When it comes to how your body ages, strength plays a key role, and experts believe one simple habit can make a remarkable difference. While many people see exercise mainly as a way to lose weight or look better, its true impact lies in preserving muscle and energy systems that keep you moving well over time.
Many skip structured workouts, believing that daily activities are enough. But according to fitness specialists, combining targeted training with regular movement can be the single most effective way to protect your body’s function and energy levels over time.
What’s the exercise that can make your body feel 20 years younger?
The answer is strength training combined with daily movement. Felipe Isidro, professor of physical education and CEO of Physical Exercise & Health Consulting, explained that relying only on walking, climbing stairs, or carrying bags isn’t enough to keep the body youthful. While all movement is beneficial, strength work is what keeps muscles, mitochondria, and fast-twitch fibers strong — key components of energy, mobility, and longevity.
Isidro points out that mitochondria act like batteries: when they’re healthy, you feel strong and energized; when they decline, fatigue sets in more easily. Strength training is the only “medicine” proven to maintain their function.
It also preserves fast-twitch fibers, which are responsible for speed and power but naturally decline with age. Without strength work, people often become slower and less stable, which accelerates aging in the body.
He explains that we build muscle up to age 25, maintain it until around 35, and gradually lose it afterward — faster after 50 and even more after 65. However, regular strength training can counteract that decline. Some people in their 70s maintain the strength of sedentary individuals decades younger simply by sticking to a consistent training routine.
How to train the right way at any age
Isidro emphasizes that strength training doesn’t mean endless reps or exhausting sessions. In fact, the key is quality over fatigue. He recommends few repetitions, lots of recovery time, and avoiding exhaustion. When you reach fatigue, you start relying on slow-twitch fibers and losing the fast ones that protect your body’s youthfulness.
Here are some of his essential guidelines:
- Start with two sessions per week, and gradually build up to three or four. Alternate training days with rest.
- Prioritize strength before cardio if doing both on the same day.
- Focus on the legs first. They hold the most muscle mass and are the quickest to decline.
- Train with intensity, not volume. Fewer, faster reps activate fast-twitch fibers through the nervous system.
- Rest between sets for at least one minute — ideally two or three — to fully recover.
- Avoid fatigue by stopping before you’re exhausted.
- Keep sessions short, between 5 and 15 minutes, to make them easy to maintain daily.
- Breathe deeply to strengthen respiratory muscles and improve endurance.
He also highlights that the best time to exercise is in the morning, which helps regulate your nervous system and improves sleep at night. Whenever possible, working out outdoors and with others adds social and emotional benefits that also support healthy aging.
Simple ways to measure progress
You don’t need expensive equipment to check your strength. Isidro suggests a few at-home tests to track improvements over time:
- Chair test: Sit and stand five times quickly using only your legs to measure lower body strength.
- Stork test: Stand on one leg to assess balance and control. Younger people can do it with eyes closed; older adults can keep them open.
- Six-minute endurance test: Walk as fast as possible for six minutes. Distances under 500 meters indicate low fitness, while over 700 meters is excellent.