It is common for one frequently used muscle group to get exhausted before you work through all your exercises. You can fix this by performing an isolation-type exercise, such as straight-arm pulldowns, that do not emphasize the bicep muscles as much. Your lats will already be tired, allowing your biceps to keep pace with them as you exercise.XL Test Plus Keep in mind that any muscle-building routine you undertake is only effective if it makes you stronger. Being stronger means that you should slowly be able to increase the amount of weight you are lifting in each exercise. When you just begin, you should be able to lift about 5% more every few workouts.