If you’re trying to gain muscle to bulk up, the key is to increase your calorie intake along with a proper exercise regimen. For many, this can be challenging when busy and active lifestyles make it hard to eat enough. It might be tempting to reach for any source of extra calories or resort to supplements in an effort to add muscle, but these aren’t always the healthiest or most effective strategies. Still, there are things you can do to achieve healthy weight gain for better military fitness.