A lot of people don’t really think about what time of the day they should do exercise, however science tells us that there are optimal training times when you can achieve maximum impact. If you plan your training around your circadian rhythms, you’ll become faster, stronger, and even more powerful. You’ll also be able to gain more muscle, become more flexible, sleep better, and reduce the risk of injury.
What Is The Science Behind Optimal Workout Times?
A study carried out by Küüsmaa et al. examined whether training programs were more effective when carried out between 6.30am and 10am, or between 4.30pm and 8pm over a period of 24 weeks. Although endurance and strength performance improved in a similar way across both groups, men who trained during the evening gained more muscle.
The Importance Of Circadian Rhythms
Our circadian rhythms are the daily cycles of our biological activities. The body has its own internal clock which regulates when every system should be activated. When it comes to athletes, the daily variation in energy metabolism, hormonal milieu, and core body temperature are the key factors that circadian rhythm influences.
As an example, a high testosterone level benefits strength development and muscle growth. Therefore, it makes sense to train more during the hours when testosterone levels are higher than cortisol levels. Production of testosterone is higher during the night and lower in the daytime.
Meanwhile, cortisol production is lower during the night, rising rapidly after awakening then decreasing gradually during the day. When it comes to core body temperatures, it’s important to note that the higher the core body temperature, the better our joint mobility, nerve conduction velocity, muscle blood flow, and glucose metabolism.
The majority of people achieve a higher muscle activation level during the evening, with people typically being strongest at the time that their core body temperature achieves its peak, which occurs during the evening.
When Should I Work Out?
When we take a look at circadian rhythms of hormones, core body temperatures, and gene expression, the most effective time for scheduling resistance training is between 2.30pm and 8.30pm as long as your sleep-wake cycle is regular (i.e. between midnight and 8am). If you have a sleep-wake cycle that is irregular, for example because you work shifts, you should wait a minimum of six hours after you wake up before you train.
Nevertheless, it’s important to pay attention to your own biorhythms. It’s always wise to train at times when you feel you are performing at your personal best. If you want to experiment with your optimal performance time, using your heartrate as your guidelines is the best course of action. Core body temperature and resting heart rate have a strong correlation, so the time when you reach the peak of your resting heart rate typically represents the best time for training.
Unfortunately, though, not everybody has enough time to do a workout at the time that is physiologically optimal for them. In such cases, there are a couple of options that allow you to train either at night or during the morning without causing too much damage to your training.
First, you can consume caffeine which will effectively force your body to enter daytime mode. While this may offer as few benefits, there are some drawbacks to this approach. Firstly, caffeine decreases your T/C ratio and won’t elevate your morning growth hormone level to your afternoon level. Also, you can develop tolerance to the ergogenic effects of caffeine if you consume over 50mg-100mg each day. Furthermore, consuming caffeine during the evening may disrupt your sleep.
Secondly, you can choose a specific time to train then maintain consistency. Eventually, your body is going to adapt and change its circadian rhythms, reducing the decrements to your performance at that time. Although it won’t entirely offset the differences between training in the evening and training in the morning, it will help you body to acclimatise by boosting your performance-related circadian variations during the day.
If you maintain meticulous control of your circadian rhythms by using light therapy and supplementation as well as consistent training and nutrition, you’ll find that you can make significant shifts in your optimal training times and eventually achieve results that are comparable with training during the evening even when you train during the morning hours.
Are There Exceptions To This Rule?
There are always exceptions to rules, and if you’re doing an especially stressful job, you’ll find that you may produce better results if you train at lunchtime rather than after finishing work. Long commuting, physical stress, and high levels of responsibility cause mental stress while physical stress like manual labour also take their toll on your body.
This results in fatigue after work that can offset all of the benefits that you could achieve from your optimal physical state during the evening. There is a study that shows people who work shifts experience their peak level of performance before going to work, followed by during their lunchtime, with after work being their lowest performance level. Therefore, scheduling training during lunch or before work is best for shift workers.
Does It Really Matter When I Train?
Most people don’t spend a lot of time thinking about the optimal time for training, and even fewer take the time to schedule their sessions at the hours when they’re biologically primed to achieve maximum performance.
Although it can make a difference to your fitness achievements if you work out at the optimal time of day for you, it’s important to recognise that it’s more important to train in the first place than to perfectly time your training sessions. If you have a schedule that stops you from doing your workout at the ideal time during the evening, doing your workout at a time that suits you should be your top priority. It’s better to take the right amount of exercise than to struggle to plan your workouts at just the ideal time.