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How To Train Safely In Hot Weather

How To Train Safely In Hot Weather
Scott Whitney
Sports Therapist and S&C Professional2 years ago
View Scott Whitney's profile
Here in the UK, we’ve been experiencing some serious heat recently, and it finally feels like summer has arrived. So if you're gazing out the window thinking a HIIT session in the sun might be fun, there are a few tips to take on board.Safety should always be top priority in training, especially when training outside in the heat. What may usually be a moderate or slightly challenging run outdoors can quickly become deadly, as exercise intensity is exacerbated in extreme heat. In this article, we’ll provide advice on how to continue to train safely, ensuring your training remains practical, safe, and effective throughout these summer heatwaves.


Train Early or Late in The Day

During a heatwave, it’s likely that even the cooler times of the day will still have elevated temperatures. Training early in the morning or late in the evening will allow you to avoid the peak temperatures – when your main focus should be to avoid exposure to the intense sun for extended periods of time.


Wear Sunscreen

This one is obvious to many. If you’re going to be exercising outdoors during intense (or even moderate) sunshine, then the last thing you want is sunburn, to any degree. 

Wearing the appropriate factor of sunscreen when working out outside (or being outside in general) will significantly improve the health and longevity of your skin – the biggest organ in your body. Sunscreen not only helps to keep your skin hydrated and healthy, but it blocks UV rays that can damage the DNA in your skin cells.


Exercise Nutrition

When exercising, your body relies on having a sufficient supply of carbohydrates to get you through the session. Furthermore, micronutrients in a balanced diet are key for performing essential bodily functions, such as the roles of sodium and potassium in muscle contractions. Subsequently, we need to ensure that our body is fuelled sufficiently to carry us through our session, or else we risk undue fatigue and potentially dizziness, exacerbated by intense sunlight. 

Additionally, it remains as important as ever to ensure you provide your body with the correct nutrition to be able to repair the exercise induced muscle damage – this means, you need to be taking on enough protein for your body mass and activity level!



When exercising, it’s normal to lose body water via sweating, and increased metabolic activity in your muscles also leads to a rise in core temperature. Remaining hydrated has a significant effect on your body’s ability to regulate its temperature – known as thermoregulation, a part of homeostasis. When hydration is insufficient, your body is unable to cool itself efficiently, leading to hyperthermia – excessively elevated core temperature. Hydration levels also significantly influence athletic performance, as electrolytes are lost in sweat. The loss of fluids and electrolytes leads to more rapid fatigue of skeletal muscles, drastically hindering performance. 

Unfortunately, you cannot simply keep chugging as much water as your body can take. Doing so can lead to a condition known as hyponatraemia – referring to having low levels of sodium in the blood. This is because ingesting too much water can make your body hypervolemic, meaning you now have an excessive water to sodium ratio in your body. This changes the osmotic gradient in your body, allowing water to flood into cells – leading to symptoms such as swelling, nausea, and even seizures to name just a few symptoms. 

The colour of your urine is one of the best indicators of your hydration levels. Charts showing normal and abnormal colouring should be used as a guide. Additionally, how you feel is a good indicator – if you feel tired and fatigued in the middle of the day, it’s likely that you need to rehydrate. Finally, knowing your normal body mass is helpful, as you can then use this as a guide to somewhat replace body mass lost through sweat. 

The use of isotonic sports drinks can help to hydrate and also re-balance electrolytes lost via sweat, mitigating the risk of muscle cramps.


Dress for the Weather

Wearing light coloured clothing that is breathable is the best way to dress when exercising in the heat, particularly when outdoors. Dark coloured clothing absorbs more light, meaning you will get hotter, while light coloured clothing reflects more of the sunlight that hits it, minimising the amount of heat absorbed by you. 

Of course, UV-blocking sunglasses and high SPF sunscreen will help to protect your eyes and skin. This is important to remember since sunburn limits your body's ability to regulate its temperature and remain cool. 

Check out MP clothing to get kitted out for the summer.

Be Aware of The Symptoms of Heat Exhaustion and Heat Stroke

One of the reasons for this is due to a lack of hydration, leading to a lower fluid volume to carry oxygenated red blood cells efficiently to the brain. This is what causes symptoms of heat exhaustion such as fainting, headaches and dizziness. 

The main symptoms of heat exhaustion are as follows: 

  • Dizziness 
  • Headache 
  • Fainting 
  • Nausea or vomiting 
  • Dark urine 
  • Cool, moist skin 
  • Heavy sweating 
  • Muscle cramps 
  • Fatigue 
  • Weakness 

When these symptoms occur, it is vital that you address them immediately, or else they may progress to a more serious condition known as heat stroke. This includes symptoms such as: 

  • Core temperature of above 39°C 
  • Seizures 
  • Unconsciousness 
  • Dry, hot skin (no sweating) 
  • Rapid, weak pulse 
  • Confusion
Treating heat stroke will again depend on rehydration and cooling of the affected individual, although a person with heat stroke is likely to need to visit the hospital.


Take Home Message

Many of us will want to continue to maintain our fitness and keep hitting PR’s, even during heatwaves. When doing so, it is important to take all of the relevant precautions, to avoid adverse effects that could result in harm, or even death. If the heat becomes too much, then do not feel obligated to do your session anyway – it’s okay to take a day off! Overall, it is important to know your own limits!
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Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you're concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.

Scott Whitney
Sports Therapist and S&C Professional
View Scott Whitney's profile
Scott developed a passion for sport and performance through competing in long‐distance running and bouldering prior to attending university. Scott’s academic achievements include a BSc honours degree in Sports Therapy and an MSc degree in Strength and Conditioning. He is also a member of The Society of Sports Therapists and CIMSPA. Previously, he has worked with amateur and elite athletes, ranging from university sports teams to elite rugby league athletes and Team GB rowers. He currently works with various gyms in developing and delivering training programmes for amateur athletes and gym‐goers. While passive treatments remain in his arsenal as a Sports Therapist, Scott uses his skills to promote physical activity for combatting obesity, lower back pain and other sporting injuries, and simultaneously providing programmes for athletic development. Being a recent graduate, Scott strives to gain experience wherever possible, offering advice and sharing knowledge along the way. He believes it is important to practice what you preach, so in his spare time, Scott practices Olympic Weightlifting and enjoys being active outdoors in all weathers, although he still believes it is important to make ample time for social activities.