Forearm Exercises for Muscle Growth and Strength: So you've put a lot of strength into your upper body, but how about your grip strength? Unless you're doing forearm workouts, chances are high that your forearms are weak. As such we've rounded up 3 effective exercises to improve grip strength and develop bigger forearms: Warm-up stretching: Start with light stretching as this will prepare your forearms for the exercises. 1. Dumbbell wrist flexion: 2. Dumbbell wrist extension: 3. Pull-up bar hang: