Tabata et al.[1] found in the mid-1990s that just 2-4 minutes of "high-intensity intermittent training may improve both anaerobic and aerobic energy supplying systems significantly." This was popularized as "Tabata training" 20+ years ago. I generally believe that brief bouts of exercise can be very beneficial, especially because they're easier to do consistently over the long-term vs. more time-consuming routines. F…
I think for the average person, looking too carefully at individual studies is failing to see the forest for the trees. Basically any time we do a study which asks "Is doing a bit more exercise better for you?" the answer is yes. Like doing a single walk around the block every week is better than doing none. Even five minutes of exercise is better than zero. But obviously these have much less positive impact than sev…
Unfortunately, it's people at both ends of the fitness curve that have to be careful about increased exercise frequency/intensity. On the less-fit side, the primary concern is accumulating minor injuries that reduce capacity for exercise even further leading into a downward spiral.