There are numerous approaches you can take to gaining muscle size and strength. If you’re just getting started in the weight room, a study published in The Journal of Sports Medicine and Physical Fitness offers interesting insight into workout program planning.
Thirty untrained men in the early 20s took part in a 10-week program that hit each muscle group once or twice a week. All subjects performed the same volume of training regardless of which group they were assigned to.
At the end of the program, the muscle thickness of elbow flexors increased an average of 1.73 mm in the once weekly group and 2.31 mm for subjects in the twice weekly group. Subjects in the twice weekly group also experienced greater increases in strength.

High-intensity interval training isn’t restricted to treadmills and bikes. Your upper body can also get in on the action. Consider the findings of a study on amateur boxers published in the Journal of Strength and Conditioning Research.
Eighteen experienced male boxers added 3 rounds of all out punching to their regular workouts for 4 weeks. Three times each week, these 2-minute sessions consisted of 14 sets of 3 second all out punches to a bag with 10 seconds of rest.
Compared to subjects who didn’t add the interval punching protocol to their workouts, those who did were able to increase punching force and better maintain punching frequency throughout a 3 round fight.

A couple weeks back, we looked at the muscle mass gains from creatine and glycogen loading. A study published in the journal Medicine & Science in Sports & Exercise tests the performance potential experienced cyclists might experience from loading and carbohydrate loading.
Eighteen well-trained male cyclists loaded with 20 grams of creatine for 5 days followed by 3 grams for 9 more days. Some received a placebo instead. Then they raced a 120 km time trial with 6 different sprints of 1 to 4 km performed every 10 km followed by an uphill ride to fatigue.
After this intervention, subjects consumed 6 or 12 grams of carbohydrates per kg of body weight before competing in 2 more trials. Creatine and moderate carbohydrate loading improved power, and the larger carbohydrate load improved power in the final 1 km sprint. Creatine and the 12 gram carb load increased powder during 4 km sprints. That could help competitors in their sprint to the finish line.