Exercise is indisputably good for your physical health. It has been associated with lowered risk of mortality, CVD, diabetes and other conditions. But, does exercising confer similar benefits when it comes to your mental health? We read through the latest research and while the answer is a yes, there are some caveats worth knowing about.
“Mental health is more than the absence of mental disorders”. As defined by the WHO, mental health is a “state of well-being” in which you can make good on your abilities, deal with stress, work productively and contribute positively to your community. This is undoubtedly core to our ability to think, express and interact with one another. 
Your mental health level at any point in time is determined by the multitude of social, psychological, and biological factors surrounding you and your loved ones. Stressful work environments, gender discrimination, detrimental lifestyle choices and below-par physical health, have all been linked to poor mental health outcomes. This is notwithstanding the particular genetic, psychological and personality factors that allow some people to be more vulnerable to mental health problems than others.
Globally, one in five people experience a common mental disorder every year.  This ranges from Generalised Anxiety Disorder (GAD) and Depression to PTSD and even OCD amongst others. In order to truly enjoy life, we need to be able to protect our mental health as much as possible. Which brings us to the increasing body of evidence that associates physical activity with promise in managing depression, anxiety and PTSD. 
Various epidemiological studies have associated sedentary lifestyles with higher risk of poor mental health. A cross-sectional study conducted between 2011-2015 across 1.2 million individuals in the U.S. concluded that exercise was significantly linked to self-reported lower mental health burdens.  On similar lines, a study looking at the connections between aerobic and muscle-strengthening exercise and depressive symptom severity among 17,839 U.S. adults found that those engaging in both moderate-to-vigorous aerobic physical activity (walking, cycling, running) and strength/resistance training were least likely to report depressive symptoms. 
Exercise benefits mental health by lowering anxiety, depression, bleak moods, as well as boosting self-esteem and cognitive performance. . Other hypotheses that have been proposed to explain the beneficial effects of physical activity on mental health include self-efficacy and social interaction. While formal group initiatives can help people with extremely poor mental health, most can benefit from lifestyle changes that aggregate moderate-intensity movement throughout the day. Event brisk walking 3x a week is shown to be a good start. 
Furthermore, as per Dr. John Ratey in his blog for Harvard Health, exercising can help ease anxiety in a few ways. It helps distract you from your source of anxiety as movement decreases the tension in your muscles. Exercise spikes your heart rate, which in turn can modify your brain chemistry, to increase the availability of important anti-anxiety neurochemicals such as serotonin. Exercise also activates the frontal areas of the brain responsible for executive function, which helps control the amygdala, our reacting system to real or imagined threats to our survival. By engaging in regular exercise you can increase the neuroplasticity of your brain to build resources that bolster resilience and adaptive learning. 
Specific health benefits from regular exercise, including improved sleep, increased libido, improvement in mood, and stress relief need to be emphasized and reinforced by all of us until it becomes second nature.
First things first, you don’t need to spend hours slaving away at the gym, performing strenuous exercises, or running countless miles to see results. It is enough to engage in 30 minutes of moderate exercise 3-4 times a week. In certain situations, even a small amount of physical exercise is preferable than no physical activity at all, and listening to your body is crucial -- don't overdo it when you're tired.The goal is to commit to some modest physical activity on most days, and.gradually increase the duration as your habit develops. Moderate implies you're breathing somewhat faster than usual but not out of breath. You should, for example, be able to converse with your walking companion but not readily sing a song. That your body warms up while you walk, but not to the point of becoming overly hot or sweaty. The benefits of exercise will begin to pay off if you stick with it.
Despite the promising evidence from epidemiological studies, the use of exercise training as a mental health treatment remains limited. This is because of a few reasons. Firstly, there are large variations in how individuals respond to exercise treatment across different mental health conditions. In simpler terms, exercise can prove to be very effective in some people and not so effective in others. Studies suggest that greater age, cognitive impairment, and severity of depressive symptoms all contribute to the different degrees of benefits that exercise confers on mental health.  There still needs to be more research done on exactly whose mental health benefits from exercise and why.
Secondly, it is important to note that although exercise can have short term benefits for depression and anxiety, for any long-term results, one needs to continuously keep engaging in physical activity. The type of exercise can also make a difference, with aerobic exercise, particularly shown to reduce anxiety and sensitivity to anxiety.
In conclusion, exercising does have a significant positive impact on mental health, and could potentially be comparable to conventional psychotherapeutic and pharmacological approaches. However, the effects of exercise training vary across patient populations and training modalities, and to unlock long-term mental health benefits, you need to not drop off in the middle.