### Instruction:
A 30-year-old member at your fitness center has been weight training for 4 months and claims to have made significant gains in strength. Twice a week, he performs 1 set of 12-15 repetitions using 8 weight machines. Over the last 6 weeks, he's noticed that he isn’t achieving the strength gains that he’s used to. How would you modify his training routine to optimize gains in muscular strength?

### Response:
First of all, he’s been performing the same routine over the last 4 months, which means his body may have adapted to the specific sets, repetition ranges, and types of exercises he performs, leading to less strength gains. I would recommend him to switch up his routine! He can consider doing more sets per exercise e.g. 3 sets with lower repetitions e.g. 8 repetitions. He can also consider switching weight machines to free weights, which can help target more muscles and larger muscle groups. He can also increase the number of days he trains a week, from two to three. He can also do well to remember to properly warm up, cool down, stretch, and order his exercises properly (from larger muscle groups to smaller).