A recent study on exercise and the prevention of depression aimed to determine whether or not exercise provides protection against new-onset depression, the intensity and amount of exercise required to gain protection, and how the protection might work.
To do this they examined 33,908 adults, selected on the basis of having no symptoms of common mental disorder or limiting physical health conditions. The researchers followed them for 11 years, during those years they collected measures of exercise, depression, anxiety, along with a range of potential confounding and mediating factors.
What they concluded was that regular exercise of any intensity does indeed provide protection against future depression. Even relatively modest changes in levels of exercise may have important public mental health benefits and prevent a surprisingly high number of new cases of depression.
The study suggests that 12% of future cases of depression could have been prevented if the participants had engaged in at least one hour of physical activity each week. Interestingly, the majority of the protective effects occurred at low levels of exertion and were observed regardless of intensity.
The HUNT Study
Another study (the HUNT study) followed thousands of participants in Norway for 9-13 years. They found their volunteers by inviting the entire population, aged 20 or older, to fill out a basic screening form for depression and anxiety. After reviewing the submissions, they invited the happiest 70% to participate. 8,400 were excluded due to serious physical illness, which left nearly 34,000 in the study.
Potentially confounding data, such as smoking status, BMI, resting heart rate, and demographic data were collected at various visits over the years. Blood pressure, heart rate, weight, height, waist, and hip circumference were measured by specially-trained nurses. The research team also accounted for variables which might impact the association between exercise and common mental illness. These included socio-economic and demographic factors, substance use, new onset physical illness, and perceived social support. In the end, about 22,500 participants completed the study.
At the beginning of the HUNT study, all participants were asked to report their frequency of weekly exercise and their degree of aerobic intensity using three different categories:
- Without becoming breathless or sweating
- Becoming breathless and sweating
- Exhausting themselves
During the follow-up stage of the study, participants completed a self-report questionnaire (using the Hospital Anxiety and Depression Scale) to indicate whether the subject was experiencing any anxiety or depression during the years of the study.
Correlation Between Exercise and Depression
In a nutshell, those participants who exercised were less likely to develop depression than those who didn’t. The cool thing is, it didn’t matter how much exercise they did as long as they did some kind of “deliberate physical activity” for a minimum of an hour per week.
Yup, only one hour of exercise for the entire week and it also did not matter how intense that exercise was. It could be a leisurely bike ride, CrossFit, spin class or yoga. We’ll get into some other creative options in a bit.
Research author Samuel Harvey from Black Dog Institute and UNSW stated: “We’ve known for some time that exercise has a role to play in treating symptoms of depression, but this is the first time we have been able to quantify the preventative potential of physical activity in terms of reducing future levels of depression. These findings are exciting because they show that even relatively small amounts of exercise—from one hour per week—can deliver significant protection against depression.”
That’s good news for all of us who just can’t or don’t want to commit to a daily and lengthy gym session or can’t even imagine signing up to run a marathon.
Staying on an Exercise Routine
The social and physical health benefits of exercise partially explain the shielding of depression, but the research also reported that some biological mechanisms, like alterations in the vagal tone, did not appear to have a role in protecting against depression.
If the social benefits of exercise make the real impact, it would appear that simply getting out and about, getting your heart rate up, and engaging in some active self-care is what makes the real difference. Although the researchers felt that a lot still remains unexplained.
There is also a question of whether there’s actually a “reverse causation” going on—people with mental health issues may struggle to get enough exercise in the first place. So it can be a chicken-and-egg scenario: which comes first, the lack of exercise or the depression?
The thought here is that if we are sick, or blue, or overwhelmed, it is our lunchtime workout or our morning jog that is the first thing to get taken off of the to-do list. But the data suggests that if we maintain even a brief schedule of light activity, we lower the chances of developing depression in the future. Preventing 12% of depression cases is significant, and you don’t even have to step foot in a gym to make it happen.
These results drive home the need to integrate exercise into mental health plans and into broader public health campaigns. If we can find ways to increase the population’s level of physical activity, even by a small amount, we will likely see substantial physical and mental health benefits across the board.
With sedentary lifestyles becoming the norm worldwide, and rates of depression being on the rise, these results are of particular importance because they highlight that, once again, even a small lifestyle change can lead to significant mental health benefits.
How to Exercise and Prevent Depression
Well first, 60 minutes per week works out to 8.5714 minutes per day. You could even round that up to 10 minutes per day, to make it easy and potentially give yourself one day per week where you get too busy, forget or otherwise miss your preventative workout. What can you do between 8-10 minutes per day?
Go for a walk: Let’s start with an easy one. The researchers pointed out several times that intensity was not a factor so why not just get up from your desk, your lazy boy, even out from behind your standing workstation and go for a 10- or 15-minute walk.
Tabata Set: A Tabata set involves alternating between a high-intensity and an anaerobic exercise for 20 seconds (hard), followed by 10 seconds (easy), for a total of four minutes. Heck, you could even do this one twice.
The Scientific 7-Minute Workout: The New York Times made this workout famous a few years ago. 12 bodyweight moves that require only a chair and a wall, reportedly combines cardio and weights into about seven minutes of discomfort.
The Get-Fit Guy’s 10-Minute Full Body Burn: With one pair of dumbbells and a chair, step, stairs, or box. Warm-up with 25-50 jumping jacks, then complete 10-12 repetitions of each set of exercises twice, back-to-back with minimal rest, and move on to the next set.
- Set 1: Dumbbell Squat With Overhead Press to Bent Side Raises
- Set 2: Dumbbell Push-Up Row to Single Arm Dumbbell Row
- Set 3: High Knee Step-Ups to Reverse Lunges
The Get-Fit Guy’s 10 Minute Maximum Calorie Burn: Complete this routine as a circuit, three times through, with minimal rest between exercises. No warm-up required.
In addition to mood, exercise helps improve a number of health problems, including high blood pressure, diabetes, and arthritis.
- 25-50 Jumping Jacks
- 5 Push-Ups
- 10 Squat-Thrust-Jumps
- 5 Push-Ups
- 10 Vertical Jumps
- 5 Push-Ups
Throw a ball or a frisbee around: Why not make it fun? Grab a friend or two and head for a park or a large parking lot and toss a baseball, football, or a frisbee around. I am willing to bet that not all of your throws will be exactly on target so aside from the throwing and catching, there will probably be some running and likely some shouting and laughing as well.
Rethink your commute: Is there a way you can avoid sitting in traffic, in a car, or on a bus, and get some exercise instead? I am sure there is. You can park further from the door, get off the bus a few stops early, ride your bike to work or walk. I am a huge believer in adopting a car-less mindset, even if you don’t want to sell your old clunker and become a pedal-estrian.
In the episode How to Do High-Intensity Interval Training, you learned that short, intense bursts of cardiovascular exercise can boost the metabolism and ultimately burn many more calories than long, slow cardio sessions. In the same way, quick 10-minute workouts spread throughout your day can elevate your heart rate, get you breathing hard, stimulate a toning effect on the muscles, and also protect you from future depression.
More Evidence on Exercise and Mood
We’ve talked about how studies show that low levels of the two neurotransmitters, glutamate and gamma-aminobutyric acid (GABA), often lead to depression. But according to a study in The Journal of Neuroscience, moderate exercise can increase these levels which can result in increased resilience and a capacity to respond to mental challenges.
According to the Mayo Clinic, exercise helps prevent and improve a number of health problems, including high blood pressure, diabetes, and arthritis. The ongoing research on depression and exercise shows that the psychological and physical benefits of exercise can also help improve mood.
Even though the links between depression and exercise aren’t entirely clear, it is clear that working out, pumping iron, hitting the bricks, pounding the pavement, and all other forms of getting active can definitely ease symptoms of depression, protect against future episodes of depression, and simply make you feel darn good.