If you're 6', about 160 lb, and really want to build muscle, you're gonna need to gain weight. The amount will depend on your strength and physique goals. Make sure that you're doing stuff like heavy squats, deadlifts, bench presses, overhead presses, chinups, rows, power cleans, dips, etc. Sprints are excellent, too. Most importantly, eat A LOT of protein. Try to get at least 1 g per 1 lb of bodyweight each day. Best of luck.
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