What is RIR / Reps in Reserve ?

When it comes to lifting weights for building muscle we just need to do enough that we stimulate our muscles to adapt. This does not mean go to complete failure where it feels like your muscles are going to explode and you cannot do any more reps. All you have to do, according to the latest research is perform a set with 3 reps in reserve to get the effect.

This means if you doing an exercise for 10 reps would get you to complete failure then you will get the majority of muscle building benefits by stopping at 7 reps. So when training you generally should leave 1-3 reps in reserve when performing a set. Will sets still be tough? Yes, but you should never grind out or force reps.