The Transition Workouts, created by NSCA trainer Nick Clayton, C.S.C.S. will help you put on more muscle after you leaned out for the summer.
This is the advanced plan. You can find the beginner plan here and the intermediate plan here. For all three plans, the exercises start with the most difficult (highest degree of technique required and most amount of muscle mass used, like squats and bent-over rows) and progress to easier ones (isolation moves that require a lower degree of technique like calf raises and triceps rope pulls).
"The advanced group performs a larger variety in regards to exercise intensity/load—Meaning, they may perform squats in the strength range (3-6 reps), followed by hypertrophy (8-12), and finally muscular endurance (12+)," says Clayton. "This variation provides a great degree of stimulus to all muscle fibers. This degree of variety is beneficial to advanced lifts and often necessary to see continual gains."
Complete these workouts each week on non-consecutive days. Continue to eat right and you'll see muscle definition in no time. Just watch your form: "If you don't know how/can’t perform a back squat correctly, for example, either a) work on technique with a lighter load or b) select a less-technical variation of the back squat, such as the goblet squat," says Clayton.