RecruitingNAINTERVENTIONAL

Effects of Exercise Timing on Sleep Quality

This study aims to understand if the time of day you exercise affects your sleep, particularly your deep sleep. Researchers are comparing two groups: people who are very fit endurance athletes, and people who don't exercise regularly. They want to see if exercising in the late afternoon might make it harder to get good deep sleep, especially for those who are less active. This is because late exercise can sometimes raise your body temperature, which might interfere with your body's natural sleep processes. The study will measure things like how quickly people fall asleep, the quality of their deep sleep, and their body temperature, to learn if morning exercise is better for sleep than late afternoon exercise, and if this differs between active and inactive people.

At a glance

Status

Recruiting

Phase

Sponsor

Centre Hospitalier Universitaire de Saint Etienne

Enrolment target

Start

23 Jan 2026

Estimated completion

31 May 2029

Healthy Endurance Athlet Inactive People

What is this study about?

Many of us know that regular exercise is good for our health. However, some people wonder if the time of day they exercise matters, especially when it comes to sleep. This study is designed to explore just that. We're looking at whether exercising in the morning compared to the late afternoon affects how well people sleep.

The main idea is that exercising late in the day might raise your body temperature. For some people, especially those who aren't very active, this rise in temperature could make it harder for their body to cool down and get into a crucial stage of sleep called deep sleep. Deep sleep is really important for your body and mind to recover properly. Athletes, on the other hand, might be better at managing their body temperature, so late exercise might not affect their sleep in the same way.

By comparing very active people (endurance athletes) with people who don't exercise regularly, the researchers hope to understand if exercising late in the day affects deep sleep differently for these groups. They'll be measuring things like how long it takes to fall asleep, the quality of deep sleep, and changes in body temperature to get a clear picture.

Key takeaways

This study explores how exercise timing affects sleep.
It compares morning vs. late afternoon exercise.
Researchers are looking at both active athletes and inactive individuals.
The focus is on deep sleep and body temperature.
The age range for participants is 18-30 years old.

Who may be eligible?

To join this study, you need to be an adult between 18 and 30 years old, male or female. There are two main groups we're looking for.

One group is for people who are very active, like endurance athletes. This means you do a lot of aerobic exercise (like running or cycling) – more than 5 hours a week for at least six months – and you compete at a regional level. The other group is for people who don't exercise regularly and tend to sit a lot, meaning you don't meet the recommended amount of weekly physical activity.

However, there are also some reasons why you couldn't join. For instance, if you've been told you have a sleep problem (like insomnia or severe sleep apnea), a mental health condition that needs treatment, or a serious health issue affecting your kidneys, breathing, heart, or muscles. Also, you can't take part if you are pregnant or breastfeeding.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 30 years old?
Do you either exercise a lot (like an endurance athlete) OR exercise very little/are inactive?
Do you NOT have a diagnosed sleep disorder (like insomnia or severe sleep apnea)?
Are you NOT pregnant or breastfeeding?
Do you NOT have a diagnosed mental health condition or serious kidney, lung, heart, or muscle disease?

Answer every question to see your result.

What does participation involve?

The detailed information for this study is not yet available, so we don't have information about visits, assessments, medication, or the total duration.

Potential risks and benefits

Since the detailed plan isn't available, specific risks and benefits are unknown. Generally, potential benefits in research include helping advance scientific understanding and potentially improving future health practices. Risks could involve discomfort from measurements or the time commitment. You always have the right to leave the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Chu Saint-Etienne
Verified postcode
Saint-Etienne, France· Recruiting

Common questions

What is 'deep sleep'?

Deep sleep is a very important stage of sleep where your body and mind do a lot of repair work and recovery.

Why might exercise timing matter for sleep?

Exercising can raise your body temperature, and for some people, exercising closer to bedtime might make it harder for their body to cool down and get ready for sleep.

Who can take part in this study?

Adults aged 18-30, either very active endurance athletes or people who don't exercise regularly, can participate, provided they meet other health criteria.

What will researchers measure?

They will measure things like how long it takes you to fall asleep, the quality of your deep sleep, and your body temperature.

Will I have to take any new medicines?

The information provided does not mention any new medications being given as part of this study.

How to find out more

Frédéric ROCHE, PhD

frederic.roche@univ-st-etienne.fr 0477828695 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.