My PT teachers professes working-out/training in early morning hours is the best time to do so. A quick search on benefits of morning walk (or similar phrases) reveals a lot of information which seem to be backed by sound scientific evidence. In fact it is common wisdom around the world, across all cultures.
Okay - accepted. But why is it beneficial in first place? Because there is plenty of oxygen in the morning; or is it?
After long hours of darkness (plants respirating at night) when first light comes plants would have just started photosynthesis, that too at a pretty slower rate (owing to lower intensity of light at dawn). In fact I remember having read something about compensation point
The (light) compensation point is the amount of light intensity on the light curve where the rate of photosynthesis exactly matches the rate of respiration. At this point, the uptake of CO2 through photosynthetic pathways is exactly matched to the respiratory release of carbon dioxide, and the uptake of O2 by respiration is exactly matched to the photosynthetic release of oxygen. SRC
So now, obviously, we can establish the fact that concentration of oxygen should be/is much lower than carbon-dioxide in early morning hours.
- So why morning walk or early morning exercises?
- If oxygen content is important why not exercise in early evening hours because not all people would like an endurance drill at theoretically perfect time of noon :)?
- Is there some other mechanism makes oxygen content more than carbon-dioxide content in the morning?
Personally - I do feel more fresh in the morning hours but maybe that is because of my internal biology, correct me if I am wrong.
P.S. I am not a biology student, so pardon my ignorance.