An isometric contraction is when your muscles contract and stay contracted over time. You isometrically contract your muscles throughout the day. When you sit, your abdominals and lower back isometrically contract to hold your torso steady. Holding a bag of groceries in your arms forces your biceps to contract isometrically. The major muscles in your arms include your deltoids, or shoulders, your biceps brachii and your triceps brachii. You can target each with isometric exercises. Hold each position for 20 to 30 seconds.
Isometric Close Grip Pushup
Isometric close grip pushups target both your shoulders and triceps. Get into a traditional pushup position except with your hands set to a narrow position so that they’re placed directly under your shoulders. Bend your elbows and keep them close to your sides as your body lowers down to the floor. Continue down until your upper arms are in line with your torso and then hold yourself in this position. If you struggle at this exercise, start by completing it with your knees placed on the floor instead of being up onto your toes.
Dumbbell Isometric Lateral Raise
The dumbbell isometric lateral raise isolates your shoulders. To perform the isometric lateral raise, hold a pair of dumbbells in each hand with your arms hanging down in front of you, palms facing your thighs. Keep your arms straight as you lift the weights up until your arms are parallel with the floor and hold this position.
Dumbbell Isometric Biceps Curls
Isometric biceps curls target the biceps brachii at the front of your upper arms. Hold a pair of dumbbells in each hand with your arms down by your sides, palms facing forward. Keep your elbows into your side and bend them until your forearms are parallel with the floor. Hold your elbows in this position. You can also complete this exercise one arm at a time. While you’re holding one elbow at 90 degrees, perform full repetitions of biceps curl with the opposite arm.
To isometrically challenge your shoulders and triceps brachii muscle, perform the L-sit. Sit upright on a mat with your legs extended out in front of you. Place your palms down on the floor by your hips, rise up onto your hands and push your hips up off the floor. Hold this position.
Dumbbell Isometric Overhead Triceps Extension
The isometric overhead triceps extension with dumbbells isolates your triceps. Grip a single dumbbell with both hands. Hold the weight over your head with arms extended. Bend your elbows to lower the weight behind your head. Stop once your elbows are bent to 90 degrees and hold this position.
Kim Nunley has been screenwriting and working as an online health and fitness writer since 2005. She’s had multiple short screenplays produced and her feature scripts have placed at the Austin Film Festival. Prior to writing full-time, she worked as a strength coach, athletic coach and college instructor. She holds a master's degree in kinesiology from California State University, Fullerton.