The Nuance of Strength Training: What Really Contributes to Healthy Aging? by Sander Smets

In recent years, we’ve heard everywhere that strength training is the key to healthy aging. And while strength training is certainly an essential component, that statement deserves more nuance. As a movement expert, I see every day that strength training alone is not enough to remain strong, stable, and self-reliant as we age.

Both scientific research and practical experience point to the same conclusion: healthy aging requires a broader, more functional approach.

The All-Round Human: Why Strength Training Is Only One Pillar

In the book STOP de klok by Ellen Crabbe, this is described beautifully: to build a truly resilient and healthy body, three domains are essential:

• strength training
• cardiovascular training (both endurance and high-intensity)
• stability & balance

Strength training—especially when combined with adequate protein intake—certainly helps slow muscle loss. But independence and balance depend on far more than muscle mass alone. If we want to keep moving the way we do today, a holistic approach is essential.

Single-Joint vs. Multi-Joint: How Functional Do You Want to Train?

Within strength training, we can broadly distinguish between two types of movements:

Single-joint (SJ)
Movement around one joint.
Example: leg extension (knee extension).

Multi-joint (MJ)
Movement around multiple joints.
Example: the squat (ankle, knee, and hip action).

Both types of exercises load the muscles, and both can build muscle mass and strength. Research even shows that hypertrophic effects can be comparable. However, MJ movements offer additional benefits:

• they improve functional strength needed in daily life
• they have a greater positive impact on VO₂ max
• they train muscles to work together—as the body is designed to move

With MJ exercises, you often kill two birds with one stone: you work on strength and cardiovascular capacity.

That said, SJ exercises remain valuable. They help target weak links, which is important for injury prevention and for refining MJ movements. The best approach? A combination, tailored to your individual needs.

Machines vs. Free Exercises: Stability Is Key

In most gyms, machines dominate—and they certainly serve a purpose:

• they provide a safe, controlled movement path
• they are ideal for learning movements and building load tolerance
• both SJ and MJ exercises can be performed on them

However, there is one crucial difference compared to free (or “unassisted”) exercises: stability.

Machines largely take care of stabilization for you. With free exercises, you must constantly correct and control your movement yourself.

And it is precisely this cooperation between large muscle groups and stabilizers that we rely on every day to:

• stay upright
• move smoothly
• reduce the risk of falls
• keep joints healthy

That’s why a mix of machines and free exercises is often the best choice—but training exclusively on machines means missing out on certain functional benefits.

My Plea: Train Smart, Not Just Hard

Imagine you sign up for a gym membership next week. Chances are you’ll start on machines—and that’s perfectly fine. They’re ideal for safely learning basic movements. But as soon as possible, build toward a combination of:

• MJ exercises as your foundation
• SJ exercises to address weaknesses
• free exercises for stability and coordination
• cardio and balance work for the bigger picture

Above all: technique before weight.

No matter which exercise you do—SJ, MJ, machine-based, or free—proper execution makes the difference between progress and injury. And injuries are one of the main reasons people stop exercising altogether.

Not sure whether your movements are correct? Seek guidance from a professional. It can genuinely determine how well you’re moving 20 years from now.

Sources

Schoenfeld, B. J., et al. (2023). Hypertrophic Effects of Single-Versus Multi-Joint Exercise.

Ribeiro, A. S., et al. (2017). Resistance Training with Single vs. Multi-joint
Exercises.

Grgic, J., et al. (2023). Multi-joint vs. Single-joint Resistance Exercises.

Souto Maior, A., & de Assis, M. L. M. (2023). Neuromuscular and Functional
Responses: Free Weights vs. Machines.