Quick Answer
The inside tricep (medial head) cannot be fully isolated, but you can shift more emphasis onto it by using a reverse (underhand) grip on pushdowns and presses, keeping your elbows pinned to your sides, and finishing your session with higher-rep sets (15–25 reps). The best exercises include reverse-grip cable pushdowns, close-grip bench press, skull crushers, and tricep dips. Keep total tricep volume to 10–12 sets per session and train twice a week for consistent gains.
Tricep Anatomy: Understanding the Three Heads
The triceps brachii sits on the posterior (back) side of the upper arm and is responsible for extending the elbow — straightening the arm. It makes up roughly two-thirds of total upper arm mass, which is why developing all three heads matters so much for arm size and strength.
Long head. The largest of the three, the long head originates from the infraglenoid tubercle of the scapula (shoulder blade). Because it crosses the shoulder joint, it is best targeted when the arm is raised overhead — such as in overhead tricep extensions. The long head contributes the most to overall arm thickness.
Lateral head. Located on the outer surface of the humerus (upper arm bone) above the radial groove, the lateral head is the most visible from the front and side. It dominates in exercises with an overhand grip and responds well to heavy loading in the 6–12 rep range due to its high proportion of fast-twitch muscle fibres.
Medial head. The smallest head, arising from the posterior humerus below the radial groove. It is largely covered by the long and lateral heads, which is why it rarely gets dedicated attention. Its origin and insertion run from the upper arm bone to the olecranon process of the ulna (the bony point of the elbow). Unlike the other two heads, the medial head is the only tricep head that remains active even during low-resistance elbow extension — effectively acting as the workhorse of the group.
All three heads share a common tendon that attaches to the ulna just past the elbow, which means every tricep exercise activates all three to some degree. The goal with inside tricep training is not isolation — it is emphasis.
To understand how tricep strength translates to sport performance, see our guide to strength training for runners and strength training for triathletes.
Why Train the Inside Tricep Specifically?
Elbow stability. The medial head is continuously active during all pushing and pressing movements, stabilising the elbow joint throughout the range of motion. A strong medial head reduces the risk of elbow strain and keeps pressing mechanics cleaner under load.
Fuller arm appearance. When the medial head is underdeveloped, the bottom of the tricep — just above the elbow — looks flat and narrow. Building the medial head fills out this area, creating a denser, more complete horseshoe shape from every angle.
Pressing strength carryover. Every press — bench, overhead, dip — relies heavily on the triceps at lockout. A stronger medial head means you stabilise load better through the full range, which translates directly into heavier lifts. See our overview of the 10 components of physical fitness for more on how muscular strength underpins performance.
Correcting imbalances. Most standard tricep programmes focus on overhand pushdowns and skullcrushers, which predominantly work the lateral and long heads. If your outer tricep looks well developed but the inner portion feels soft or underpowered, targeted medial head work is the fix.
The 7 Best Inside Tricep Exercises
1. Reverse-Grip Cable Pushdown
This is the single most effective exercise for emphasising the medial head. Switching from the standard overhand grip to a supinated (palms-up, underhand) grip shifts the mechanical tension toward the medial head while reducing stress on the elbows. Attach a straight bar or EZ-bar to the high pulley. Stand back slightly and lean forward so your upper arm sits at roughly 90 degrees to your torso — this keeps tension on the tricep through the full range rather than just at lockout. Keeping your elbows pinned to your sides, push the bar down to full extension and hold the contraction for one second before returning slowly. Use a moderate load that allows 12–20 controlled reps.
2. Close-Grip Bench Press
The close-grip bench press is the best compound movement for the medial head and a strong starting point for any inside tricep session. Take a shoulder-width grip (or slightly narrower — hands about 30–40 cm apart). This grip reduces chest involvement and places the load more directly on all three tricep heads, with the close hand position increasing medial head activation as a stabiliser. Keep your elbows tucked at roughly 45 degrees to protect your shoulders and maximise tricep engagement. Lower the bar under control to the lower chest, pause briefly, then press to full lockout. Work in the 6–10 rep range with progressive overload for strength and hypertrophy.
3. Skull Crushers (EZ-Bar or Dumbbell)
Skull crushers — lying tricep extensions — are one of the most complete tricep exercises because they train the muscle through a longer range of motion than most pressing variations. To emphasise the medial head, lower the bar toward your forehead (not behind the head) and keep your upper arms vertical with elbows pointed at the ceiling. This elbow position reduces long head stretch and increases medial head demand. Dumbbells allow each arm to move independently, helping to correct side-to-side imbalances. Use a moderate weight for 10–15 reps; avoid ego-loading as form breakdown on skull crushers tends to load the elbows poorly.
4. Reverse-Grip Dumbbell Press
This is an underutilised press variation that prioritises the medial head by using a supinated (bicep curl-style) grip throughout the movement. Lie on a flat bench holding a pair of dumbbells with palms facing your shoulders. Press up to full extension, keeping your elbows relatively close to your body. The reverse grip takes stress off the shoulder joint compared to a standard press and places it squarely on the triceps, making it a useful option for those with shoulder discomfort. Work in the 10–15 rep range. Start with a lighter weight than you would use for a standard dumbbell press until you are comfortable with the grip.
5. Tricep Dips
Dips are an excellent bodyweight option that trains both the medial and lateral heads, particularly through the final degrees of elbow extension. For tricep emphasis, keep your torso as upright as possible and avoid leaning forward excessively (which shifts load to the chest). Extend fully at the top of each rep to maximally contract the tricep. Bench dips are a good beginner option; parallel bar dips allow heavier loading via a dip belt when bodyweight becomes too easy. Aim for 3 sets of 12–20 reps or add weight for strength-focused sets of 6–10 reps. See our guide to plyometric push-ups for more bodyweight pushing progressions.
6. Cable Concentration Tricep Extension
This single-arm cable exercise is excellent for correcting left-right imbalances and for reinforcing the mind-muscle connection with the medial head. Attach a single handle to a high cable pulley. Kneel or sit to the side of the machine and rest the back of your working arm on your inner thigh (similar to a dumbbell concentration curl). With your torso tall, extend at the elbow to full lockout, concentrating on squeezing the tricep hard at the bottom. Using an underhand grip further biases the medial head. Work in the 12–20 rep range with slow, controlled tempo.
7. Diamond Push-Up
The diamond push-up is the most accessible medial head exercise requiring no equipment — important for home training or gym warm-up. Place both hands on the floor with thumbs and forefingers touching to form a diamond shape, positioned under your chest. Lower under control with elbows tucking in, pause at the bottom, then press to full lockout. The narrow hand position concentrates the load on the triceps (particularly medial head) and reduces chest involvement substantially. If full-range reps become easy, elevate your feet to increase load or add a weighted vest. For a complete no-equipment arm programme, see our no-equipment bicep workout and our guide on how to work out biceps without dumbbells to pair with these tricep moves.
Inside Tricep Exercise Summary
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| Exercise | Equipment | Best Rep Range | Medial Head Emphasis | Key Tip |
|---|---|---|---|---|
| Reverse-Grip Cable Pushdown | Cable machine | 12–20 | ★★★★★ | Step back, lean forward, elbows pinned |
| Close-Grip Bench Press | Barbell + bench | 6–10 | ★★★★☆ | Elbows at 45°, full lockout each rep |
| Skull Crushers | EZ-bar or dumbbells | 10–15 | ★★★★☆ | Lower to forehead, upper arms vertical |
| Reverse-Grip Dumbbell Press | Dumbbells + bench | 10–15 | ★★★★☆ | Supinated (curl-style) grip throughout |
| Tricep Dips | Parallel bars or bench | 12–20 (BW) / 6–10 (weighted) | ★★★☆☆ | Stay upright, extend fully at top |
| Cable Concentration Extension | Cable machine | 12–20 | ★★★★★ | Underhand grip, full extension, slow tempo |
| Diamond Push-Up | Bodyweight | 15–25 | ★★★☆☆ | Hands under chest, elbows tuck inward |
How to Structure Your Inside Tricep Workout
Because the triceps are a relatively small muscle group that gets significant secondary work during any chest or shoulder session, it is easy to overtrain them. Research and coaching practice both suggest keeping total tricep volume to no more than 10–12 sets per session. Train them twice weekly with at least 48–72 hours between sessions.
Session structure. Begin with a compound movement (close-grip bench press or reverse-grip dumbbell press) while you have the most energy. These exercises allow you to move meaningful load and generate the most hypertrophic stimulus. Follow with a cable isolation movement (reverse-grip pushdown or concentration extension) at moderate weight and higher reps. Finish with a bodyweight or burnout move (dips or diamond push-ups) taken close to failure to maximise metabolic fatigue in the medial head.
Rep ranges and loading. The medial head has a higher proportion of slow-twitch fibres compared to the lateral head, meaning it responds better to moderate-to-high rep ranges. Heavier sets of 6–10 reps in compound movements will build strength, but the medial head gets its best stimulus in the 15–25 rep range, particularly on isolation exercises at the end of a session. Vary rep ranges across your training week rather than always defaulting to heavy, low-rep work.
Progressive overload. The same rule that applies to every muscle applies here: you need to consistently increase either the load, reps, or total sets over time. Track your weights and aim to add a rep or small amount of weight every 1–2 weeks on your key lifts.
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| Training Goal | Sets × Reps | Load | Rest Between Sets | Frequency |
|---|---|---|---|---|
| Strength | 4 × 6–8 | Heavy (75–85% 1RM) | 2–3 min | 2× per week |
| Hypertrophy (size) | 3–4 × 10–15 | Moderate (65–75% 1RM) | 60–90 sec | 2× per week |
| Medial head emphasis | 3 × 15–25 | Light–moderate (50–65% 1RM) | 45–60 sec | 2× per week |
| Endurance / tone | 3 × 20–30 | Light (40–55% 1RM) | 30–45 sec | 2–3× per week |
Sample Inside Tricep Workout (Gym)
This 30-minute session is designed to cover the full tricep with extra emphasis on the medial head. It can run on its own or at the end of a chest/push session when the triceps are already warmed up.
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| Order | Exercise | Sets × Reps | Notes |
|---|---|---|---|
| A1 | Close-Grip Bench Press | 4 × 8 | 2 min rest; progressive overload focus |
| B1 | Skull Crushers (EZ-bar) | 3 × 12 | 90 sec rest; lower to forehead |
| C1 | Reverse-Grip Cable Pushdown | 3 × 15–20 | 60 sec rest; lean forward, elbows pinned |
| D1 | Cable Concentration Extension | 2–3 × 15 each arm | 45 sec rest; underhand grip, slow tempo |
| E1 | Diamond Push-Up (to failure) | 2 × max reps | Burnout set; bodyweight only |
Common Mistakes That Stall Medial Head Growth
Always using an overhand grip on pushdowns. Standard overhand (pronated) pushdowns bias the lateral head. If every cable pushdown in your programme uses this grip, your medial head is being systematically undertrained. Rotate in reverse-grip sets or switch entirely for one session per week.
Partial range of motion. The medial head is most active through full elbow extension, particularly at lockout. Stopping short of full extension on pushdowns, dips, and presses means leaving the medial head’s peak contraction zone on the table. Focus on fully straightening the arm at the end of each rep.
Always training heavy and low rep. Heavy compound work is important for overall tricep strength and size, but the medial head’s higher slow-twitch fibre composition means it responds better to moderate-to-high rep ranges on isolation work. Finishing your session with 15–25 rep sets on cable exercises provides the stimulus this head needs.
Neglecting elbow position. Allowing the elbows to flare wide during pushdowns or presses reduces medial head tension and shifts load to the shoulders. Keep elbows tucked close to the body throughout all tricep movements.
Insufficient recovery. Because the triceps assist in all pressing movements — chest, shoulder, and tricep days — they can accumulate fatigue quickly. Training triceps directly after heavy chest work, then again the following day, is a common reason progress stalls. Ensure at least 48–72 hours between dedicated tricep sessions, and factor in any chest or shoulder work that also taxes the triceps. For more on structuring recovery into your programme, see our guide to physical fitness components.
Inside Tricep Training Without a Gym
You do not need cable machines or barbells to train the medial head effectively. Diamond push-ups are the most accessible medial head exercise available and can be progressed by elevating the feet, wearing a weighted vest, or slowing the tempo. Bench dips with feet elevated are a solid compound bodyweight option. Resistance bands can replicate the reverse-grip pushdown with a supinated grip — simply anchor the band overhead and perform pushdowns using a palms-up grip. For a comprehensive bodyweight arm programme, see our guide to at-home exercises without a gym.
If you are also working on upper-body endurance for sport, the exercise bike with arm workout guide covers how to combine upper and lower body conditioning efficiently, while upper body cardio without using your legs outlines options for arm-focused training days.
Inside Tricep Training for Runners and Cyclists
If you train primarily for running or cycling, dedicated arm work might seem unnecessary — but there are practical reasons to include it. Upper body strength training improves running economy by maintaining posture and arm drive at fatigue, particularly in the later stages of longer races. A well-developed tricep also helps with the pushing mechanics of trail poles and stabilises the upper body during hill running. Our strength training programme for runners and gym exercises for runners both include upper body work for exactly this reason.
For cyclists, arm and shoulder strength is critical for sustained power output in the aero position and for bike handling. The strength and weight training for cyclists guide covers the full picture of gym work for the bike.
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FAQ: Inside Tricep Workout
What is the inside tricep?
The inside tricep is the medial head of the triceps brachii — the smallest and deepest of the three tricep heads. It originates on the posterior humerus below the radial groove and inserts onto the olecranon of the ulna. It is the only tricep head active during low-resistance elbow extension, making it critical for elbow stability at all loads.
Can you isolate the medial head of the tricep?
Not completely — all three heads fire together during elbow extension. However, using an underhand (reverse) grip on pushdowns and presses, keeping your elbows close to your body, and training in higher rep ranges (15–25) creates more relative emphasis on the medial head compared to standard overhand-grip movements.
What are the best exercises for the inside tricep?
The most effective medial head exercises are: reverse-grip cable pushdown, close-grip bench press, skull crushers (bar to forehead), reverse-grip dumbbell press, tricep dips, cable concentration extension, and diamond push-ups. Reverse-grip variations are the primary tool for targeting this head specifically.
How many sets should I do for inside tricep exercises?
Keep total tricep training to 10–12 sets per session. Dedicate 3–4 sets to medial head-focused exercises such as reverse-grip pushdowns. Train triceps twice per week with 48–72 hours of recovery between sessions, accounting for any chest or shoulder work that also loads the triceps indirectly.
Why are my inside triceps not growing?
Common reasons include: exclusively using overhand-grip pushdowns (which bias the lateral head), not reaching full lockout on reps, always training heavy with low reps, and insufficient recovery between sessions. Adding reverse-grip movements, extending fully on every rep, and including higher-rep finishers (15–25 reps) will typically restart progress.
