Coach Justin Lambert's 40-Rep Bicep Finisher
A fitness coach shares a dumbbell finisher that combines curls and isometric holds for a challenging arm pump, requiring only light weights.
Fitness coach Justin Lambert has designed a dumbbell workout intended to deliver a significant bicep pump. The finisher combines bicep curls, hammer curls, and isometric holds over 40 total reps.
According to a report from Men's Health UK, Lambert states the routine is deceptively challenging. He suggests leaving your ego at the door when selecting dumbbell weight for this burner. "If you want to blow up your arms, this is a bicep burner that you can do once you leave the gym," Lambert says. "The arms are going to feel like they're going to explode."
The Workout Structure
The finisher is a structured sequence of 40 repetitions. One arm performs the curling motion while the other arm holds a dumbbell in a fixed, mid-curl position. This isometric hold maintains constant tension.
The complete set follows this specific order:
| Exercise | Arm |
|---|---|
| 5 Bicep Curls | Right arm |
| 5 Bicep Curls | Left arm |
| 5 Hammer Curls | Right arm |
| 5 Hammer Curls | Left arm |
| 5 Bicep Curls | Right arm |
| 5 Bicep Curls | Left arm |
| 5 Hammer Curls | Right arm |
| 5 Hammer Curls | Left arm |
This pattern ensures neither arm gets a full rest during the set. The non-working muscle remains under tension throughout the entire finisher.
Exercise Execution
Proper form is critical for the intended effect and to avoid using momentum. The source provides specific instructions for each movement.
For the dumbbell bicep curl, stand tall with palms facing forward. Hold one dumbbell with the elbow bent at roughly 90 degrees. With the opposite elbow tucked close to your side, curl that dumbbell toward your shoulder. Squeeze the bicep at the top before lowering the weight under control.
The hammer curl variation changes the grip. Hold the dumbbells with your palms facing each other. Again, keep one arm fixed with the elbow bent to about 90 degrees. Curl the opposite dumbbell toward your shoulder while keeping the elbow tucked in. Lower it under control without swinging your torso.
The Isometric Advantage
The defining feature of this finisher is the continuous isometric tension. While one arm completes its five reps, the other is not resting. It is actively holding a weight in a partially contracted position.
This method increases time under tension for the biceps muscle group. The source indicates this can make lighter dumbbells feel significantly heavier by the end of the set. The goal is muscular fatigue and a pronounced pump, not lifting maximum weight.
The workout is presented as an efficient option to conclude an upper-body training session. Fitness writer Kate, who contributed the report for Men's Health UK, notes the routine requires only a pair of dumbbells. She has a postgraduate diploma in Sports Performance Nutrition and previously worked as a personal trainer.
