It's no secret. Talk to any fitness expert, read any research study, and the conclusion is always the same: exercise is good for you. But you don't need studies to explain the increase of serotonin, dopamine, and norepinephrine. And you don't need medical authorities to illustrate improved levels of "brain-derived neurotrophic factor" (BDNF). If you want answers, if you want the truth, you just have to lace up your shoes and experience it for yourself. Exercise improves body and mind.
Go for a jog, take a spin class, give the dogs a walk. You'll feel it. Physical exercise increases motivation, happiness, and vitality. It counteracts against the effects of stress. And it provides a better sense of well-being. So if the benefits are so clear, why not take advantage?
I've talked about writer's block in the past – The Big Fat Lie – and it is just that: an excuse. Writing takes discipline. You need to do it everyday. Schedule it. And protect that time – it is your salvation. Exercising the body works the same way. The excuse not to do it is easy. So challenge yourself - taking the difficult road is almost always more rewarding. And if you've finished a feature screenplay, you know this.
It was Aristotle who said, "We are what we repeatedly do. Excellence, therefore, is not an act but a habit." And if you ask me, we should listen to the wise old Greek philosopher. If you want to be a writer, make it a habit. Make it routine. Exercise your mind. But don't stop there. If physical activity improves the mind, do it and be better for it.
Physical exercise has always been a consistent part of my life, and like my writing, I schedule it. And sure, my body feels better, but it's my writing that also improves. If I'm stuck with a plot point or a character motivation or a particularly difficult scene, sometimes a quick run in the park is all it takes to sort things out – to find my answers.
I understand that hitting the gym or pounding the pavement isn't for everybody, but everybody surely can find a physical activity they enjoy: gardening, hiking, or yoga. It might take some effort, but once you find the Zen-like activity of choice and you make it a part of your daily lifestyle, you will see improvement in all aspects of your life, writing included.