Biceps and triceps are not enough: Fitness trainer urges strengthening these key muscles to stay pain-free and confident with age

For many fitness enthusiasts, strength training revolves around what’s visible in the mirror: chest, arms, quads, and occasionally abs. But according to Marfred Suazo, a New York City trainer known as Fonz the Trainer, this approach leaves the body unbalanced and prone to aches. Speaking with Fox News Digital, Suazo explained, “Most people train what they see in the mirror. That’s what I call ‘mirror training.’ The problem is it can lead to rounded shoulders, tight chests, and sore backs or knees.”

The Case for Non-Mirror Training
Suazo emphasizes the importance of focusing on muscles you can’t see but feel every day. “If you want to age strong, pain-free and confident, you need non-mirror training,” he told Fox News Digital. His personal experience in competitive swimming and martial arts taught him that strengthening the back side of the body improves speed, balance, and resilience.

Key Muscles to Target for Longevity
According to Suazo, the glutes and hamstrings are essential for everyday movement and back protection. Recommended exercises include deadlifts, hip thrusts, and single-leg bridges, performed with controlled motion and deliberate squeezes at the top. A strong back, trained through bent-over rows, cable rows, and bodyweight rows, helps pull shoulders into alignment and improves posture.

Core, Shoulders, and Grip Matter Too
Suazo stresses that a functional core is about stability, not just visible abs. The Paloff press, performed standing or kneeling with a resistance band, strengthens the core to protect the spine during daily activity. Shoulders require mobility and strength through face pulls, rear delt flies, and controlled overhead presses. Grip strength, often overlooked, is vital for independence, with farmer’s carries recommended at 70% of body weight per hand.

These non-mirror muscles complement traditional strength pillars: push, pull, carry, hinge, overhead press, and squat. Suazo advises beginners to start with three sets of 8-10 deadlifts, 3 sets of 10 Paloff presses per side, and three 30-45 second farmer’s carries, finishing with a short walk. “Non-mirror training is how you build a body that lasts — strong, upright, and pain-free,” he said.

While push-ups, curls, and other traditional exercises remain important, Suazo’s message is clear: equal attention to the muscles you don’t see in the mirror transforms not just appearance, but mobility, posture, and overall quality of life.