The best time of day to run depends on many factors, and can vary from person to person. In general, it is difficult to find time to run between work, responsibilities, family, and friends. For this reason, many runners lace up either in the early morning to start their day, or in the later evening, as an end to it.
Running in the early morning can often feel a bit more difficult, because core body temperature and metabolism are lower at this time of day. It may also feel a bit harder to get going on your run, even after a generous warm-up (which is a must!) because the lungs and muscles are stiffer, and your energy is a bit depleted from fasting overnight.
However, many people enjoy running in the morning as a refreshing start to the day, and feel it is easier to fit a run into their schedules if they do it before work, or before the rest of the world wakes up.
Core temperature and metabolism peak in the late afternoon/early evening, which means that it may feel easier to get, and stay, on pace during your run. You have also had a chance to fuel and hydrate throughout the day, making it easier for your body to use that fuel to create energy.
However, people may find it difficult to exercise after a long or stressful day at work, and psychologically this can be a more difficult time to run.
If your targeted race is early in the morning, try and train with some runs starting around the same time. Use these runs to adjust to the physical demand at that time of day, and to perfect your fueling strategy and warm-up routine. If you are trying for a personal best in a training session, go out in the afternoon or evening when your core temperature and metabolism are revved up, and your water and food intake will help you perform better.
The good news is your body can adapt to when you habitually exercise, so that over time you will find the rhythm that works best for you. And remember, any time of day is a good time for a run!
Lauren Alix, PT, DPT, CSCS, is a doctor of physical therapy at Hospital for Special Surgery. She has run two marathons and numerous other road races, and enjoys helping runners become better at their sport through running analysis, training, and rehabilitation when needed. Lauren is passionate about injury prevention in athletes, and specializes in treating orthopedic injuries. She received her doctorate in physical therapy from Springfield College in Massachusetts.