In today’s all-out, all-the-time fitness climate, going hard and fast is valued – if not outright demanded – by many gym-goers who think they haven’t done anything of value unless they end a session panting in a pool of their own sweat. And instructors are all too happy to oblige, whether it’s in high-intensity boot camps modeled on popular TV shows (you know who you are, celebrity trainers), soul-destroying cycling studios or purportedly “hardcore” weight lifting-focused sessions that resemble the typical heavy-metal concert mosh pit. There seems to be more than enough supply and demand for this trend to continue as if life isn’t hectic enough.
But maybe it shouldn’t. When redlining at maximum effort becomes a daily thing, an athlete of any fitness level can start to run into some serious problems (pun intended). First, it takes the central nervous system up to 72 hours to recover from an all-out effort. So hammering yourself again 12 to 24 hours after your last vision-blurring sprint-fest is completely counterproductive if you value any sort of opportunity to adequately repair. Another branch of the neural system – the autonomic nervous system – can also be adversely affected by repeated max-level efforts not interspersed with adequate R and R. If you think of the continual balancing act between the sympathetic (fight/flight/freeze) and parasympathetic states as a see-saw, doing only high-intensity training over and over again is like a World’s Strongest Man competitor bouncing on one end while my little eight-year-old son is catapulted up into the air at the other. Should this balance be swayed too much in favor of the sympathetic nervous system, the body stays on high alert. This can disrupt sleep, chronically elevate stress hormones like cortisol and trigger inflammation that can, if left unaddressed, cultivate disease.