The bicep isn't the primary muscle being used, but it isn't relaxed during the exercise either, and at a beginner to intermediate level, it simply isn't necessa

The bicep isn't the primary muscle being used, but it isn't relaxed during the exercise either, and at a beginner to intermediate level, it simply isn't necessary to target the bicep specifically. That's what makes these compound exercises better than others; they involve lots of different muscles other than the primary ones.