The Muscles
The biceps brachii has two heads — the long head and the short head. The long head forms the outer portion of the upper arm and is responsible for the peak when the bicep is flexed. The short head forms the inner portion and contributes to overall width and fullness. Both heads flex the elbow and supinate the forearm — rotating the palm upward — which is why the twisting motion in a dumbbell curl is not just style, it is the correct way to fully engage the muscle.
Beneath the bicep sits the brachialis — a separate muscle that also flexes the elbow but lies deeper, pressing against the underside of the bicep from below. A well-developed brachialis pushes the bicep upward, creating a higher, more prominent peak regardless of genetic structure. It is trained most effectively with a neutral grip — the hammer curl — and is one of the most underrated additions to arm training.
The forearm flexors run along the inside of the forearm and flex the wrist and fingers. The brachioradialis runs along the outside of the forearm toward the elbow and is the largest forearm muscle — trained in reverse curls and hammer curls. Both forearm groups receive significant secondary work in every pulling and curling exercise, which is why direct forearm training can be brief.
The Most Honest Muscle in the Gym
Walk into any gym at any time of day and you will find someone doing bicep curls. Not deadlifts. Not rows. Not pull-ups. Bicep curls. It has been this way for as long as gyms have existed and it will be this way long after the rest of fitness trends have come and gone. There is something universal about the bicep — it is visible, it is immediately recognisable as a sign of training, and it photographs extremely well. Nobody's posterior deltoid went viral. The bicep has its own economy.
I was not immune to this. The first time I picked up a Flex magazine and saw what a developed arm looked like, I wanted to go out immediately and buy a barbell set. I was young. That is entirely the correct response. The bicep is legitimately one of the best-looking muscles on the human body when properly developed — the double peak when fully flexed is one of the most striking things in fitness. It is also, for the record, largely genetic. The double peak is determined by the length of the muscle belly and the structure of the tendon attachment. Training can build the size of the peak but cannot create the double peak where the anatomy does not support it. Knowing this will save years of frustration and a great deal of unnecessary volume.
The Problem
The bicep is a small muscle. It is genuinely, objectively small compared to the back, the chest or the legs. The amount of training volume most people devote to it is wildly disproportionate to its size and its capacity to recover. Ten sets on the barbell, eight sets on the cable, six sets on the preacher bench, a few more on the machine because you can load more weight — and then wondering why your elbows hurt and you cannot fully straighten your arms the next day.
Being unable to straighten your arms the day after training biceps is not a sign of a good session. It is a sign you did too much. DOMS — delayed onset muscle soreness — tells you the muscle was worked. It does not tell you it was worked well. The bicep responds to focused, moderate volume, heavy enough to create an adaptive stimulus, followed by adequate recovery. More sets do not produce more bicep. They produce more fatigue and slower progress.
Three exercises. That is the entire programme. After a back session — which has already worked the biceps as a secondary muscle through every row and pull-up — pick up a barbell, do your sets, and go home.
Biceps — Three Exercises
Barbell Biceps Curl
The barbell curl has built more biceps than every cable attachment, machine and resistance band combined. It allows maximum loading, trains both heads simultaneously and keeps the wrists in a supinated position throughout. Elbows fixed at the sides, full range of motion, controlled on the way down. Do this after a back session when the biceps are already warm. Three to five sets of eight to twelve reps. You can genuinely go home after this and the session is complete. Anyone who tells you otherwise is selling something.
Dumbbell Biceps Curl
Where the dumbbell curl earns its place is in the rotation. Start with a neutral grip — palms facing each other — and as you curl, rotate the wrist outward so the palm faces the ceiling at the top. This is supination, and it is the second function of the biceps alongside flexion. A barbell locks the wrist in position; a dumbbell lets you use the full movement the muscle is designed for. Can be done seated on a flat or incline bench to remove momentum entirely. Three sets of ten to twelve reps each arm.
Dumbbell Concentration Curl
Sit on a bench, lean slightly forward, rest the back of the upper arm against the inner thigh. Curl. That is it — nowhere to go, nowhere to cheat, no momentum possible. Arnold Schwarzenegger credited this exercise with his bicep peak and it deserves the credit. Done correctly it crucifies the bicep in the best possible way. Done incorrectly — with swinging, half range, or too much weight — it is pointless. Use less weight than your ego wants. Full range. Squeeze at the top. Three sets of ten to twelve reps each arm.
The Cheat Curl — Occasionally, Not Always
The cheat curl — using a slight body swing to initiate the movement and get a heavier barbell moving — is a legitimate training technique in the right hands. Dorian Yates used it. Serious lifters have always used it. The logic is sound: if you can curl 30kg with strict form, you can handle 40kg with a controlled cheat, which overloads the bicep at the point in the range where it is strongest and creates a greater stimulus.
The key word is controlled. A deliberate, measured use of momentum to handle slightly more weight than strict form allows — that is a technique. Swinging the entire upper body to jerk a weight you cannot control — that is an injury. Every now and again, not every session. And only once the strict form version is genuinely mastered. Not before.
Forearms — Brief, Effective, Unfashionable
The forearms already receive significant work in every pulling movement — deadlifts, rows, pull-ups, every curl variation. The grip alone provides isometric loading through the entire back session. Direct forearm work is therefore a brief addition, not a major training focus. Two exercises, done at the end of an arm session. Both are old school. Neither is fashionable. Both work.
Barbell Wrist Roll and Curl
Hold a barbell with palms facing up. Let it roll down to the fingertips — controlled, deliberate, fingers extending. Then curl the fingers back up to a full grip and flex the wrists upward. That is the movement. Simple, effective, almost entirely absent from modern training because it does not look impressive and nobody films it. It works the forearm flexors, the finger flexors and the grip simultaneously. Two to three sets of fifteen to twenty reps. Light weight. This exercise does not need to be heavy to be effective.
Reverse Curl
A barbell curl with an overhand grip — palms facing down — rather than underhand. This removes the biceps from the movement almost entirely and places the load on the brachioradialis, the large muscle running along the outside of the forearm toward the elbow. It also trains the brachialis. Another exercise that is rarely seen in commercial gyms, rarely programmed by influencers and consistently used by people who have serious forearm development. Two to three sets of ten to twelve reps.
Neither of these exercises will appear on anyone's social media. They are not photogenic. They do not produce a pump that photographs well. They require patience and light weight and look like nothing is happening. They are exactly the kind of exercise this site exists to recommend.
