When is the Best Time To Exercise?

Good time to exercise

I was not a morning person when it comes to exercise/ training before I started work. I used to train mostly in the late afternoons. After starting work as a physiotherapist and seeing patients the whole day, it often left me too tired to train after work. It got worse when I had to help out with treating the athletes at national team trainings. These trainings often ended past 9 pm, leaving me with little time to train.

If you are a sports fan, you will know that NBA Finals, Champions League matches etc are all played in the late evenings. Almost all track and field world records are set in the evening as well. However, most road running world records, including Eliud Kipkoge's sub 2 hour marathon, are set in the morning.

It is not all physiological reasons though. Big track meets, NBA and Champion League Finals are at a venue, unlike mass participation endurance events which require early start times for road closures and avoiding hot weather. So when the human body is primed for maximal performance?

Evidence regarding circadian rhythms and physical performance suggest that we are at our best in the late afternoon or early evening. For most people, this is between 4-7 pm. 

A meta-analysis of 29 articles (63 were found but only results from 29 were suitable) were divided into four categories, jump height, anaerobic power (30 sec cycling sprint), hand grip strength and endurance exercise.  

Strong evidence showed that for jump height and anaerobic power the peak is between 1-7 pm while some evidence shows that hand grip strength peaks between 1-9 pm. 

However, most of the studies failed to find any significant difference for endurance exercise. Perhaps it may be difficult to look for subjects willing to run a series of 10 km runs (or longer) compared to hand gripping tests or jumps or bicycle testing.  Note that a higher core temperature may hinder rather than help endurance exercise.

During the late afternoons is when our core temperature is highest having risen from its lowest point when you get up in the morning. A warmer body means faster metabolic reactions, faster transmission of nerve signals and muscles that are warmed up and have more range. Definitely better for injury prevention.

If you shift your sleep-wake cycle by a few hours you can shift the timing of your peak performance by a few hours. The F1 drivers do this by remaining in their own timezone from Europe when they do the night race in Singapore.

However, there are advantages to exercising in the morning since you can typically control your mornings more than your evenings. All kinds of hurdles or excuses can pop up throughout the day that can prevent you from being consistent with your exercise. You may have to ferry your kids, get errands done or work late.  

Most endurance events like triathlons and marathons begin in the morning. If you want to train yourself to race under such conditions, training in the morning certainly helps. I used to wake up at 4.30 to attend swim training at 5.30 am by riding my bicycle there. Early morning race start times didn't bother me anymore after I got used to that.

Your circadian rhythm regulates blood pressure, body temperature, metabolism, alertness amongst other physiological functions. Tweaking your circadian rhythm can 'teach' your body to perform better at certain times. Just like when you need to adjust to a new waking time on your alarm clock, your body will get used to the change and you may even wake up before the alarm goes off after a while. 

Once you determine that a particular time of day works best for your schedule, body, event etc, you can start to train your body to match it. If you exercise in the morning, your body will learn to adjust to exercising at that time. You will get used to waking up, eating, drinking, using the toilet etc. After a while it becomes second nature.

Evidence may show that the best time of the day to exercise is the late afternoon to early evening. My take is exercise at whatever time suits you best as some exercise is better than no exercise, especially in Singapore when the weather is warm year round. Researchers in Guadeloupe failed to show any difference in the time of day for sprint cycling, squat and jump performance because it was always warm and humid there. And Guadeloupe's weather is just like Singapore.

References

Aoyama S and Shibata S (2020). Time of Day Dependent Physiological Responses To Meal And Exercise. Frontiers Nutr. DOI: 10.3389/fnut.2020.00018

Blonc S, Perrot S, Racinais S et al (2010). Effects Of 5 Weeks Training At The Same Time Of Day On The Diunal Variations Of Maximal Muscle Performance. J Strength Cond Res. 24(1): 23-29. DOI: 10.1519/JSC.0b013e3181b295d6

Knaier R, Qian J, Roth R et al (2022). Diurnal Variation In Maximum Endurance And Maaximum Strenhth Performance : A Systematic Review And Meta-Analysis. M Sci Sports Ex. 54(1): 169-180. DOI: 10.1249/MSS.0000000000002773