While there is some evidence to suggest we might perform better later in the day, reasons for this are still unclear. Whether it is a result of body temperature, time awake, or daylight remains to be seen and there are a number of variables between individuals that need be controlled for researchers to discover a clearer answer. It might seem like something sporting bodies should take into consideration, but the fact remains that when it comes to staging competition, there are a number of factors that go into the timing of an event. Consider Eliud Kipchoge’s attempt to break two hours in the marathon for Breaking2, a race that saw him lace up first thing in the morning. This wasn’t a mistake by event organisers, but something more practical. If he had raced later that evening, he would have had to consider evening temperatures and what to eat all day to fuel his performance. Sometimes, early morning starts are just easier.
According to a new review published in Medicine & Science in Sports & Exercise, timing can be quite a crucial component when it comes to peak performance. It’s long been thought that if you want to perform at your best - whether it be a workout, training or competition - you should opt for the late afternoon or early evening. Based on our circadian rhythm, it’s thought that this is the time when your body temperature is highest, allowing for looser muscles, faster metabolic reactions, and faster transmissions of nerve signals.
Of course, it’s not as simple as it sounds. If it were, Olympic events would solely run in the afternoon and early evening, and personal bests would be made with apparent ease. The fact remains that the key question that has long plagued researchers in the field of sports and exercise is whether our body clock peaks at a certain time, or whether peak performance is simply based around how long we’ve been awake for or when we last ate.
As Alex Hutchinson writes for Outside, “Several studies have shown that if you shift your sleep-wake cycle by a few hours, you also shift the timing of your peak performance by a few hours, suggesting that the external rhythms of daily life matter. Then there’s the matter of individual variation: it seems unlikely that early birds and night owls would be peaking at the same time.”
In light of this, Harvard researcher Raphael Knaier sought to gather as much data as possible on the subject and discovered a total of 63 relevant articles, but due to inconsistencies in testing, only 29 of the studies were used in the meta-analysis. These were then divided into four categories: jump height, anaerobic power, handgrip strength, and endurance exercise. The results found “strong evidence” that jump height and anaerobic power peak between 1pm and 7pm. “Some evidence” suggests handgrip strength peaks between 1pm and 9pm. When it comes to endurance, little difference was found between times.