This Wall Street Journal Article, "The Peak Time For Everything", makes a ton of sense for me. For instance, I've become more of a morning person of late and can see how I've been trending when it comes to work productivity and making the most of my days in general. (Not sure how much longer being a morning person will last, seeing how, ironically, I'm beginning to write this just before midnight, bucking a long running trend.)
Deeper into the article, it mentions that muscle strength tends to peak between 2pm and 6pm and hand eye coordination is best during the late afternoon. As I am now so ready to shed my winter racquetball schedule and begin to look towards summer, I'm entering my annual "need a break" time. Here in the Northeast, winter racquetball means regular weekly meets "inside". This past winter I was grouped up very early on Saturdays and some semi-regular weekday evenings, which is typical for me. So after 6 months of "regular" inside play, I always feel like I need time to get away. Especially from playing so regularly, at "regular" times. None of which were between 2pm and 6pm this season.
Besides just the resting up, it's also a time for transition. Starting up during the spring means breaking the usual time of play, and beginning the "play it by ear" phase of deciding when to get on the park lists. Which means, I can play anyday of the week. Once the summer season hits full swing, the times tend to trend more towards early afternoons. When I add to that, what I take away from the article, I can sense as I type this out, the difference. I can see how things are just more energized during the summer. It's not like I show up to play with no energy during the winter months, but socially, it's a different vibe outdoors, especially summer afternoons. It just "feels" like a different energy level. We also play into the evenings, though the part about the lower risk of injuries mentioned in the article may be a stretch, because by that time, we've already been playing for quite a few hours.
You players who know what I'm talking about may also notice a difference in energy levels during the summer, that's if you're like me and typically break out of your winter "inside" rhythm. You West Coast "mostly outdoor" guys may not relate to this transition. Then again, you guys are in your own little world anyway, over there. (Yea... I just said that.)
If you're reading this and you're an "indoor only" player, you're missing what you could be feeling.