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How Long Does it Take For Exercise to Help Depression?

Written by Dr. Ruscio on October 12, 2023

Written by Dr. Ruscio on October 12, 2023 — Reviewed by Aimee Gallo

Dr. Michael Ruscio is a DC, Naturopathic Practitioner, researcher, and clinician. He serves as an Adjunct Professor at the University of Bridgeport and has published numerous papers in scientific journals as well as the book Healthy Gut, Healthy You. He also founded the Ruscio Institute of Functional Health, where he helps patients with a wide range of GI conditions and serves as the Head of Research.

Unpacking a Landmark Review About Exercise and Depression and the Best Way to Exercise for Depression

• How Long Does it Take for Exercise to Help Depression|
• How Exercise Improves Your Mood|
• Your Exercise Treatment Plan|

We’ve all struggled with our mood from time to time. I know I have. One out of every 20 American adults experiences depression regularly, which seems like a public health concern we should all be aware of [1]. But what you may not be aware of is how a consistent exercise program could help. Whether dealing with situational anxiety, depression, or more chronic mental disorders, exercise seems to be a reliable salve for just about everyone.

Let’s back up because that is a really big statement. I don’t mean to suggest that those with major depressive disorder or severe anxiety can simply exercise it away or that you should fire your therapist and go off your antidepressants because you joined a gym. However, there’s reason to believe that exercise will almost certainly help move the needle toward relief. If you’ve ever experienced the endorphin rush of a runner’s high, you probably already believe me, but the mechanisms I’m referring to go far deeper and last longer than a temporary rush of endorphins.

A recent umbrella review looking at 97 meta-analyses of 1039 unique randomized controlled trials with over 128,119 individuals determined that all forms of exercise are not only beneficial for depression and anxiety, but are as good as or better than prescription medication and/or psychotherapy [2]. This is a huge deal!

In science, we always hesitate to say that something is conclusive, but this incredibly comprehensive review is just about as close as it gets. It’s safe to say that regular exercise can improve your overall sense of mood and well-being, and that we have a tremendous amount of scientific research to back up that claim.

But how long does it take for exercise to help depression? How exactly does it work? How much exercise do you have to do? How hard do you need to work to feel the effects? Is any particular style better than anything else? How long do the mental health benefits of exercise last?

I’ll answer all of these questions below, but I’ll start by letting you know you don’t need to join a CrossFit gym to make this happen, but you do need to stay consistent. Let’s dig in.

Types of Exercise that Help Depression

Every type of exercise studied seemed to ease depression and anxiety. The types studied included [2]: 

• Aerobic exercise
  • Brisk walking
  • Biking
  • Biking
  • Interval training (could be moderate-intensity or high-intensity, or a mix of both)
  • Swimming
  • Jogging/Running
  • Dancing
• Strength training
  • Body-weight
  • Weight lifting
  • Resistance bands
  • Gym machines
• Mixed-mode (aerobic + strength training)
• Mind-body (Yoga, Tai Chi, Qi Gong, Dance, Stretching)

Interestingly, strength training seemed to have the biggest impact on depression and depressive symptoms, while mind-body work had the biggest impact on anxiety [2]. I recommend doing a mix across all the categories, not just because it might cover all the bases, but because there are so many beneficial side effects of diversifying your exercise routine.

Even if aerobic exercise isn’t at the top of the list for anxiety or depression, it improves your cardiovascular health and is a great way to get your heart rate into that optimal range. Both strength training and aerobic exercise help maintain fast-twitch muscle fibers, muscle mass, and bone density, which is especially important as we age.

It’s also a good idea to get out into nature. Connecting with nature is an incredible way to ground yourself (literally put your bare feet on the ground), breathe fresh air, and experience the great outdoors. It does wonders for stress reduction and mental health improvement.

How Long Does it Take for Exercise to Help Depression?

The answer to this question varies from person to person, but the landmark umbrella review I mentioned above found that at about the 3-month mark, the positive mental health effects of exercise seem to flatten out. It’s possible (and likely) that this effect is because of the already-improved mood of the participants, and after 3 months, their exercise routines were more about maintenance than improvement [2]. 

While a group of studies often isn’t a direct prescriptive, this review is incredibly comprehensive, so it’s likely safe to bet that you’ll experience maximum mood improvement around the 3-month mark and you’ll need to maintain your exercise program long-term for sustained benefit.

When healthy adults stopped doing regular aerobic exercise, they started to have depressive symptoms within 3 days to two weeks, especially if they were female. Surprisingly, the increase in depressive symptoms was not accompanied by higher levels of inflammatory markers or lower levels of brain-derived neurotrophic factor (BDNF) [3], meaning that other exercise-induced mechanisms are at play when keeping depression under control. More on BDNF and inflammation in the next section.

The Ideal Exercise Routine for Helping Depression

Research consistently shows that 4–5 days per week of moderate to high-intensity exercise for 30–60 minutes at a time is the sweet spot for maximum mental health and physical health benefits. I can’t stress enough (and this is from personal experience) that going all-out at high intensity is not the goal. 

It comes back to the Goldilocks principle of hormetic stress—you want enough stress and intensity to create positive effects but not work yourself so hard that you wreck your body and eventually burn out. More isn’t better across any of the categories: frequency (days per week), intensity, or duration.

If you’re curious whether you’re experiencing burnout or would like to learn more about what it looks like, my conversation with Mike T. Nelson is really relevant here. He specifically points out that over 60 minutes of exercise becomes destructive and counterproductive when it comes to stress hormones.

How Exercise Improves Your Mood

So what’s happening in your brain and body that improves your mood after engaging in physical activity? There’s still work to be done to figure out exactly how exercise improves depression and mental health conditions like anxiety and depression. Determining the how is a lot more complex a challenge than observing the consistent effect across a huge swath of subjects. That being said, we do have some good hypotheses about how it all works.

Theoretically, exercise could improve depression by [1, 4]:

• Increasing the expression of brain-derived neurotrophic factor (BDNF)
• Increasing available serotonin and norepinephrine
• Reducing systemic inflammation
• Regulating the HPA axis 

Higher BDNF is thought to improve depression by promoting cell growth and creating new blood vessels, thereby changing the makeup of certain brain regions [5].

Brain-Derived Neurotrophic Factor (BDNF) and the Effects of Exercise

Brain-derived neurotrophic factor (BDNF) is a neurotransmitter modulator that plays an important role in the survival and growth of neurons (brain cells). It’s also a key component to neuronal plasticity, which is essential for learning and memory and has a positive impact on the release of serotonin and dopamine into the bloodstream.

Most (but not all) recent evidence supports the theories around how exercise impacts BDNF and symptoms of depression. One meta-analysis found that acute exercise improved BDNF levels in healthy people of all ages [6]. A single study looking at long-term aerobic exercise (up to 12 weeks) found that it raised BDNF levels across all participants, especially women, older adults (over 60), and those who are overweight or obese [6]. Another recent meta-analysis discovered that habitual, regular exercise increased BDNF in people with major depressive disorder (MDD) (7).

In contrast, two systematic reviews (which provide a lower strength of evidence than the ones above) found that physical activity had NO effect on BDNF levels in exercisers with major depression or healthy people who stopped exercising and became depressed afterward [3, 8]. Even though the exact relationship between exercise, BDNF, and depression is unclear, exercise is still beneficial for physical and mental health, and, therefore, worth doing.

Furthermore, our muscles act as an endocrine organ, which activates during exercise. Physical activity causes muscle tissue to release a myokine (an anti-inflammatory compound) called irisin, which leads to the release of BDNF [9]. Sauna also has a favorable impact on BDNF and inflammation and can positively impact anxiety and depression. 

Stress: Exercise and the HPA Axis

Surprisingly, one factor linking exercise to improved mood is stress. We’ve been conditioned to demonize stress as a killer, but actually, some stress is a necessary part of life, both physical and emotional—in the right (manageable) quantities. Chronic stress is dangerous, but acute (temporary) stress can actually be beneficial.

Hormetic stress, or a state of hormesis, refers to that perfect “goldilocks” state of just enough stress to keep things running as they should, but not so much that it’s crippling or traumatic. Without acute stressors to overcome, our minds and bodies become less resilient and prone to both psychological and physical injury over time.

So what does that have to do with exercise? Exercise is physically taxing and stressful on your body. The acute stress of exercise temporarily increases cortisol production during exercise. This targets and temporary release of cortisol trains the hypothalamus (which regulates cortisol levels) to keep the body at a lower resting level of cortisol [4]. Similarly, exercise increases blood pressure in the moment but leads to lower overall blood pressure.

This cortisol effect doesn’t seem to happen the same way in patients with major depressive disorder, especially those on antidepressants. However, the HPA axis is engaged in a different way, suggesting that exercise still has a lot of benefit for those with this type of mental illness. A 2016 systematic review found that repeated bouts of exercise reduced a different stress marker (copeptin), which also affects the HPA axis, possibly normalizing it and creating a positive effect on mood via a different pathway [8].

Your Exercise Treatment Plan

Getting started is the most important part of any exercise plan. Building a habit takes time and can be a challenge, but slow and steady wins the race. If it’s helpful to set a goal for that three-month mark so that you can look back at how you felt when you started, do it, but break it down one week at a time so you don’t get overwhelmed.

If you’re not an experienced exerciser, start by increasing your activity level from zero to something low- to moderate-intensity. This could be a brisk walk for as short as 10 minutes to start. Ideally, you’ll break a sweat. After a week or so, tack five more minutes onto your walk and start doing body-weight squats. Maybe start with two sets of 10.

Habituation and consistency are key. There are tons of exercise apps out there that can help keep you consistent and accountable, and having a workout buddy is always a plus too. Apps are also great for mind-body work, which is the best place to start if your challenge is more about anxiety than depression. Waking Up is a great meditation app that also includes discussions of various techniques and thinkers in this space.

If you can afford it, you might consider working with a trainer if you’re new to strength work so that you can avoid injury.If you’re fine-tuning as an experienced aerobic exerciser, it’s likely time to add in some strength training in order to maximize the benefits for your body and your mind. Strength training has the biggest on depression, and it’s an important component of physical fitness, especially as we age.

Consistency Is Key When It Comes to the Antidepressant Effects of Exercise

Most people will experience a positive effect on their mood within 3 months of starting a new exercise routine. And you will likely need to stick with it, as symptoms can return within a week after stopping. The perfect routine is more about finding a workout that you can be consistent with, not necessarily the number of reps you do.

Take a look at the types of exercise I’ve listed—aerobic, strength, and mind-body, and choose something from one of those lists that speaks to you, one you will consistently do. And it’s okay to switch it up—it might even be ideal, especially if you’re not quite sure which ones you’ll like best. Some people do better if they can start in their living room. Some people need the accountability of a gym membership or a workout partner. Some (like me) know that the only exercise they’ll do will have to be outside in fresh air. 

The bottom line is that we know that exercise can improve your mood, even if the science on exactly why and how isn’t conclusive yet. 

We would love to help you get started on the best exercise plan for you. Reach out to our clinic to talk to one of our trained staff members and book your appointment.

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