A dedicated arm day workout adds direct biceps, triceps, and forearm volume beyond what push and pull days provide, using both bicep heads and all three triceps heads across the session. The routine below covers the long head vs short head distinction for biceps, the three triceps heads, and superset-based arm day workouts.[1][2][3]
Do You Need a Dedicated Arm Day?
Push and pull days already train biceps and triceps indirectly: every row and pull-up hits the biceps, every press and dip hits the triceps. For most lifters this indirect volume is enough. A dedicated arm day earns its place once your priority shifts specifically to arm size, since it adds direct isolation volume without extending your push or pull sessions. It fits well alongside how many sets per muscle group per week guidance, or as an add-on day in a bro split workout routine.
Biceps: Long Head vs Short Head
The biceps has two heads, and most lifters only train one angle without realizing it:[1][2][3]
- Long head: runs along the outer arm, stretched most when the arm is positioned behind the torso. Incline dumbbell curls and behind-the-body cable curls emphasize this head, and it contributes the most to bicep “peak.”
- Short head: sits on the inner arm, emphasized when the arm stays in front of the body. Preacher curls and concentration curls target this head, and it adds width to the bicep when viewed from the front.[1][2][3]
A standing curl trains both heads roughly evenly, but adding one incline and one preacher variation to a session covers both angles more thoroughly than any single curl variation alone. A spider curl is another supported option when you want the chest on an incline bench and a clear stop rule for shoulder drift or a shortened lowering phase. For the full grip-and-shoulder-position selection matrix, see bicep exercises.
Triceps: All Three Heads Matter More Than You Think
The triceps makes up roughly two-thirds of upper arm mass, more than the biceps, which makes it the bigger lever for visible arm size:[1][2][3]
| Head | Emphasized by | Role |
|---|---|---|
| Long head | Overhead extension | Crosses the shoulder joint, needs an overhead stretch to fully train |
| Lateral head | Pushdown, close-grip press | Gives the outer “horseshoe” shape |
| Medial head | Pushdown, close-grip press | Works alongside the lateral head in most pressing |
Since the long head needs an overhead position to be fully stretched, an arm day that only does tricep pushdowns leaves it undertrained. Include one overhead extension every session. For the full head-by-head selection matrix, see tricep exercises. A hammer curl is a useful addition on the biceps side, since its neutral grip also trains the forearms. A Zottman curl adds a controlled palms-up ascent and palms-down lowering phase when you want the grip transition itself to be part of the exercise. For a dedicated forearm session covering flexors, extensors, rotation, and grip endurance as four separate targets, see the forearm workout guide.
Superset-Based Arm Day Workout
Pairing a biceps exercise with a triceps exercise lets one muscle rest while the other works, cutting rest time without cutting volume.[1][2][3]
| Superset | Exercise A | Exercise B | Sets |
|---|---|---|---|
| 1 | Barbell curl | Close-grip bench press | 4 |
| 2 | Incline dumbbell curl | Skull crusher | 3 |
| 3 | Preacher curl | Triceps pushdown | 3 |
| 4 | Hammer curl | Diamond push-up | 2 |
Rest 60-90 seconds between supersets, moving straight from A to B with no rest in between.[1][2][3]
Standard Arm Day Workout (Non-Superset)
| Exercise | Sets | Reps |
|---|---|---|
| Barbell curl | 3 | 8-10 |
| Incline dumbbell curl | 3 | 10-12 |
| Preacher curl | 2 | 10-12 |
| Close-grip bench press | 3 | 8-10 |
| Overhead triceps extension | 3 | 10-12 |
| Triceps pushdown | 3 | 12-15 |
Let the Plan Cover Every Angle
Making sure both biceps heads and all three triceps heads get trained across the week, without over-scheduling arm volume on top of push and pull days, is easier with a plan built around your full split. Your PT’s AI plan generator fits a dedicated arm day into your schedule and balances it against the indirect volume you’re already getting.
References
- The mechanisms of muscle hypertrophy and their application to resistance training. Sports Medicine (2016)Back to claim
- Muscle hypertrophy and strength gains after resistance training with different volume-matched loads: a systematic review and meta-analysis. Sports Medicine (2021)Back to claim
- The Importance of Muscular Strength: Training Considerations. Sports Medicine (2018)Back to claim
Frequently Asked Questions
- Is a dedicated arm day necessary, or do biceps and triceps get enough work from push/pull days?
- Push and pull days train biceps and triceps indirectly through compound lifts, which is enough for most lifters. A dedicated arm day is worth adding once your priority becomes visible arm size specifically, since it lets you add direct volume without extending push and pull sessions further.
- What's the difference between the long head and short head of the biceps?
- The long head runs along the outer arm and is stretched most when your arm is behind your body, so exercises like incline curls emphasize it. The short head sits on the inner arm and is emphasized more in exercises where your arm stays in front of your body, like preacher curls. Training both angles builds a fuller-looking bicep.
- How many triceps heads are there and does it matter for arm day?
- The triceps has three heads: lateral, medial, and long. The long head crosses the shoulder joint, so it's stretched most in overhead extensions; the lateral and medial heads respond well to pushdowns and close-grip pressing. Since the triceps make up roughly two-thirds of upper arm size, hitting all three heads across a session matters more for arm size than biceps work does.
- Are supersets effective for arm day?
- Yes. Pairing a biceps exercise with a triceps exercise (antagonist supersets) lets you rest one muscle while training the other, cutting session time significantly without reducing volume or intensity on either exercise. This is one of the most time-efficient ways to structure an arm day.
- How often should I train arms on a dedicated arm day?
- Once or twice a week, depending on how much other indirect arm work you get from push and pull days. If you already do 2 push and 2 pull sessions weekly, one dedicated arm day is usually enough on top; if you're on a lower-frequency split, twice a week fits better.