some say up reps high volume, your diet and cardio drive fat loss not 20 rep sets vs 8-12
100% true
BUT
Some guys, maybe most, grow muscle better on higher reps for leg training.
Acute and long-term effects of resistance-training regimens with varied combinations of high- and low-intensity exercises were studied. Acute changes in the serum growth hormone (GH) concentration were initially measured after 3 types of regimens for knee extension exercise: a medium intensity...
pubmed.ncbi.nlm.nih.gov
"Take a study from Japan that found that adding a set of high reps (25-35 reps) was best for boosting not only muscle size, but also muscle strength. The Japanese scientists had trained men do a leg workout twice a week for six weeks on a typical muscle mass gaining program that involved using moderate weight for 10-15 reps per set of leg presses and leg extensions.
After this 6-week training phase they separated the men into two groups: 1) a strength-training group, and 2) a mixed-training group.Both groups trained with a typical strength-training program that consisted of 5 sets of each exercise (leg press and leg extension) done with heavy weight for 3-5 reps per set with 3 minutes of rest allowed between sets for four weeks. The mixed-training group also performed one light-weight set of 25-30 reps done 30 seconds after the last set.
The researchers reported in the Journal of Strength and Conditioning Research that the group doing the 25-30 rep set not only continued to make gains in muscle mass, while the strength-training group actually had a slight loss in muscle mass, but they gained about 5% more strength than the strength-training group.
Although the scientists were unsure of the exact mechanism for the additional strength gains, it appears that the single set of higher reps provides an additional training stimulus that impacts strength gains. The higher growth hormone levels that comes with high rep training may have increased muscle size and strength gains."
The way you perform your reps can make a HUGE difference. Here's my breakdown on changes you can make to this crucial training variable.
www.jimstoppani.com
I know that is not comparing 20 reps for 8-12, but it's good to experiment a little, change things up, and see if new ways will work better. Experiment with reps, volume, different training programs. Give things a chance and see what works. It is doubtful that one thing works equally well for all persons, or that even one set thing works for one person as opposed to changing things up sometimes.