If you’re super fit, 6 months of grinding will make little difference in your physique or performance, but 6 months of lying around will make you frail. Fitness is funny like that. 

Fortunately, however, it’s much easier to maintain muscle and strength than many people realize.

In a study conducted by scientists at The University of Alabama at Birmingham, two groups of subjects (20-to-35 and 60-to-75 years old) did three 9-set strength training workouts per week for four months (Phase 1), and then were assigned to one of three groups for the next eight months (Phase 2):

  1. No exercise at all
  2. One 9-set weightlifting workout per week (⅓ of the previous volume)
  3. One 3-set weightlifting workout per week (1/9 of the previous volume)

In the end, the results looked like this:

  • Everyone gained significant amounts of muscle and strength in Phase 1.
  • Everyone who stopped training in Phase 2 lost muscle and strength (of course) but, by the end of Phase 2, they were still bigger and stronger than they were at the beginning of Phase 1.
  • The younger people in groups two and three above continued to gain significant amounts of muscle and strength in Phase 2.
  • The older people in groups two and three lost muscle but not strength in Phase 2.

This isn’t a lone outlier result, either. 

Consider a study conducted by scientists at the University of Alberta with 18 varsity female competitive rowers that began with 10 weeks of performing three full-body strength training workouts per week, with each workout consisting of six exercises and 24 sets. 

After this 10-week phase, the participants did one-rep max strength assessments on each of the six exercises, and then were split into two groups:

  1. One full-body strength training workout per week consisting of the same six exercises and 22 sets
  2. Two full-body strength training workouts per week consisting of the same six exercises and 44 sets

Six weeks later, whole-body strength was assessed again, and both groups had gained strength in two of the exercises and maintained strength in the four others. 

That’s right—super-fit women who went from 72 to just 22 sets of strength training per week still progressed on two exercises and maintained their strength (and thus muscle) on the rest.

So, here’s what we can take from these studies and several others like them:

  1. If you’re new to strength training, just a few sets of the right exercises (a balanced mix of upper- and lower-body compound exercises) taken close to muscular failure per week is enough to gain muscle and strength.
  2. If you’re an experienced weightlifter, just 3-to-6 sets of the right exercises taken close to muscular failure per week is enough to maintain muscle and strength.