Why Power is More Important Than Strength as We Age

Conversations about health often revolve around maintaining muscle strength, and while this is excellent advice, it only tells part of the story. Recent research highlights a different, more crucial factor for maintaining physical function and independence as we age: muscle power.

As an Exercise Physiologist at Harrison, I guide clients toward healthier, more active lives. A common misconception I encounter is the interchangeability of the terms ‘strength’ and ‘power’. While related, they are not the same.

What is the Difference Between Muscle Strength and Power?

To understand why power is so critical, we first need to define our terms.

Muscle strength is the maximum force a muscle can produce (Force = Mass x Acceleration). Think of it as the heaviest weight you can possibly lift one time. It’s a measure of pure force, typically performed slowly and with control.

Muscle power, on the other hand, is the ability to generate force quickly. The simple formula is Power = Force x Velocity; velocity being directional speed. It’s about how fast you can apply strength and move with intent. Activities like getting up from a chair without using your hands, catching yourself from a stumble, climbing stairs, or lifting a grocery bag off the floor all require power.

While having a good foundation of strength is necessary, it is the speed component of power that becomes a better predictor of our ability to perform daily tasks and maintain independence as we age.

Studies continue to arise and consistently show that muscle power is a more accurate determinant of physical functioning in older adults than muscle strength alone.

When we lose power, simple tasks become more difficult. This often leads to a more sedentary life, accelerating the decline of both strength and power, creating a difficult cycle to break. Maintaining muscle power is therefore crucial for an active, engaged, and independent life.

The Rapid Decline of Muscle Power

It can be a natural part of the aging process to lose muscle mass and function, a condition known as sarcopenia. However, research shows that muscle power declines far more rapidly and starts earlier than muscle strength. This decline has significant consequences for our daily lives.

The physiological reasons for this decline are complex. As we age, our neuromuscular system undergoes significant changes. Our body becomes less efficient at recruiting the muscle fibres needed for quick, explosive movements leaving us more vulnerable to falls, injuries, and other hazards. Specifically, we experience a reduction in Type IIx muscle fibres—our anerobic ‘fast-twitch’ fibres responsible for generating rapid bursts of force.

While “explosive” and “fast-twitch” might sound like terms reserved for athletes, they are essential for everyone. These fibres allow us to react to life’s unexpected challenges, like recovering balance after stepping on an uneven surface or dodging a fast-moving pet darting underfoot. Without the right kind of physical stimulus, we not only lose these fibres, but also the motor units (the nerves that activate them). By the time we reach 70, we may have 40% fewer motor units than we did in our youth, which can significantly impact our ability to stay safe, mobile, and independent as we age.

How to Train for Power

The good news is that this decline is not inevitable. Just as we can train for strength, we can also train for power. The key is to incorporate speed into your resistance exercises. This doesn’t mean you need to start an intense, high-impact workout routine. Power training can be safe, effective, and easily adapted for all fitness levels.

Here are some practical ways to build muscle power:

1. Focus on the Speed of Movement

When performing resistance exercises, concentrate on the “lifting” or “pushing” phase of the movement (the concentric contraction). The goal is to perform this part of the exercise as quickly as you can while maintaining good form and control. The “lowering” phase (eccentric contraction) can be done at a slower, more controlled pace.

2. Incorporate Functional Power Movements

You can integrate power training directly into your daily routine with functional exercises.

• Chair Stands: Sit on a sturdy chair without arms. Stand up as quickly as possible without using your hands for support. Sit back down slowly and with control. Add weight for more resistance.
• Step-Ups: Using an appropriately high, stable step or the bottom stair, step up quickly with one foot, bringing the other to meet it. Step back down slowly, one foot at a time. Add weight for greater resistance.

3. Use Lighter Weights with More Speed

You don’t need to lift extremely heavy weights to build power. In fact, using lighter weights or resistance bands can allow you to focus on the speed of the movement more effectively and safely. Research on high-velocity resistance training has shown it to be highly effective for improving functional performance and even quality of life in older adults. When prescribing velocity for power production, I like to aim for greater than 1.0m per second.

4. Stay Consistent

As with any form of exercise, consistency is key. Aim to incorporate power-focused exercises into your routine one to two times per week. Always listen to your body and consult with a healthcare professional or a qualified Exercise Physiologist before starting a new exercise program, especially if you have pre-existing health conditions.

Your Next Step Towards a Powerful Future

By prioritizing power training as part of your fitness routine, you can unlock new levels of strength, agility, and confidence. With proper guidance and dedication, these exercises can help you maintain an active, independent lifestyle and achieve your long-term health goals.