Exercise for Anxiety and Depression
By Igor Klibanov
You’re a personal trainer, and you work with clients who have mental health issues (be it anxiety, depression, or something else). You know they’ve gotten better over time, thanks to exercise, but what’s the best form of exercise for different mental health issues, and how does it work? That’s what we’ll talk about in this article.
Exercise Prescription for Mental Health
Interestingly, when a doctor prescribes a medication to his/her patients, s/he says the name of the medication, the dosage, whether it should be taken with meals, or away from them, and whether it should be taken in the morning or evening. There is precision in the prescription. But when a doctor tells his/her patients to exercise, s/he leaves it at that. No more information.
So what is the patient to do? Should they do cardio or strength training? How frequently? At what intensity? For how long?
The truth is that just as the doctor has the right medication for each condition, so should exercise recommendations differ based on the specific condition. Fortunately, in recent decades, there has been more and more research on the right type and “dosage” of exercise necessary to improve and support different conditions.
Anxiety is a persistent worry and restlessness, which is normal to most people. By the time it crosses the line (once the label of “anxiety” is official), the person is in a pretty dark place. Fortunately, exercise can help with that (as you already guessed).
In one study, researchers took 26 well-conditioned college athletes and divided them into two groups. The first group cycled for 30 minutes at 70-80% of their maximal heart rate. The second group lifted weights for 30 minutes at 70-80% of the 1RM. The group that cycled had a lower anxiety level after exercise, compared to before. What about the group that lifted weights? Their anxiety levels were actually higher after exercise than before. But, when they were measured through the State-Trait Anxiety Inventory (STAI) questionnaire at 20 and 60 minutes post-exercise, their anxiety levels only returned to their pre-exercise levels.
The conclusion: cardio is more effective than strength training for anxiety reduction, when done at 70-80% of the maximal intensity.
What about duration? What’s the least that you need to exercise to have anxiety-reducing effects? Most studies start at 20 minutes, but that’s because they don’t directly look at the minimum effective “dose”. There are currently two studies available that look at the least amount of exercise someone needs to do to have anxiety-reducing effects.
Their conclusion: somewhere in the 10-15 minute range. That’s pretty cool! For only 10-15 minutes of exercise, anxiety is reduced, and usually for up to 6 hours.
But there are still a few unanswered questions, like:
- Does it only change their anxiety in the moment, or does it change how they are as a person?
- What about people with severe anxiety? Does exercise work for them as well?
We now know that exercise works well for anxiety, and that cardio is more effective than strength training. How about depression?
In the case of depression, it seems that both cardio and strength training have equal effects. In one study, the researchers enrolled 40 women with depression and divided them into three groups. The first group was the control group. They didn’t exercise. The second group ran four times per week for 30 minutes, and the third group lifted weights four times per week for 30 minutes
The results: both the cardio and the strength training groups reduced their depression symptoms by an average of 50%. Not bad, considering that exercise was used as a stand-alone therapy (no medications or psychotherapy were used).
But just as in anxiety, there are a few unanswered questions, such as:
- How does exercise compare to medications in those with depression?
- How long do the effects of exercise last?
- How does exercise affect those with severe depression?
Mechanisms: How does it Work?
There are eight hypotheses that explain why exercise works to improve mental health. Three of those will be covered here.
- Hypothesis #1: Self-Efficacy
Self-efficacy means that you feel like you’re in control. When you have anxiety or depression, it feels like things are happening to you. You feel helpless, out of control. But then you start exercising, and you quickly realize that if you exercise you can make yourself feel better, which brings back a sense of control to your life. You start to understand that you can control how you feel. You can control when, where, and how intensely you exercise. Exercise doesn’t just “happen” to you. You make it happen.
- Hypothesis #2: The Tryptophan/Serotonin Hypothesis
It is believed that one of the mechanisms of fatigue in exercise is the increase in tryptophan levels in the brain. Tryptophan is an amino acid and it gets converted to serotonin. Serotonin is the “happy chemical.” When serotonin levels rise, you feel happy and relaxed.
- Hypothesis #3: Increased Alpha Waves in the Brain
If you were to hook up the brain to an EEG machine and measure electromagnetic waves, you’d notice four types of waves: alpha, beta, gamma and delta. The beta waves are what you experience when you’re awake and concentrating. The gamma and delta waves predominate in deep sleep. It’s the alpha waves that are less present in the person with anxiety. Alpha waves signal relaxation, and they’re most evident when a person is relaxing, daydreaming, or in that period when lying in bed and you’re not quite asleep, but not quite awake. Exercise helps increase alpha wave activity and calms you down.