Why do I have insomnia after strength training?

The core reason is that high-intensity strength training disrupts the circadian rhythm of the autonomic nervous system, causing nerve excitability, hormone levels, and core body temperature that are supposed to be reduced at night to be stuck in a high state. When you lie in bed, you will naturally toss and turn and cannot fall asleep.

When I was training for a 120kg PR in the bench press two years ago, it was almost 8 o'clock when I got off work and rushed to the gym. I held my breath and went up to the bar in less than a minute between sets. After training, I drank two cups of ice protein powder and walked home. I felt hot all over in the November evening breeze when I shaved my face. , lying in bed, my mind was still replaying the feeling of exertion from the last set. I could count the plaster lines on the ceiling after tossing and turning until after two o'clock. The next day, I deadlifted to 80kg and my waist collapsed. After that, I never dared to touch heavy weights two hours before going to bed.

But not all nighttime strength training will cause people to suffer from insomnia. I have a veteran who has been training for five years. He does shoulder and back training from 9 to 10 p.m., and the weight is not low. After training, he will snore after five minutes when he goes home and touches the pillow. I have read in sports medicine literature before that as long as the training is strong, The heart rate should be controlled below 70% of the maximum heart rate, and the end time should be at least 1.5 hours away from sleep. For people who have maintained regular training for a long time, it will basically not interfere with sleep. Most people who are prone to insomnia are those who suddenly increase the amount, push the maximum weight, or have a nervous constitution.

Think about it, strength training, especially heavy-weight compound movements such as squats, deadlifts, and bench presses, are originally supported by sympathetic nerve excitement. When reaching the limit, adrenaline and cortisol will surge upwards, and the core body temperature will be 0.5 to 1 degree higher than usual. These two indicators are originally high during the day and slowly decline at night. If you fill them up before going to bed, you are like a bus driver who is about to get off work and is dragged onto the highway by you. Where can you stop? There are also many people who are used to injecting nitrogen pumps and icing on the ice before and after training. People with slow metabolism can have a half-life of caffeine of 6 hours, which is equivalent to if you drink it after training at 10 o'clock, half of the caffeine is still in the body at 4 o'clock in the morning. It is strange that you can fall asleep.

There are also many fitness coaches who hold different opinions. They believe that insomnia after training is more of a psychological problem. For example, being too excited after just unlocking a new weight, or not doing the movements correctly during training, lying on the bed tossing and turning over the details of the movements, has little to do with physiological factors. I personally tried it once. After practicing, I didn’t touch my phone or think about the training content. I went home and lay in bed and listened to white noise for half an hour. Although I still fell asleep more than ten minutes slower than usual, it was not to the extent that I kept my eyes open until the middle of the night. It seemed to make sense.

If you really only have time to practice at night, you might as well move the heavy compound movements to the first half of the training, and then leave some time for light weight exercises and static stretching. Don't drink stimulant drinks after training, and take a shower with warm water of about 40 degrees, which can not only relax the muscles but also help lower the core body temperature. After I adjusted the training rhythm, even if I started training after 7 o'clock in the evening, I rarely had insomnia anymore.