The Science Behind Hot Yoga

4 days ago

5 min read

Why we practise in a heated room and how to make the most of it

At Sun Connexion, we believe yoga is about understanding and respecting the body, not simply pushing it to its limits. Practising in a heated room adds another dimension to traditional Hatha Yoga, influencing our muscles, circulation, breathing and the way our body regulates temperature.

But why do we use heat? What does science tell us about its benefits? And how do we practise safely?

The origins of Hot Yoga

The practice has its roots in the Indian Hatha Yoga tradition, particularly the teachings of Bishnu Charan Ghosh. His student, Bikram Choudhury, developed the well-known sequence of 26 postures and two breathing exercises, which became popular internationally during the 1970s.

Traditional Bikram Yoga is practised at approximately 40.6°C with 40% relative humidity. The intention was partly to recreate the warm climate of India, while providing a consistent environment for the practice.

Today, heated yoga is practised in many forms, with different temperatures, humidity levels and teaching approaches.

Why practise yoga in a hot room?

Muscles and flexibility

Warmth can make muscles feel more comfortable during movement and stretching. Combined with regular yoga practice, this may help improve flexibility, balance and mobility.

However, feeling more flexible does not mean we should stretch further than our body allows. The objective is controlled movement, not forcing a posture.

Bones, joints and strength

Yoga involves supporting our body weight, holding postures and maintaining balance. These activities place controlled demands on muscles and bones.

Research suggests regular Bikram Yoga may support bone mineral density, particularly around the hips and spine, although larger studies are needed.

Importantly, these potential benefits come mainly from the physical postures and the work performed by the muscles. There is no clear evidence that heat itself strengthens bones.

Circulation and the cardiovascular system

In a heated room, the heart works harder to help regulate body temperature. Blood flow to the skin increases, allowing the body to release heat.

Repeated exposure to heat may contribute to certain cardiovascular adaptations, although research has not established that heated yoga is consistently more beneficial than practising the same postures at normal room temperature.

Sweating and detoxification

Sweating is one of the body's most important cooling mechanisms. As sweat evaporates from the skin, it helps release excess heat.

Although sweating is often associated with detoxification, the science is more specific.

Sweat consists mainly of water and electrolytes, with small amounts of other substances. The liver and kidneys perform most of the body's detoxification work.

Sweating more does not necessarily mean eliminating more toxins. The real benefit is the body's natural ability to regulate its temperature.

The mind and nervous system

Practising yoga in warmth can also be mentally demanding. Maintaining steady breathing, concentration and controlled movement encourages awareness of our physical and mental responses.

Studies suggest heated yoga may improve certain aspects of psychological wellbeing, including symptoms of depression, although further research is needed.

Temperature and humidity: finding the balance

Temperature alone does not determine how demanding a heated room feels.

Humidity plays an equally important role.

When humidity increases, sweat evaporates less efficiently, making it harder for the body to cool itself. Consequently, a room at 33°C with 90% humidity can feel considerably more demanding than a room at the same temperature with 40% humidity.

Traditional Bikram Yoga uses approximately 40.6°C and 40% humidity as its reference condition.

The graph below illustrates how different combinations of temperature and humidity compare using an approximate wet-bulb temperature calculation.

This is a scientific measure of heat and moisture in the air, not an official Bikram temperature chart or a guarantee of safe conditions. Air circulation, class intensity, duration and individual tolerance must also be considered.

Preparing for your Hot Yoga class

Hydration begins before entering the studio.

Drink water regularly throughout the day rather than consuming a large quantity immediately before class. Arriving already dehydrated makes regulating body temperature more difficult.

During class, take small drinks when needed. After class, replace lost fluids gradually. If you have been sweating heavily, normal meals or appropriate electrolyte replacement can help restore lost salts.

Avoid forcing yourself to drink excessive quantities of water, as this can also be harmful.

Wear comfortable, lightweight clothing, bring a towel and allow yourself time to adjust to the heat.

If you are new to hot yoga, take your time and enjoy the experience. Listen to your body, move at your own pace and rest whenever you need to. Simply lie down on your mat, keep your eyes open, breathe gently through your nose, take a sip of water and relax until you feel ready to join the class again.

When should you be cautious?

Everyone experiences heat differently, and it's important to approach your practice with awareness and respect for your body.

If you are pregnant, have an existing medical condition, particularly involving your heart, blood pressure, kidneys or respiratory system, or take medication that affects your body's response to heat, we recommend consulting your healthcare professional before attending.

We also encourage you to arrive feeling well, rested and hydrated. If you have a fever, are feeling unwell or have consumed alcohol, it is best to give yourself time to recover before joining a class.

Our aim is to provide a welcoming environment where you can enjoy the benefits of hot yoga while practising comfortably and at your own pace.

A note for our yogis

Your practice is personal. Some days you may feel strong, flexible and energised. Other days, your body may ask you to slow down.

Listen to those signals.

The heat is part of the environment, not a competition. There is no achievement in tolerating discomfort beyond your limits.

Progress comes from consistency, awareness and patience.

The science behind the practice

Heat changes how the body responds to exercise. It influences circulation, sweating, cardiovascular demand and our perception of effort.

But more heat does not automatically mean more benefit.

The true value of heated yoga comes from combining a thoughtful physical practice with an appropriately managed environment.

At Sun Connexion, our approach is simple: respect the tradition, understand the science and listen to the body.

The objective is not to endure the heat. It is to practise yoga with awareness, strength and balance.

With this in mind, we aim to keep the combined temperature and humidity of our studio below the reference line shown on the graph, using the traditional Bikram conditions of approximately 40°C and 40% humidity as our benchmark.

During Queensland's hot and humid summer days, conditions can sometimes approach this line. We therefore monitor both temperature and humidity throughout our classes, making adjustments as needed to maintain a comfortable and enjoyable environment for everyone.

The article draws on published research and guidance, including: