If you're a guy who's already lifting weights, doing 4 workouts a week for 8 weeks will noticeably grow your thigh muscles — and it doesn’t matter whether you stick to the same routine or mix it up...

This study only looked at the front and side of the thigh—so we don’t know if doing more sets helps your front thigh or hamstrings grow more.

In healthy young men, performing resistance training twice a week for six weeks, using either 10 or 20 repetitions per set to failure, leads to similar increases in muscle thickness of the thigh muscle, and both training methods result in greater muscle growth than no training.

Among people who regularly lift weights, training until muscle failure for eight weeks leads to about the same increase in quadriceps muscle thickness as training with a small amount of reserve strength left, with both methods producing an average gain of 0.18 centimeters.

After 10 weeks of lifting weights, whether you rest 20 seconds or 2 minutes between sets, your thigh muscle gets about 15% bigger and you can lift about 40% more weight.

If you lift weights twice a week for 8 weeks and do the same total amount of work, your upper and middle thighs will get thicker — no matter what fancy technique you use.