Like all muscles in your body, you can perform bicep exercises up to three non-consecutive days a week. If you're lifting heavy weights, (enough that you can only complete six to eight repetitions) you'll need at least two days of rest before you perform the exercise again. For this reason, you may only work your biceps once or twice a week. If you're goal is endurance/lean muscle, stick with one to three sets of 12-16 repetitions and at least one day of rest before you perform the exercises again. Keep in mind that you will use your biceps when performing chest and back exercises as well.
