How to jm press on chest press machine
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Last updated: April 4, 2026
Key Facts
- The JM press is a hybrid exercise combining elements of the close-grip bench press and the overhead triceps extension.
- It effectively targets the pectoralis major (chest), anterior deltoids (front shoulders), and triceps.
- Proper form involves maintaining control throughout the movement and avoiding momentum.
- The machine variation allows for a more stable and controlled range of motion compared to free weights.
- Starting with a lighter weight is recommended to master the technique before increasing the load.
Overview
The JM press is a unique and effective exercise often performed with dumbbells or barbells, but it can also be adapted for a chest press machine. This compound movement is highly regarded for its ability to build mass and strength in the upper body, specifically targeting the chest, shoulders, and triceps. By integrating elements of both a pressing motion and an extension, it provides a comprehensive stimulus to these muscle groups. Using a chest press machine offers an advantage by providing stability, allowing the user to focus more on muscle activation and less on balance, which can be particularly beneficial for beginners or those looking to isolate specific muscle groups.
Understanding the JM Press
The JM press is named after its creator, Jim Morris, a legendary bodybuilder. It's characterized by a unique arm path where the elbows are kept relatively stationary and close to the body, and the movement involves a combination of shoulder flexion (pressing up) and elbow extension (straightening). Unlike a standard chest press where the arms might move in a wider arc, the JM press brings the bar or handles closer to the upper chest/neck area at the bottom of the movement, emphasizing the triceps and the inner portion of the chest more intensely. The machine variation typically involves handles that move on a fixed path, which can help guide the user through the correct range of motion.
How to Perform the JM Press on a Chest Press Machine
Setting up correctly is crucial for maximizing the benefits and minimizing the risk of injury. Here’s a step-by-step guide:
- Machine Setup: Adjust the seat height so that when you grip the handles, they are roughly in line with the middle of your chest. Ensure the back support is comfortable and provides adequate stability.
- Grip: Position yourself on the seat and grip the handles with an overhand grip. The grip width should be slightly narrower than a standard chest press, typically around shoulder-width or slightly less. This closer grip is key to engaging the triceps more significantly.
- Starting Position: Unrack the weight by fully extending your arms. Your chest should be slightly puffed out, and your shoulder blades should be squeezed together and down.
- The Descent: Slowly lower the handles towards your upper chest or the base of your neck. Keep your elbows tucked in close to your body throughout the movement. Avoid flaring your elbows out wide, as this shifts the emphasis away from the triceps and chest towards the shoulders and can increase injury risk. The movement should feel controlled, and you should feel a stretch in your chest and triceps.
- The Press: Once you’ve reached the bottom of the range of motion (without letting the weight touch your body or losing tension), press the handles back up to the starting position. Focus on driving through your palms, squeezing your chest muscles at the top of the movement. Keep your elbows relatively tucked as you extend your arms.
- Breathing: Inhale as you lower the weight and exhale as you press it back up.
- Repetitions: Complete your desired number of repetitions, maintaining strict form throughout.
Benefits of the Machine JM Press
The chest press machine offers several advantages for performing the JM press:
- Stability: The fixed path of the machine provides a stable platform, allowing for greater focus on muscle contraction without worrying about balancing the weight.
- Controlled Range of Motion: The machine guides the movement, which can help users learn the proper form and ensure a consistent range of motion throughout each repetition.
- Reduced Risk of Injury: For individuals with shoulder issues or those new to the exercise, the machine can offer a safer alternative to free weights, as it limits excessive joint stress when used correctly.
- Muscle Isolation: By minimizing the need for stabilization, the machine can help to better isolate the chest and triceps muscles.
Tips for an Effective JM Press on the Machine
- Mind-Muscle Connection: Focus intensely on squeezing your chest and triceps throughout the entire range of motion. Imagine you are trying to bring your elbows together as you press up.
- Control the Eccentric: Pay special attention to the lowering (eccentric) phase of the lift. A slow, controlled descent (2-3 seconds) will increase time under tension and stimulate more muscle growth.
- Elbow Position: Keep your elbows tucked in close to your body. This is paramount for targeting the triceps and upper chest effectively and safely.
- Grip Width: Experiment with grip width, but generally, a slightly narrower grip than a standard chest press is recommended.
- Full Range of Motion: Aim for a deep stretch at the bottom without compromising form or comfort, and a full extension at the top, but avoid locking out the elbows forcefully.
- Progressive Overload: Gradually increase the weight, repetitions, or sets over time to continue challenging your muscles and promoting growth.
- Listen to Your Body: If you experience any pain, especially in your shoulders or elbows, stop the exercise and reassess your form or reduce the weight.
Common Mistakes to Avoid
When performing the JM press on a chest press machine, be aware of these common errors:
- Flaring Elbows: Allowing the elbows to drift wide is the most common mistake and significantly reduces the effectiveness for triceps and chest, while increasing shoulder strain.
- Using Momentum: Bouncing the weight off the chest or using excessive body English defeats the purpose of the exercise and increases injury risk.
- Too Wide Grip: A grip that is too wide will shift the emphasis away from the triceps and the intended inner chest activation.
- Incomplete Range of Motion: Not going deep enough or not fully extending at the top limits the stimulus.
- Ignoring the Triceps: Focusing solely on pressing the weight up without actively engaging the triceps will make it less of a JM press and more of a standard chest press.
Conclusion
The JM press on a chest press machine is a valuable addition to any upper body workout routine. By understanding the proper technique, focusing on controlled movements, and maintaining the correct elbow position, you can effectively build strength and muscle in your chest, shoulders, and triceps. Remember to prioritize form over weight and listen to your body to ensure a safe and productive training session.
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