The physical effects and benefits of strength training and cardiovascular activity are well-known and documented. A conversation with people who are consistent in an exercise program reveal how good they feel INSIDE in addition to improved body image. The rush or "high" they feel after a satisfying bout of exertion is commonly mentioned. The question then becomes: what does this "high" do on a brain level?
Yes, it releases endorphins, etc. But why does it feel so good long-term?
1) Combats Stress
Research has shown that the good ole minimum of 20 minutes a day, 3 days per week is sufficient to diminish overall perceived stress. Let's obviously not settle for that but it is a good start. The reason behind this effect is that stress contributes to depleting dopamine and serotonin stores through the effect of cortisol, the stress hormone. During and after exercise, the brain centers for reward and memory get flooded and ride on increased release of dopamine and serotonin, which has an inverse relationship with cortisol therefore decreasing the constant feeling of stress.
2) Increases Focus
Physical activity is, well, physical! It forces us to move our body. Movement is processed in the brain specifically at the structure called the cerebellum which has strong neural connections to the higher-order processing prefrontal cortex. The more the prefrontal cortex is being stimulated, the higher its ability to focus on complex and high-demand tasks. Those effects lasting about 2 hours post-workout, it is then a good use of your time to exercise before studying for a big test at school or before an important meeting at work to take advantage of this boost.
3) Improves Memory and Learning
Along the lines of increasing focus and attention, physical activity boosts the performance of the hippocampus, the memory center of the brain. The levels of brain-derived neurotrophic factor (BDNF) released after a few months of consistent 60-75% of maximal heart rate stimulates the activity of hippocampal cells and the rate at which they sustain connections within the cell network as well as the amount of new connections. Long-term learning and recollection of concepts and both old and new memories are then positively affected. It makes you wonder why more and more schools are cutting recess...
4) Lowers Cognitive Decline and Dementia
More of a long-term effect than a more instantaneous "endorphin release" kind of effect. More and more research is showing a decrease in as much as 50% in the risk of Alzheimer's and dementia conditions in adults that start regularly exercising as late as in their sixties. 60 years old! There could be even more benefits in starting at en even earlier age but more research is still required.
5) Stranger No Danger: Socializing is Good for You!
Going to the gym, you are bound to meet strangers. The added accountability provided by your new workout buddies combines with the increases in dopamine and serotonin released when you exercise as a group to boost motivation and perseverance up. This in turn translates to improved cardiovascular and muscular gains. No one can complain about that!