Muscles have circadian clocks that control exercise response
Humans may be able to respond better to exercise during the daytime, suggests new research. Oxygen and the internal clock "Do a dance together" in muscle cells to make energy, they say. The discovery provides insights that could lead to optimizing muscle function. Ref. Source 3l.
I can't argue with the daytime being best but the big problem is work during the daytime means you can only do it later at night. If you're really dedicated then you can do it before work but that would be early morning before then sun even came up!
Does time of day affect the body's response to exercise? New research confirms that the circadian clock is an important factor in how the body responds to physical exertion. Based on this work alone, it's too early to say when the best time is for you to go for a jog. But at least in the lab, exercise in the evening seems to be more productive, although human lifestyles are much more complicated. Source 5u.