Evidence Based Bicep Training.

THE BRIEF
Evidence Based Bicep Training

As always, everyone will have their opinion, “all you need are compounds bro” or you will have the dude performing every single curl variation, every workout.

We will be taking a different approach, instead looking at whether you need bicep isolation work on top of compound movements and the mechanisms behind what drives muscle (specifically) bicep growth, to determine the most effective exercises for you to incorporate into your training program.

What You'll Find Out Below

• 💡 Do You Need Bicep Isolation Work?

• 🧬 Selecting Evidence Based Bicep Exercises

• 💪 Incline Curls vs Preacher Curls

• ✍️ TLDR: Key Takeaways & Practical Applications

JUST COMPOUNDS?
Do You Need To Do Bicep Isolation Work?

You will have met the guy in the gym who claims all you need is compound back work to get big pipes, fortunately for him, he’s just got those big arm genetics. Ever seen that guy at the park with massive calves and does zero exercise, yet you spend 3 sessions a week boring yourself to death with calf raises? That’s just the hand you're dealt and that’s how it works, nevertheless, we can always improve where we are at!

Your biceps do work hard during compound pulling movements such as rows and pullups, but could we get more growth from adding in direct bicep isolation work?

Compound Pulling vs Bicep Isolation was put to the test in a study by (Mannarino et al., 2019) using unilateral dumbbell rows and unilateral dumbbell curls over an 8 week program in 10 untrained men to assess bicep growth results and 10RM (Repetition Max) performance in each movement.

Training sessions were twice per week, with weeks 1-4 using 4 sets of 8-12 repetitions and weeks 4-8 using 6 sets with the same repetition scheme.

As you can see from Figure A above, the bicep curl grew the biceps more with 11.06% growth increase, where as the dumbbell row grew the biceps 5.16%.

As for the 10RM testing, the subjects got stronger at the movement they trained, ie. the dumbbell row group got stronger than the bicep curl group at dumbbell rows and vise-versa.

Note: This has been my personal experience also, I spent year’s just performing compound movements, getting stronger at them and increasing my chest and back size, with little marginal improvements in arm size. I only began seeing improvements in my own bicep growth by following the guidelines outlined below.

A MESSAGE FROM OUR PARTNER

Participate in running research with RunDot and get two free months of run training

What is The RunDot Project?

It is an annual research initiative that uses optimized run training to help runners reach their true potential.

Why should you join?

RunDot athletes improve their running abilities, on average, 3.2x more than non-users, and experience performance improvements in 30% less training time.

Qualified participants also receive 2 free months of run training.

Do you qualify?

• You are a good fit if you check these boxes:

• You train with a GPS-enabled device

• You have not used RunDot or TriDot in the last 12 months

• You are not a professional runner

• You are enthusiastic and motivated to accomplish your running goals

Do you meet these criteria?

Join the 2024 RunDot Project. Learn more and apply here.

WHERE DO YOU START?
Selecting Evidence Based Bicep Exercises

Now we have established that if you really want to maximise your potential bicep growth, you should include some direct bicep work. Where do you start? The variations are endless.

In order to pick the most evidence based bicep exercises, we must first understand how they work and function.

Unlike a lot of other muscle groups, the biceps have a sort of unique tension-length relationship, where the biceps can produce the most active tension when they are very stretched, and much weaker when shortened. As we know mechanical tension is a primary driver in muscle growth (along with volume and proximity to failure of course) this should come into consideration when selecting an exercise.

Not only this, the growing body of scientific evidence shows that training a muscle at longer lengths promotes greater hypertrophy, we have already covered this and presented the evidence when it comes to the hamstrings and triceps.

This was the subject of a study by (Sato et al., 2021) who took 32 non trained adults and the effects of unilateral (single arm) dumbbell preacher curls in two different portions of the lift. One group performed the curl at long muscle lengths in the initial ROM (0°-50°) and the other group performed the curl at short muscle lengths (80°-130°). Both groups performed 50° range of motion in the curl.

The results of the 5 week study showed that the group performing the movement in the long muscle length portion of the range of motion saw upto 3 times more bicep growth and the short muscle length group. Not only that, but even though the long muscle length group saw 3 times more growth, they had to use less weight.

The above study had its findings verified by another recent(ish) study by (Pedrosa et al., 2023), who again used the single arm dumbbell preacher curl as the exercise of choice. 19 young woman were split into two groups, a long muscle length group performing (0°–68°) and short muscle length group performing (68°–135°).

There finding showed that bicep growth was greater in the long muscle length group and that full ROM 1RM strength increased more in this group also.

So with all this information about tension in the biceps at long muscle lengths, you might automatically think incline curls are the best option. Afterall, you stretch them more on a 45° incline bench. There is one pitfall however, incline curls don’t allow for tension at the bottom of the movement, even though they provide a good stretch.

The next study we will look at, carried out in 2023, compared Preacher Curls to Incline Curls 👇…

TWO POPULAR OPTIONS…
Incline Curls vs Preacher Curls

Incline curls vs Preacher curls were compared in a study by (Zabaleta-Korta et al., 2023). They had 38 woman take part in a 9 week training plan, split into two groups, performing either dumbbell preacher curls or 45° incline curls.

Both groups performed 4 sets at their 12RM to volitional failure, 3 times per week. Note: the authors of the study had the incline curl group only lift to the 90-110° point in the range of motion, although this still tests the lengthened position idea.

The results showed no significant difference in muscle growth between the groups, although, the preacher curl group saw a slightly higher percentage of muscle growth in all 3 measurement areas of the bicep than the incline curl group, with the area near the elbow seeing significantly more growth, and the other two area’s seeing no significant difference in growth.

So, we now know that the stretch and training at long muscle lengths are important to maximise muscle growth, but so is having tension on the muscle at long lengths.

The classic barbell and dumbbell curls don’t provide either a stretch on the bicep or tension on the biceps in the bottom (initial) part of the lift, scoring them out as ineffective according to science.

Preacher curls allow for tension in the lengthened position compared to incline curls, however don’t offer as good a stretch on the bicep.

TLDR
Key Takeaways & Practical Applications

• If you want to maximise your bicep growth you should be incorporating some bicep isolation work to your training program.

• Studies have shown that training a muscle at long lengths can provide a greater stimulus for muscle growth, provided there is tension on the muscle at those lengths.

• The preacher curl offers tension at the bottom (stretched) position of the lift, whereas the incline curl offers no tension at the bottom but a greater overall stretch.

• Barbell and dumbbell curls are suboptimal for bicep development as they don’t provide any tension at the bottom of the movement and no stretch.

• As always, train to or within close proximity to failure, ensure you are getting enough volume in and ideally train them twice per week.

At the end of the day, if all you did was preacher and incline curls you would get bored quickly. Although maybe not optimal, I still enjoy doing your standard dumbbell curls and hammer curls. These provide variation to your training and who doesn’t love lifting a bit more weight just for the sake of it, plus I always find I get a good “pump” from your standard hammer curls.

However, if you are serious about growing your biceps, I’d focus on performing exercises that check the box’s of tension at long lengths and allowing for a deep stretch at the bottom of the movement.

Till next time,
Keep Training & Keep Pushing.

Mark ✌️