Don't use training at home an excuse for lack of muscle building progress. While it may be easier to switch up your routine and include a wider variety of exercises at a gym, there's no reason why you can't build muscle at home. How fast you build muscle depends on several different factors. If you've been training at a high-intensity for several months or even years, you may find gains to be slower, but if you train hard and eat right, you can build noticeable muscle mass working out at home.
Split your body in half -- upper body and lower body -- and train each half twice a week. Your schedule could be upper on Monday, lower on Tuesday, rest on Wednesday, upper on Thursday, rest on Friday, lower on Saturday and rest on Sunday. Any schedule works though, provided you're not hitting the same muscle groups on back-to-back days.
Make squat variations the foundation of your workout. In "The Bodyweight Workout Guide," strength coach Nia Shanks advises that if regular squats are too easy, try more challenging variations such as single-leg squats; squats holding the bottom position for three seconds; timed squats, where you perform as many squats as possible in 20 to 30 seconds; and pistol squats.
Add hamstring moves to your lower-body workouts too. The most basic hamstring move is the glute bridge, performed by lying on your back on the floor. Bend your knees to 90 degrees, dig your heels into the ground and lift your hips up. For a tougher variation, lift your feet onto a bench or chair and do the move, or try it single-legged by just having just one heel in contact with the ground and the other foot elevated.
Learn how to perform pull-ups and push-ups for your upper-body sessions. For pull-ups, you'll need a doorway pull-up bar, which can be purchased from most sporting goods stores. Pull-ups work your back and biceps, while push-ups work your chest, triceps and shoulders. Between those two exercises, you have your entire upper body covered. Include different variations though; try wide and narrow-grip pull-ups or switch between palms facing you and palms away from you. For push-ups, you can change hand spacings as well; use a slow tempo, add a clap at the top of each rep, or work your way toward a one-arm push-up.
Buy a set of resistance bands to give you more variety. Get a good quality set with at least three to four different levels of band. Using these, you can perform leg extensions, hamstring curls and lateral walks in your leg sessions. You can add them to your squats as well. They can be used on pull-ups and push-ups and for exercises like biceps curls and triceps push-downs.
Increase your workload week by week. Gaining muscle revolves around you gradually pushing your body to do more and more. In week one of your training, coach John Cortese recommends performing five bodyweight exercises for three to four sets of eight to 15 repetitions each. In week two, bump this up to six to eight exercises for three to five sets of 10 to 20. In week three, increase this again to eight to 10 exercises for four to six sets of 15 to 25 reps each. Then in week four, do five to seven sets of 20 to 30 reps each on 10 to 12 exercises.
Eat, eat and eat some more. The main reason people don't gain muscle, or at least gain muscle slowly, is lack of food rather than training intensity. You need to be eating enough calories for the scale to be going up, according to trainer Nate Green. Green also advises basing your diet around good sources of protein, vegetables, fruits and carbs.
Design your own home gym. It may seem extravagant, but building your own workout space could help you make faster gains by increasing your motivation to train. Dumbbells and stability balls are all versatile and relatively cheap. A kettlebell or two may also be a good idea, as would a medicine ball and adjustable barbell set. If space permits, you could buy a squat rack, bench and Olympic weights set for your garage.