workout Mistakes to Avoid

When temperatures rise during a summer heatwave, maintaining your regular exercise routine can become more challenging. Hot weather can leave you feeling tired, reduce your workout performance and increase the strain placed on your body during physical activity.

That does not necessarily mean you need to stop exercising altogether. However, it may be necessary to change when, where and how intensely you train.

Whether you enjoy running, cycling, gym workouts or outdoor fitness classes, understanding how to exercise safely in hot weather can help you stay active while reducing the risk of heat-related problems.

Here are five common workout mistakes to avoid during a heatwave, along with practical tips for staying comfortable and exercising more safely.

1. Starting Your Workout Too Intensely

One of the biggest mistakes you can make when exercising in hot weather is assuming your body can perform at exactly the same level as it does in cooler conditions.

High temperatures can make exercise feel considerably harder. Your body has to work to regulate its temperature while also supporting physical activity. As a result, your usual pace or workout intensity may feel much more demanding.

Instead of immediately pushing yourself, begin your session gradually. Spend additional time warming up and allow your heart rate to increase progressively.

You may also benefit from reducing the intensity or duration of your workout during particularly hot days. For example, a long outdoor run could be replaced with a shorter, easier session, while a high-intensity workout could be modified to include longer recovery periods.

Personal trainer Luis Tibbles, co-owner of Tibbs Fitness and head coach at FLATOUT, recommends avoiding the assumption that you can maintain exactly the same performance level in significantly higher temperatures.

The key is to pay attention to how your body responds rather than focusing exclusively on your usual pace, distance or workout targets.

2. Exercising During the Hottest Part of the Day

Timing can make a significant difference when exercising during a heatwave.

In the UK, extremely hot conditions can make outdoor workouts particularly uncomfortable during the middle of the day. Temperatures are often at their highest during the afternoon, which can increase the amount of heat your body has to manage.

If possible, consider exercising early in the morning or later in the evening, when temperatures are generally lower.

Morning workouts can be a good option, but preparation still matters. If you plan to exercise early, make sure you have been drinking enough fluids beforehand and give yourself enough time to hydrate after waking.

It is also important to remember that heat tolerance varies between individuals. Someone who regularly lives and trains in a hot climate may be more accustomed to exercising in high temperatures than someone who is not.

Your personal fitness level, age, health, acclimatisation and the type of exercise you are doing can all influence how you respond to heat.

3. Waiting Until Your Workout to Think About Hydration

Hydration should not begin when your workout starts.

If you arrive at an exercise session already dehydrated, drinking water during the workout may not immediately compensate for the fluid you have lost.

During hot weather, make hydration part of your daily routine. Drink fluids regularly rather than waiting until you feel extremely thirsty.

The amount of fluid an individual needs can vary depending on factors such as body size, activity level, temperature, diet and how much they sweat. People exercising for longer periods or sweating heavily may also need to consider electrolytes.

However, there is no single hydration target that is appropriate for everyone. Drinking excessive amounts of water can also be harmful, so avoid forcing yourself to consume large quantities unnecessarily.

For longer or particularly sweaty workouts, an appropriate electrolyte drink may be useful, especially when substantial fluid and sodium losses occur through sweating.

The simplest approach is to plan ahead. Drink regularly throughout the day, take fluids with you when exercising and consider how long and intensely you expect to train.

4. Eating Immediately After a Hard Workout in Extreme Heat

Nutrition remains important during hot weather, but your immediate priority after a demanding outdoor workout may be cooling down and replacing lost fluids.

For example, after completing a long run in high temperatures, your heart rate and body temperature may remain elevated for some time.

Rather than immediately sitting down for a large meal, allow yourself a short period to cool down and recover. Move somewhere cooler, gradually reduce your activity and begin replacing fluids.

Once you feel more comfortable and your body has started returning toward its normal temperature, you can focus on eating a balanced recovery meal or snack.

That does not mean you should avoid food after exercise. Your nutritional needs still matter, particularly after longer or more demanding sessions. Instead, think about recovery as a process involving cooling, hydration and nutrition rather than focusing on food alone.

5. Ignoring Signs That Your Body Is Struggling

Perhaps the most important rule when exercising during a heatwave is to listen to your body.

Feeling unusually dizzy, nauseous, weak or faint during exercise should not be treated as something you simply need to push through.

If you begin feeling unwell, stop exercising and move somewhere cooler. Sit or lie down if necessary and allow yourself time to recover.

Heavy sweating can be a normal response to exercise in hot conditions, but concerning symptoms should never be ignored. Confusion, fainting, severe weakness or a significant deterioration in your condition can indicate a potentially serious heat-related illness and require urgent attention.

It is also important to exercise with someone else when conditions are particularly challenging, especially if you are planning a long outdoor session. Letting someone know where you are going can provide an additional safety measure.

How to Exercise Safely During a Heatwave

You do not necessarily have to abandon your fitness routine when temperatures rise. Instead, consider adapting it.

A few simple changes can make hot-weather exercise more manageable:

• Exercise during cooler parts of the day.
• Reduce workout intensity when necessary.
• Take more frequent breaks.
• Drink fluids regularly throughout the day.
• Wear lightweight, breathable clothing.
• Choose shaded routes when exercising outdoors.
• Consider indoor exercise when outdoor temperatures become excessive.
• Give yourself additional recovery time.
• Stop if you develop concerning symptoms.

Most importantly, do not feel pressured to achieve the same performance you would expect in cooler weather.

A temporary reduction in intensity does not mean you are losing progress. For some people, maintaining fitness during extreme heat may be a more sensible goal than attempting to increase performance.

Final Thoughts

Exercising during a heatwave requires a little more planning and flexibility. Starting too quickly, exercising during the hottest part of the day, neglecting hydration and ignoring warning signs can all make workouts unnecessarily difficult or potentially unsafe.

Instead, adjust your expectations, prepare before exercising and pay attention to how your body feels throughout the session.

As Tibbles points out in the source material, people respond differently to heat. Some may tolerate high temperatures relatively well, while others may need to reduce their training intensity significantly.

The goal should not be to prove that you can exercise through uncomfortable conditions. The goal is to remain active in a way that respects your body's response to heat.

When temperatures are unusually high, knowing when to slow down, change your workout or take a rest day can be just as important as completing the workout itself.

Source

The Independent on 7 August 2026.

Disclaimer

This article is intended for general informational purposes only and should not be considered medical advice. Individual responses to heat and exercise can vary considerably. If you have an underlying health condition, take medication that may affect your response to heat, are pregnant, or have concerns about exercising in hot weather, speak with an appropriate healthcare professional before changing your exercise routine. If you develop serious symptoms while exercising in the heat, seek urgent medical assistance.