Exercise intensity is associated with cardiometabolic health

As an anecdote of one, I was doing moderate intensity endurance exercise for a couple years with only modest improvements in basic cardiovascular metrics that kind of flatlined over time.

As an experiment, I switched to high-intensity interval type training for a couple months, which required about half the time to do. All of my cardiovascular metrics immediately changed in a strongly positive way. When I did the old endurance training, performance was much higher than it had been before the high-intensity training.

It is the strongest positive effect I have ever seen from any exercise/gym theory that has been widely promulgated. I never expected to see my cardiovascular metrics change as quickly or as much as they did.

I like sprinting a couple times up our hill, ca 10s each, 4-6 times. It’s full out, and when I‘m untrained (like now), I‘m quite exhausted afterwards.

But the dopamine boost I get from this is immense. It lasts 24-48h. I‘m in a general good mood for this period. Sometimes, a little more competitive than normal - that’s a downside.

Normal jogging or long walks don’t have this effect, at all.

I found that setting a two minute timer and running up and down a stair case with high intensity once per day can resolve a whole host of seemingly unrelated issues.

At first I thought they found something new, however it is known that exercise intensity should be of various types for the best health outcome. In my training regimen I already have a weekly session of high-intensity training, and other session at a lower intensity.

TL;DR: for some biomarkers, "sprint-interval exercise" (SIE) bursts as short as 5 min can be as effective as much longer periods of "moderate-intensity exercise" (MIE).

Specifically: MIE consisted of 90-min of continuous cycling at 90%–100% of the predetermined first lactate threshold, while SIE consisted of 6 sets of 30-s all-out cycling at a resistance of 0.075 kg·kg−1 body mass, with 4-min rests between the sets (Figure 1A).

The study's sample size was small and the period studied fairly short, but they did measure the levels of several thousand proteins.