Negative Effects of Too Much Daily Intense Exercise

I just got over something like this. I had been going every single day cranked to 11. Thing is, I knew I was probably overdoing it, but I felt great. Until I didn’t. Just had no energy for a day and a half. Hopped on my bike yesterday and shook it off.

The apple link didn't work for me
searched for a direct link: https://www.theladders.com/career-advice/if-you-exercise-more-than-this-amount-of-time-per-day-the-results-are-disastrous


This makes me wonder how it relates to serious athletes. When young and in my prime, I recall exercising up to 4 hrs a day and swimming 7 miles a day in total distance.

Arnold Schwarzenegger said, when asked how much time one needs to spend in a gym, 'if you are there more than an hour you are doing it wrong'.
I am not sure in what context he said it though, he probably meant at any one time because as a pro he was training three times a day. I think there is such a thing as overtraining especially while doing a HIIT training. A relatively slow cardio like a road bike ride can easily last more than that but high intensity interval probably should be kept under an hour.

charmmeth wrote: »

This seems to be researching the effects of continuous high intensity exercise, and I think it is pretty clear that this is not great for the body. Also, I was left wth some questions about how active their test group was outwith this particular form of exercise?

I quite often do an hour or more of exercise in the morning, especially if I have a long day of meetings (=sitting at my desk) coming up. I mix forms of HIIT with rowing (often ome form of pyramid, so varied intensity) and stretching. This quite often puts me over the 152 minutes of exercise in total for a week, but I suspect it does not put me over 90 minutes of high intensty, given the varying intensity of what I do. This is anecdotal, but over a period of months, I certainly don't feel that I have had any of the negative effects described here. So my question would be: what form of exercise was the sample group doing?

Did you read the linked article at TheScientist? There's much more detail in that about the type of exercise (stationary bike) and how it was structured (type of intervals and whatnot).

https://www.the-scientist.com/news-opinion/extreme-exercise-carries-metabolic-consequences-study-68581

There's also a little more info there about the elite athletes part of the research, and its implications.

The actual research writeup in Cell Metabolism seems to be paywalled, but the summary (with select graphics) is available here, along with the details needed to access the article if you have a institutional access some way, or are willing to pay:

https://www.sciencedirect.com/science/article/abs/pii/S1550413121001029?via=ihub

FWIW, this is just personal opinion, but the other content I linked above makes the study sound less dippy. Reading the first-linked post, I was thinking "no one outside the calorie-obsessed blogosphere is structuring their whole exercise life as entirely *true* high intensity, all the time, are they?". I admit, extreme high intensity is exhilarating (I've done max-effort intervals in the larger context of a training program, and max effort in races, up to measured HRmax) . . . but it's clearly fatiguing way, way disproportionate to fitness or calorie benefits.

Coaches I know don't structure high-level successful programs that way, it's inconsistent with what I learned in coaching education, etc. Even here on MFP (and in my real life, based on friends/acquaintances), the serious recreational athletes are using some kind of structured, varied-intensity program to improve fitness and performance (sometimes a pretty detailed, complicated periodized program), not just going max hard every time.

So, the initial article made the study seem more like a debunking of things that well-informed coaches/athletes wouldn't do in the first place, which was kind of surprising to me, coming from serious academics. With the additional details, though, it looks like the study's focus was at least partly on *why* "all high intensity all the time" may not be a great idea, alongside looking for where the approximate "overdoing" line might be in relatively untrained people.

It seems like another situation where there's a gee-whiz blogosphere pop-practice view (that pulls little bits of science out of context and runs with them beyond all rationality); and a more serious, disciplined realm where a more well-rounded view of the science is put in practice . . . kind of like the gee-whiz side of diet/nutrition ("No white foods!" "protein shakes and green smoothies for all!" "IF and low carb is universally essential for weight loss because evil insulinz!"), vs. the better-rounded science, which is more complicated, and leads to more nuanced, complicated practice.

Call me cynical, I guess.

Bugs me when studies like that call 4 or 8 min intervals HIIT.
Compared to intensity level in 30-90 sec intervals.

That's just good old SIT (Short IT) - which still points out the potential negatives when overdone.

So whether an athlete that could do longer sets of intervals, or more intense - there's usually a reason why their coaches don't have them.

That protocol though, and on a road bike, totally fits in with another study from years ago about recreational cyclist that do lots of group rides, little specific training.
While they do improve in fitness and ability, it's usually much slower than coach led ones trying to enter the pro-field with young ones that still have a job-life.
It came down to basically the same thing - every group ride was pretty intense, very interval in nature at high level for pretty long periods of time. Very slow improvement compared to focused training, that many times wasn't even the same volume of intensity.
So this study is very interesting as to why it's likely happening.