Lifting weights for just 3 seconds a day can improve muscle strength

Holding dumbbells at maximum weight for 3 seconds is tiresome. So this is extreme version of high intensity training when one always do exercises to the point of failure.

It is surprising that doing just one repetition works. A typical recommendation with high intensity training is to select weight so one can do 5-12 repetitions to the point of failure. The actual number depends on goal (strength or muscle size), genetics etc. I guess the college students where not trained previously so this worked.