You know instinctively that the best time to train is whenever you feel most energetic and can fit it into your schedule. Individual differences regarding the best time of day to train come from the fact that each person has slightly different chronobiology, or circadian rhythms. Research into the area reveals some noteworthy points:
- In performance that relies on the anaerobic system, such as strength training, studies suggest strength performance is significantly greater in the mid-afternoon and early evening. This effect is most pronounced in regards to power production—when needing to produce maximal force at a fast speed.
- For sprint training, competing or working out in the mid-afternoon and early evening tend to produce faster times. Greater strength and speed later in the day are likely due to the fact that your body temperature increases as the day progresses, leading to enhanced muscle function and flexibility.
- For fat loss, there’s evidence that trainees experience a greater afterburn (EPOC) if they work out in the evening around 6 pm. Higher EPOC means the body burns more calories during the recovery period.
- For endurance training, studies show time of day doesn’t matter much for performance, but of course individuals will have distinct experiences.
- Protein synthesis peaks in the late afternoon around 5 pm, indicating that completing a muscle damaging workout around this time may be best for muscle building and fast recovery.