Have you ever launched into a workout feeling slightly down or maybe a little “stressed out?” But by the end of the workout, your mind had cleared and your mood has lifted. That’s the magic of exercise! Research shows regular physical activity benefits brain function in more than one way. Not only can it spur the growth of new nerve cells in part of the brain involved in memory, a process called neurogenesis, it also boosts mood. Yes, the “feel good” effect of exercise is real, and it’s one reason people keep doing it. Beyond the known health benefits, exercising regularly helps you maintain a healthy state of mind and better deal with stress.
We know that longer-term exercise has physical and mental health benefits. But what about a single, vigorous bout of exercise, a high-intensity interval training session? What impact does it have on mood? According to some research, 30 minutes of high-intensity exercise rivals anti-depressant medications for lifting the mood of people suffering from depression. It’s not clear why intense exercise boosts mood, but a theory is that the endorphin release you get from a kick-butt workout has beneficial effects on the brain and on mood.
What’s so special about endorphins? They’re natural chemicals your brain produces that have a pain-relieving, calming effect. Your brain makes more endorphins when you’re in pain or are under stress, as during challenging exercise. Fortunately, it’s a good kind of stress! The purpose of endorphin release is to mask the discomfort and ease the pain of working your body to the max. In fact, these chemicals are similar to opioid medications people take for severe pain. They also bring about feelings of calm, peace, and pleasure. So, it’s not hard to see why exercise is a mood booster. It’s also not difficult to see why more health care professionals are prescribing exercise for stress management and for dealing with anxiety and depression.
With regard to interval training and depression, an article in American Family Physician:
“Adequate trials on the role interval training plays in depression are lacking, but there are indications that the physiological changes brought about by high-intensity interval exercise are greater and longer lasting compared with changes from aerobic or resistance training.” So, high-intensity interval training may be the ticket to a better mood.
The endorphin release and mood boost that comes with vigorous exercise seems to lift the spirits of people who are down and those who are clinically depressed, based on preliminary studies. But the impact on anxiety is less clear. In one study, 20 male soccer players took part in a high-intensity interval training workout. The session lasted a total of 28 minutes and consisted of 4 minutes of active work followed by 3 minutes of recovery for a total of 28 minutes. Beforehand, the subjects responded to a questionnaire called the Profile of Mood State or POMS. This questionnaire is designed to measure mood state, how angry, tense, down, or tired you feel. The test was repeated afterward.
Surprisingly, the players scored higher for anxiety and fatigue after the high-intensity interval session. They also reported a reduction in “vigor,” or energy. The fatigue and a decrease in vigor was probably due to fatigue, but the increased anxiety score is more interesting. Can high-intensity interval training increase anxiety in some people?
Why might high-intensity exercise increase anxiety rather than reduce it? Intense workouts activate the sympathetic or fight-or-flight nervous system. In response, your body pumps out more hormone-like chemicals like adrenalin that prepare your body to fight or run by raising blood pressure and heart rate and by increasing alertness. Even after an intense workout is over, these chemicals remain in the bloodstream for a while. Since they’re activating, an intense workout session might temporarily make a person feel anxious if that person is prone toward anxiety. How an exercise session affects anxiety levels may depend on the balance between endorphins and fight-or-flight hormones. In some people, the endorphin effect may be stronger and intense exercise calms them. In others, the adrenalin effect may win out and they feel more hyped up and anxious. We’re all a little different, even in how we respond to exercise.
Another way exercise may quell anxious thoughts, independent of the brain chemical effects, is by distracting the mind from worries and obsessive thoughts. A vigorous workout can help break a cycle of negative thoughts and restore tranquility. Plus, regular physical activity of any type builds confidence because you’re mastering new skills and moving your body in new ways. Introducing variety into a workout also keeps motivation high and the challenge alive.
All in all, it’s less clear whether longer term, high-intensity interval training reduces anxiety. All in all, the evidence that high-intense interval training alleviates depressive symptoms is stronger than the evidence that it reduces anxiety.
If high-intensity workout can potentially boost anxiety in some people, it’s important to moderate it. Stick to a few 2 or 3 sessions per week. Pushing the body too hard can increase the release of stress hormones that fuel anxiety. Balance high-intensity workouts with ones that help your body recover, like yoga. Sometimes it’s tempting to push too hard, but, ultimately, it’s about balance.
High-intensity exercise is good for your waistline but it’s also good for your brain. If you’re feeling down or have had bouts of depression, there’s growing evidence that high-intensity interval training may help. The evidence is less clear for anxiety. But at the very least, it’s a good way to distract yourself from worries and do something good for your body at the same time.
· Science & Sports. Volume 33, Issue 4, September 2018, Pages e151-e157.
· VeryWellMind.com. “Exercise and Improving Your Mood”
· J Exp Psychol Learn Mem Cogn. 2014 Jul;40(4):1142-52. doi: 10.1037/a0036577. Epub 2014 Apr 21.