5x5s are a strength training method.

It involves doing 5 sets of 5 reps for an exercise. You should focus on lifting AS MUCH weight as possible, and PROGRRESSIVELY OVERLOADING on each set.

These can be used in conjunction with a MUSCLE GAIN split, by performing the first exercise as a 5x5.

If possible, get a spotter to assist you with these lifts.

Related Questions:

1. What is progressive overload and how can I implement it?
2. What is the best split for muscle gain?