Sunlight controls every biological function within your body. It literally gives us life. See what happens when you put a tarp over a plant. It will die. We are no different. Below are 3 areas I see footballers sabotaging their short-term & long-term performance:
How & WHY
Light (or the lack thereof) is how your body knows what time of day it is, what time of year it is, where you are on the planet., etc. This controls what hormones & neurotransmitters are produced, sent, and received. These are the things that make you lean, athletic, and full of energy compared to injured, tired, and carrying a few extra pounds. It is no coincidence that most pros come from areas of the planet with stronger sunlight. Sunlight directly affects your mood and brings confidence & positive energy into your life.