What's the time threshold for a drop in performance when taking a break from training?

Question

Whenever I go on vacation, the dilemma in my head is, should I try to work out there? Or just take a break from everything and resume when I get back.

The worry is that a break would cause some backward progress in strength, depending on how long the break is.

I do know that I have hit PR's on first days back at the gym after about 2 weeks of no lifting, which is awesome. But if I had waited longer, would it have been different?

I'm wondering if there is a scientifically found time period that the body can generally maintain strength levels for, after which there is a performance hit.

I'm mainly talking about this in a strength/powerlifting context, but I guess any info on the same idea with regard to general fitness (i.e. endurance/stamina, coordination) would be nice.

Answer 1

Strength performance will follow a supercompensation curve with an amplitude and period that corresponds to your level of advancement.

From Canmore Ski club (I liked their graphic):

It's unlikely that your two-week vacation made you stronger, but time off (even time off that makes you weaker!) is sometimes called for in order to heal nagging injuries. Perhaps there was an overuse injury getting in the way of your PR previously.

In most strength programs, novices have a very quick recovery/supercompensation period--one to two days. Intermediate strength programming is generally designed around one week supercompensation periods. Advanced trainees (as I understand it) are those for whom weekly recovery is not enough, and so use programs designed for gains in a given area over a month or longer.

I am less familiar with the numbers for strength loss after supercompensation (the gentle downward slope at the far right of the graphic). I do know that the loss of new strength is faster than the loss of long-held strength. Example: If you deadlift around 300 for a couple years, then stop lifting for a week or two, the loss will be less than if you just achieved a 300-pound deadlift for the first time ever, then immediately take a break.

Two sources I am not very familiar with, Anabolic minds and Building Muscle 101 both put forth anecdotal evidence that strength loss is noticeable after as short as a week, and significant setbacks after three or four.