While it may be harder to build muscle, it's not impossible. One of the largest hurdles you need to overcome is testosterone production.
As you age, your body produces less testosterone than when you were in your teens and early 20s.
Even so, there are ways to boost your testosterone naturally. Remember, you must eat right, lift heavy and get enough rest...
Eat right: Monounsaturated fats may increase testosterone levels. Nuts, olive oil, and peanut butter are good sources.
Lift Heavy: Use heavy weights doing 3 to 5 sets of 6 reps using approximately 85% of your one rep max. Rest at least 1 minute between each set.
Get Some Rest: Finally, get some rest! Inadequate sleep could decrease testosterone levels!
