What is The Best Time to Go Running?

running on the roadIf your schedule is flexible and you are looking to optimize your training routine by running at the times of day when you’ll get the most benefit, don’t miss this quick guide:

What is The Best Time to Go Running?

Morning, Afternoon, or Evening?

Did you know that the time of day you choose to go running could have a noticeable impact on your performance, speed, and efficiency? Contributing aspects that change throughout the day and may thusly influence how well you run include:

  1. Your body temperature
  2. Your natural circadian rhythm
  3. Weather
  4. Your diet

Body Temperature

While it’s an age-old notion that the average human adult body temperature hovers around 98.6 degrees Fahrenheit, the truth is that your body temperature fluctuates throughout the day. Research has shown that body temperature is at its lowest first thing in the morning and its highest in the afternoon which can influence your run-time decision.

When your core temperature is at its warmest, that means your muscle fibers themselves are going to be more pliable and ready to work. This could allow for greater joint mobilization when you hit the road or trail as well as make you less vulnerable to injury.

Morning time, however, is often when outside temperatures are lower and more comfortable for running, lessening your chances of overheating. Though your body temperature is lower in the morning, if you want to complete your run before school or work, a dynamic warmup can help wake your muscles up and gradually increase your core temperature.

Circadian Rhythm

You may have heard reference to your circadian rhythm, or body clock, in regards to optimizing your sleep routine, but did you know that other biological processes also follow a circadian rhythm? Findings from a 2004 study from the American College of Chest Physicians revealed that lung function followed its own circadian rhythm and seemed to influence when and how much energy was expended throughout the day.

After studying 4,835 patients across 5 years, researchers concluded that airway resistance was highest around noon and lowest in the afternoon between 4:00 and 5:00 p.m. Effectively, lung function is at its best in the afternoon indicating runners could experience enhanced training by timing their runs later in the day.


A 2012 study out of France published in PLoS ONE examined the effects of environmental factors on marathon performance and found that air temperature was a much more significant climatic factor than dew point, humidity, atmospheric pressure, and atmospheric pollutants. After looking at race data of over 1.79 million marathoners over a 10-year period and across 6 marathons (per year), researchers discovered that changes in air temperature directly correlated with changes in running performance of both female and male runners.

To clarify, when outside air temperature increased above optimum, not only did performance and running speed decrease but a higher percentage of runners were more likely to withdraw from the race altogether.


Marathon runners know that sourcing the vast amount of energy needed in endurance running all comes down to the fuel inside your body – carbohydrates (including glucose), fat, and proteins. Muscles specifically prefer breaking down glucose for energy and storing it as glycogen making carbohydrates the most important fuel source.

If you think about taking off for a long run in the morning after you wake up, know that you have effectively fasted for 8 to 10 hours prior to running. No recent consumption of carbohydrates could leave your body without the stores of energy it needs to safely and successfully complete a run. Eating a small glucose-rich snack beforehand, however, could give you the calorie burn you need to tackle an early morning run as well as improve your fat-burning metabolism by triggering your body to burn fat for energy when it runs out of carbs.

A run in the afternoon, on the other hand, will get an energy boost from a carb-rich lunch you had a few hours earlier. That midday fuel can leave you feeling more alert and improve your overall aerobic capacity.

The Mental Factor

It’s clear that there are benefits to certain times of day, both morning and afternoon, when it comes to achieving peak running performance based on weather, diet, temperature, and your own circadian rhythm. But what about the mental factor?

For many runners, an early morning run is simply less daunting than one that follows a long day in the office. Lots of marathoners find runs help them wake up and refresh in the morning too. Afternoon runners, on the other hand, may experience more of the physical benefits later day runs have to offer including increased running efficiency. If you have the option to choose when you run during the day, keep all these factors in mind and incorporate your own personal experience and goals.

By James Flemming

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