Recruit and Contract
If you want to build your biceps, you must improve your ability to recruit and contract them.
When it comes to biceps, focusing on getting them strong often makes it more difficult to get them big. Going heavy can shift the tension away from the biceps. Practicing intense contraction of the target muscle is much harder to do when using heavy weights.
So when you're trying to fix lagging biceps, the first thing to do is work on constant tension to maximize the mind-muscle connection. The time spent doing it will be an investment in all the future biceps training you'll do.
Do This for 4 Weeks
Do every rep of your bicep work like this:
- Before even lifting the weights, tense the biceps as hard as you can, as if you were trying to flex it. That is the "principle of first tension" – the muscle firing hardest first is the one that'll receive the most stimulation in the set.
- Then when you lift and lower the weight, use a slower tempo. About 3 seconds up and down. This allows you to tense and flex the biceps as hard as humanly possible during every inch of every rep (during both the lifting and lowering portions). If you go faster it's harder to keep the muscle maximally tensed.
- During the lowering portion you should actually flex and tense your triceps too. Sounds weird, but it makes the eccentric (lowering) even harder, accentuating the eccentric.
- It's the best way to become really good at recruiting and contracting the biceps and you'll program your nervous system to do it, which will make the future heavier biceps work more effective.
- It stimulates muscle growth via an accumulation of growth factors and mTOR activation, but there's very little, if any, muscle damage. So you can (and should) do this type of biceps work multiple times during the week. Think 3-4 days a week. This will allow you to become even better at recruiting the biceps.
Remember, frequency of practice is the key to motor learning. Once you've spent some time training the biceps like this, you'll be able to switch to heavy lifting, but now the tension won't shift away from the biceps because you improved your capacity to recruit the muscle and keep it tensed.