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Body clock and exercise

body clock and exercise
Many people wonder about when it’s the best time to have a workout. In this body clock and exercise article I will attempt to answer that very question.

About your body clock

The body has an internal biological clock, that runs more or less on a 24 hour cycle known as the circadian rhythm. Your brain regulates at what time it is best for certain activities in our lives, from telling us what time to get up, when to eat, be more physical and when to sleep. The body has several different controlling cells within the brain for each individual process. They produce hormones and control the central nervous system. Much of our internal clock is regulated by light and darkness and by what time of the day you get up on, on a regular basis.

For most people, the morning starts slow and gradually you wake up, with great vigour and focus usually by mid morning, however this is often followed by an early afternoon dip in energy and then again followed by an increase in physical ability from late afternoon to early evening.

Oddly enough, although most of us tend to sleep once in a 24 hour cycle at night, our body is naturally set up to have an afternoon nap at that time when you feel that early afternoon energy dip. The very reason that some countries have an afternoon siesta.

Exercise and your body clock

As you can see from above there is potential for times of the day where you may get an advantage in working out at a particular time. There is however some disagreement from experts for the best time. Some will say late morning 11am-12am, others will say 2pm-7pm.

Most research however has shown that your strength is said to be best between 2pm and 7pm. Late afternoon/early evening workouts seem to improve athletic performance. This has also been proven in that many athletic records are made with athletes competing in the late afternoon/early evening. While the worst time for physical performance was found to be in the early morning. The reason late afternoon or early evening was found to increase physical performance was due to a number of factors, such as your body temperature is slightly elevated at this time and therefore your muscles work more efficiently and you may even be less prone to injury. There was also an advantage for those looking to build muscle when training at this time of day, due to the fact that the catabolic hormone cortisol is lowest at this time. With the late afternoon shown to have the lowest cortisol level to testosterone level balance of the day and is therefore the most anabolic time of the day to train.

If you plan on working out late into the evening however (2-3 hours before bedtime) be aware that for some people it may keep you awake, while others will get a good night’s sleep. This is something you will have to work out for yourself and monitor your sleep patterns if you do workout quite late.

For those on a weight loss plan, cardio may be best done in the morning due to the potential fat burning advantage of working out on an otherwise empty stomach and that may be a priority over performance.

For those that must workout in the morning it isn’t all bad news and while you may not get a performance boost, working out in the morning can help get you up and running and raring to go for the rest of the day. You can get a metabolic boost, which can translate into more body fat being burned throughout the day. I would however always suggest having a protein drink 30 minutes before working out in the morning to help retain muscle or slowdown muscle breakdown.

Other factors

Your body clock may differ than other people, so be aware that if you get up earlier, your afternoon time may be earlier than a person who gets up later. In other words each person’s body clock is set by the time that they do certain activities, not just by the actual time in the day and that your body can adjust/reset its body clock as necessary.

Other factors that may alter your body clock include, your age, as it has been found that younger trainers up to the age of around thirty may do well in the very late afternoon or early evening, while apparently those over 40 may be better training earlier. Having said that, I for one seem to have better workouts in the late afternoon or early evening and I’m 49 coming on 50 this year!


Even though it has been shown that the late afternoon does seem to give you a slight performance advantage, you cannot get away from the fact that the time you have your workout must fit into your schedule and around work or family, so don’t worry too much about it. Also as stated you can actually teach your brain/body when to be ready to train, by having a regular consistent time for training and this suits many people who do great simply working out when they want to, have to or are in the mood for it.

Finally I have found regardless of any science/research on when it is best to train, is to train when you are ready for your workout. On hot sticky summer days, I have always found it best to workout in the very late afternoon/early evening. Simply work out when it best suits you not what science says.