A training program can help turn those extra calories into muscle, instead of just fat. You'll want to combine both weight and cardio training. Be prepared to work out at least five days a week to see maximum benefits. You’ll need to cut down your long distance cardio program if you are trying to gain weight. Long runs, for example, can burn up many of your stored calories. Instead, go for short, 15-minute cardio interval programs or incorporate sprints into a weight routine. Talk with a personal trainer and develop a specific weight workout plan that suits your goals. You’ll likely need to alternate very heavy lift days with lighter ones. Expect to spend at least 45 minutes at each session. It is quite possible that your trainer will also instruct you to train in intervals, performing a number of exercises in sets. You can get your diet and exercise program to work together by making good use of your “workout window.” Make sure to eat protein and carbs immediately before and after working out. You may be tempted to continually push yourself without a break for the full month. This can backfire and result in illness or injury. Instead, make sure to incorporate exercise rest days, diet cheat days, and just general relaxation periods. Getting at least eight hours of sleep a night is also important.

Summary:
Train hard. Limit your cardio. Follow a weight lifting plan. Let your body rest and recover.