Researchers at the Institute of Human Movement Sciences and Sport at ETH Zurich have found an interesting fact about exercise and sleep.
According to Science Daily, the researchers went through twenty-three studies that met their requirements on the subject and found that exercising four hours before going to bed doesn't affect a person's sleep. In fact, it actually improves sleep slightly as those who partook in the study and played some sport in the evening were in a deep sleep for 21.2 percent of their sleeping time. This was compared to 19.9 percent for those who hadn't done a sport at night. The deep sleep is something that's quite important as it allows the body to recover physically.
Now, this doesn't mean you should do an intense exercise routine an hour before your bedtime. In this case, it's been said that it took people longer to fall asleep after they did their intense workout. This was due to their bodies not entirely recovering from the activity. However, as the Deputy Head of the Exercise Physiology Lab at ETH Zurich, Dr. Christina Spengler noted: "As a rule of thumb, vigorous training is defined as training in which a person is unable to talk." What this means is that the average person isn't going to pull this off, but should probably pay some attention to what they're doing during the exercise, to avoid it. You can consult the helpful chart below to determine which exercises (and at what intensity) may be harmful.
You see, a person needs cooldown time or they won't have the best sleep that they possibly can, if their heart is still racing when they want to sleep, it's going to cause them to possibly stay awake longer than if they were relaxed.
Despite that, this all kind of makes sense when you take the time to think about it. Some exercise might kill off that extra energy that people have before they go to bed. So, doing a quick jog could lead to someone being just tired enough to fall asleep instead of staying awake watching videos all night.
All in all, this will boil down to how you operate best. If you are someone who might want to work out at night, then exercising during the evening isn't a bad thing, you would just have to adjust this new information into your sleep schedule.