It’s common knowledge that exercise makes us feel better — everyone knows about those famous ‘endorphins’. While the full extent to which exercise impacts our brain and our emotional states are not yet fully understood, the current body of research indicates that how, and how often, we move are far more intimately related to our mood, productivity, creativity, and mental health than most of us realise.

In fact, if we look at the research, there’s a really good argument to be made that we should all learn to expand our appreciation of exercise from the usual ‘physical stuff’, to include variables like emotional regulation, mental wellbeing, and our ability to fully experience the joys of life. Across this article, we’ll flesh out why this isn’t hyperbole. Let’s deepen our ‘why’.

We’re going to first explore how exercise helps us become measurably better at dealing with stress. Then, we’ll cover the deep impact that regular exercise has on anxiety and depression. To bring it home, we then explore how the right types of exercise can objectively help us be the best versions of ourselves, put our best foot forward, and create a life experience with the most purpose, meaning and satisfaction. Let’s dive in.

Increasing your resilience through difficult times

“It is worth remembering that the time of greatest gain in terms of wisdom and inner strength is often that of greatest difficulty.” — The Dalai Lama

If this pandemic has taught us anything, it’s that the strength of our resolve — our overall resilience against hardship — is an important trait that we should all learn to nourish.

Stress is cumulative, and your body basically has the same physiological response to stressors, whether you’re desperately trying to find food for your starving family, or racing against an impending deadline at work. As stressors pile up, stress can become chronic. When stress exceeds our ability to cope, we hit a point called allostatic overload, which, as the phrase implies, is a burden that is more than we can handle.

In this overloaded state, your body has a hard time shutting off the stress response, resulting in chronic systemic inflammation, where your body can’t figure out how to down-regulate the inflammatory response. Allostatic overload has been associated with everything from increased risk of cardiovascular disease, gastrointestinal issues and diabetes, to depressive and anxiety related disorders.

In a landmark study of 872 people across a 20-year period, which you can read about here and here, the link between inflammation, chronic diseases and emotional reactivity to stressors was established. Higher levels of chronic systemic inflammation in the body have been linked to a weakened ability to deal with stressful events (and an increase in depressive and anxiety symptoms). Thankfully, they also found that regular exercise and quality sleep were at the top of the list of factors that helped lower chronic inflammation.

Chronic stress and inflammation have been linked to all kinds of unwanted things, like intestinal and gut issues, lactose intolerance, increased susceptibility to upper respiratory infections, increased cardiovascular disease risk, and even asthma. To make matters worse, a follow up study found that those with a poor ability to handle stress, if coupled with a chronic disease later in life, had about double the mortality risk of people who were able to manage stress well.

The good news? Your resilience against stress is trainable.

Through regular exercise, your body and brain can adapt to become more resilient, effectively shifting the goalposts of what allostatic overload is for you. Multiple studies have shown that through exercise, we can upgrade our ability to endure the hard times.

Regular physical activity moderates how our hormonal and nervous systems respond to stress, so we are less emotionally, physiologically and metabolically reactive. We also gain a more positive mood, increase neuroplasticity, and improve cognitive function, which are all critical aspects to solving problems and getting through the difficult periods in our lives.

Remember the chronic systemic inflammation and associated negative health consequences mentioned above? Exercise helps ameliorate that, too. In fact, regular exercise is one of the most effective tools available to mitigate chronic disease risk, improve stress tolerance, and reduce inflammation!

While it’s important to note that being consistent with exercise provides the most benefit, even a single 30-minute dose of moderate-intensity exercise has been shown to have significant stress-buffering effects. If you’re a regular exerciser, it’s even better news. Five months of regular exercise can significantly lower emotional reactivity to stressful events, and it has been suggested that exercising two or more times per week, for 20 to 60 minutes each time, for more than four weeks, can significantly buffer the negative effects of stress in the long term.

Key takeaway: consistent exercise helps us be stronger, calmer, and more reliable people, physically, mentally and emotionally.

Anxiety

When we’re anxious, we tend to have a disproportionately large reaction to a stressor. It has been reported that up to a third of us are affected by an anxiety disorder at some point in life, a term that includes panic disorder, social anxiety disorder, and generalised anxiety disorder, amongst others.

Over and over again, exercise has been shown to be an effective way to manage anxiety.

There appears to be a link between higher intensity exercise and its effectiveness for generalised anxiety disorder, as well as panic disorder. Interestingly, while the exact reasons why High Intensity Interval Training (HIIT) seems to be most effective for managing anxiety are not yet fully understood, it has been suggested that during more intense exercise, a person has to experience physiological effects that are similar to those experienced in a panic episode, like elevated heart rate and shortness of breath.

This may make high intensity exercise an effective form of exposure therapy, where those symptoms also become associated with a manageable, positive, productive activity, effectively desensitising the anxious or panic response.

When it comes to the best dose, research suggests that roughly 20 minutes of HIIT (at between 77% to 95% max intensity), done every other day, can lead to as much as a 40% drop in panic attack frequency in as little as 12 days. Other research suggests that HIIT is twice as effective as lower intensity exercise for helping with anxiety symptoms, as well as fast-acting, with results within just a couple of weeks.

Even though HIIT might be the best exercise solution, it should be noted that all forms of exercise can be beneficial for managing anxiety. One study found that just 30 minutes of moderate intensity exercise helped reduce the occurrence of panic attacks by half, compared to a group that received quiet rest instead.

Regardless of the intensity, the most crucial component is regularity: we need consistency to have lasting effects. If you’re suffering, it’s also important to know that the people who seem to benefit the most are those with the highest levels of anxiety.

Resistance exercises (like deadlifts, lunges and pull-ups) have also been shown to improve anxiety symptoms, with positive effects reported from just a single bout of strength training. Researchers have made a general recommendation of loading up on resistance around two to five times per week for several weeks, with the key component of long term success being regularity of training. Gives a whole new meaning to lifting stuff up off the ground, and pressing stuff overhead, doesn’t it? Lift heavy things to lift yourself up.

Exercise has been shown to be so effective that it’s been recommended as a treatment option for anxiety disorders, and in the best case scenario, used in tandem with traditional interventions like medication and cognitive behavioural therapy.

Key takeaway: If you’re experiencing anxiety, get a workout in. High intensity and strength training will likely help the most, but more important than getting it ‘perfect’ is that you just do something, and then try and do something again tomorrow.

Depression

The hypothalamic-pituitary-adrenal (HPA) axis (don’t worry, you don’t need to memorise this) is the system that controls how we react to stress, and it regulates all kinds of processes, from immune and digestive system function to our mood and emotions.

When stress becomes chronic, our HPA axis goes into overdrive, and has trouble chilling out, meaning all kinds of bodily processes start to suffer — we fall sick easier, and it becomes easier to spiral into negative emotional states. Yup, it’s that allostatic overload thing again. Unfortunately, this state is associated with a greater risk of developing depressive disorders.

Fortunately, what some researchers call ‘chronic exercise’ (read: consistency!), is an extremely potent tool to buffer our HPA axis response. Chronic stress makes things go into overdrive, resulting in an overwhelmed system and emotional state, while chronic exercise moderates our stress response, and helps us build tolerance. One grinds us down, one builds us back up.

In addition to helping our HPA axis chill out, regular exercise increases something called brain-derived neurotrophic factor (BDNF — again, no need to memorise). BDNF levels drop with chronic stress, and increasing our BDNF through exercise is associated with decreases in depressive symptoms; we become better at dealing with stressors. Another win for exercise.

Chronic psychological stress can also cause a significant immune response that isn’t caused by pathogens, leading to something called sterile inflammation. While the pathways aren’t fully understood yet, this chronic inflammation (that we discussed earlier in the resilience section) is associated with depression.

So, what types of exercise work for mitigating depression risk or depressive symptoms? The good news is, basically all types of exercise work, even for those with resistance to drug treatments, but regularity matters, so it’s important we find things we can stick to in the long term. Some types of exercise do seem to work better than others, so let’s dig in.

A study of over 33,000 people over 11 years found that with just one hour of exercise per week (of any intensity, including leisurely walking), 12% of future cases of depression could have been prevented. Additional research suggests that three exercise sessions per week, for more than 12 weeks, yields us a larger reduction in depressive symptoms, indicating that consistency really does matter.

Resistance training, as well as aerobic exercise, have also been shown to improve depressive symptoms, with evidence suggesting we should do some combination of them all, and exercise roughly three times per week for greater benefits. In a fantastic recent review on the effects of exercise on depression, it was suggested that while both aerobic endurance exercise and strength training are good options for the treatment of depression and depressive symptoms, strength training seems to be a little bit more effective.

A relatively low dose of HIIT (a 14-minute session, twice per week, for 12 weeks) has been shown to significantly reduce inflammation, which reduces depression, with the action of muscle contraction playing a significant role in the benefits. Other research indicates that increasing intensity appears to have greater antidepressant effects, with high intensity exercise yielding the greatest impact (note: high intensity was indicated at around 80% of max intensity and above, so going absolutely ‘all out’ isn’t necessary).

Maintaining a lower visceral fat level is a great way to keep chronic inflammation lower, and both HIIT and resistance training have been shown to work well to do this, so we should probably do both. However, it should be noted that researchers are still in the process of discovering what is most effective, and there is a limited amount of research that suggests that while HIIT is effective at reducing depressive symptoms, we might want to keep it a little below maximal intensities (perhaps around 80% to 90% intensity will do) when we’re super stressed out, as the stimulus itself can be acutely stressful.

In addition, other restorative exercise modalities like yoga, qi gong and meditation also show promise in improving mental health, and specifically, depression, although further research is needed to understand ideal frequencies and styles.

Key takeaway: There’s a link between chronic stress, inflammation and depression. To ameliorate depressive symptoms, get some movement in. If you can, lift some weights or get a quick HIIT workout in, to help address all these issues.

Optimising your experience of life

Simply doing more physical activity is associated with a greater sense of purpose in life, as well as an increased sense of meaning in life. In a study of over 10,000 participants, it was shown that happier people live more active lives, and that we’re at our happiest when we move more.

In fact, it was found that simply increasing sedentary time by half an hour per day for two weeks resulted in significantly increased mood disturbances (including anxiety, tension, fatigue and anger), and higher levels of stress-related inflammation in the body. In another study, reducing an active person’s step count to less than 5000 steps in a day for just one week resulted in a 31.2% drop in life satisfaction (thankfully, life satisfaction returned once activity resumed).

Evolutionary biologists suggest that we evolved to be rewarded for physical activity, because hunting and gathering were essential to our survival and perpetuation as a species. This means that whether we like to admit it or not, we’re hardwired to feel our best when we move a lot, because we get bathed with neurochemicals that make us feel good in anticipation of exercise, during exercise, and after exercise.

Why is this important? Well, to feel our best in life, and to get the most satisfaction out of life, we need to leverage these neurochemicals that our biology rewards us with. We don’t need to hunt and gather anymore, but we can use exercise as a tool to optimise our mood, function, performance, and experience of life.

Exercise has been shown over and over again to increase both dopamine (which helps regulate motivation, pleasure from achievement, and the desire to repeat the activity) and serotonin (which helps stabilise our emotions and mood, regulate sleep and appetite, as well as increase feelings of happiness, cooperation and focus). An increase in these two crucial neurochemicals is strongly associated with lower levels of depression and anxiety, and higher levels of satisfaction and happiness in life.

In fact, the more we exercise, the more we activate and sensitise our brain’s reward system, which means we get to enjoy more of those good, satisfying feelings than people who don’t exercise. We actually seem to increase our ability to enjoy regular life experiences more than those who don’t exercise, and we become better at the act of overcoming obstacles. That’s insane. That’s real evidence of positive knock-on effects to all aspects of life.

It was traditionally thought that endorphins were the cause of the exercise-induced euphoria, commonly known as the ‘runner’s high’. While it is true that exercise increases endorphin production, this neurochemical actually acts more to modulate pain so we can keep going (which is obviously important as well!). It seems that another neurochemical, endocannabinoids, is likely responsible for the euphoria we get from exercise, and the increase in endocannabinoids that we can get from exercise is also associated with reduced anxiety and depressive symptoms, as well as improved mood, memory, focus and optimism.

Interestingly, it seems that we need the full spectrum of exercise to optimise the mix of all these neurochemicals, from slow activities like walking, to moderate activities like cycling and running, as well as vigorous activities like HIIT. That being said, it is important to remember from earlier in this article that doing something is always better than nothing, because any type of exercise works to benefit our mental health.

The link between consistent exercise and improved mental health, along with the data that show regular exercise is associated with lower risk of dementia, improved learning, cognition, memory and focus, increased productivity and creativity, and better sleep quality, make a really, really, really compelling case to evolve our reasons “why” we work out.

Putting it all together

“Anything that keeps you moving and increases your heart rate is enough to trigger nature’s reward for not giving up.” — Kelly McGonigal, PhD, from her book, The Joy Of Movement

Okay, so if we put all this information together, what types of exercise should we do to cover all our bases?

When it comes to the specific types of exercise that are most beneficial for resilience against stress, ameliorating anxiety and depressive symptoms, and maximising our experience of satisfaction, happiness, contentment and sense of purpose, it’s still not yet crystal clear what works best, but we do have some very strong hints that can help us craft a narrative.

For the 7th time in this article, I will mention again that the most critical factor that is discussed over and over again in the literature is that consistency matters, with the sweet spot being around three times per week of any sort of exercise, across any intensity range. Find any type of exercise you can stick to in the long term, and do those activities often.

Beyond that, we’ve got four broad categories to think about, with research to back them up:

1. Easy to moderate activities like walking, cycling and jogging

• Walking has been shown to be significantly beneficial for improving mood and mental health, and if you pick up the pace to a brisk walk, it may be even more beneficial.
• Somewhere around 10,000 steps is a good target to aim for, but it should be noted that simply participating in some walking and doing it regularly yields a greater effect than hitting that target.
• If you’re short on time, consider interval walking, where you brisk-walk for two to four minutes, then walk at a slower pace for an equal amount of time, for about 30 minutes. (As an interesting aside, if you have a lot of time, walking 100km or more, over days and weeks at a go, has also been found to be good for our mental health).
• If you pick the pace up to a jog or faster cycle, and take it to 20 minutes and beyond, you can get a greater release of neurochemicals that get you that ‘runner’s high’ feeling.
• You’ll likely get even more benefit if you do it outside in nature, and extra points if you do it with a buddy or group sometimes.
• Side note: If you’re interested in exploring the other wide-ranging benefits of walking and ‘easy exercise’, check out our deep-dive here.
  

2. Vigorous exercise, like HIIT

• HIIT has been shown many times over to be effective for improving mental health, with recent evidence demonstrating how HIIT was more effective than moderate intensity exercise in helping with anxiety, depression and stress across COVID lockdown periods (although it should be noted that moderate intensity exercise was still effective).
• While increasing intensity has been shown to have greater antidepressant effects, ‘high intensity’ doesn’t mean you have to try to destroy yourself, with a range of around 80% to 90% of maximal intensity being the sweet spot.
• The size of the HIIT dose doesn’t need to be overdone, either, with effectiveness shown with just a 14-minute session, twice per week, with the sweet spot probably being around 20 minutes, every other day.
• HIIT seems to act faster than other types of exercise to help us feel less anxious. Even with panic disorder, just 12 days of doing a 20-min HIIT session every other day has been shown to get a 40% drop in panic attack symptoms. But, it should be noted that consistency in the long term matters more than anything if we want to have better mental health in the long term.

3. Strength training (also known in the research as resistance training)

• Resistance training, with exercises like squats, deadlifts and rows, has been shown to be beneficial for reducing anxiety and depressive symptoms, and improving overall mood.
• A whole range of exercise session durations, from short to long, have been shown to be effective, with a study of 1,877 participants indicating that you can get antidepressant effects even at low volumes. This suggests that you’ll get benefits even if you just challenge your muscles a little bit a couple of times per week.
• You can get a significant reduction in anxiety from just one session of resistance training, but a range of around two to five times per week will likely provide us with more benefit.
• Interestingly, slightly lower loads with a slightly higher rep range seem to work a little bit better than really high loads at a lower rep range, and the overall Rate of Perceived Exertion (RPE) only needs to be around 14 out of 20, with a post-exercise muscle soreness rating of around 4 out of 10, indicating that while we need to challenge the muscles, we don’t need crazy all-out maximal efforts to get our mental health benefits.

4. Activities that promote mindfulness

• Practices like yoga, meditation, tai chi and qi gong have promising evidence emerging that indicate their effectiveness for improving anxiety and depressive symptoms, as well as mood, especially if done consistently for around eight weeks or more, and roughly around three times a week, although much clarification is still needed as there are many styles and techniques for all these practices, and across a wide range of durations.
• Interestingly, there is a little bit of research that suggests taking a mindful approach to any and all of the exercise we do may increase our ability to stay consistent with it, and to keep stress levels around it lower, although we do need more research to clarify here.

“This unpredictable journey we call life is best taken one step at a time. Each step you take moves you toward better health. Better physical health. Better mental health. They really are one and the same.” — Jennifer Heisz, PhD, from her book, Move The Body, Heal The Mind

Looking good naked and improving your push-up numbers are great reasons to exercise. At the right time, they can provide the motivation we need to keep going. This lengthy article is an attempt to help us all deepen our reasons ‘why’, beyond the surface-level stuff.

Perhaps more important than how we look, or what other people think of our bodies, is how we feel about ourselves. What if these additional benefits, like fortifying your ability to get through challenging times, your ability to battle anxiety, depression and negative emotions, and your ability to greatly improve your overall experience of life, end up being way more important than how many pull-ups you can do? What if you can make that leap right now?

We can use exercise as a tool to influence our biological systems, so our lives feel more purposeful, meaningful and fulfilling overall. To a pretty great extent, we have significant control over our mood, relationships and outlook on life. This means if we take control, and exercise some personal responsibility, we can approach life in a more positive and optimistic way.

We can become better at rising to challenges, as well as tackling those challenges with greater grit, confidence, emotional stability, and cognitive abilities. Taken together, can these things help you form a greater inner narrative of “why I exercise” than “to lose some fat and look hot”?

That’s up to you now.