Protein and Strength: What Matters as We Age

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Why researchers start with strength

The European sarcopenia consensus puts low muscle strength at the center of assessment. Grip strength and a timed chair stand are two ways clinicians can assess it. They measure what muscles can do.

What protein added during training

A review of 49 trials involving 1,863 healthy adults found that extra protein during resistance training was associated with about 0.30 kilograms more fat-free mass on average. The review also found a small additional gain in one-repetition maximum strength. The trials varied in duration, age and training experience.

What a scale cannot tell you

Fat-free mass includes tissues other than muscle. A chair stand tests a movement someone needs for ordinary life. These studies illustrate why researchers measure body composition, strength and physical performance separately.

Ten weeks in a nursing home

Fiatarone and colleagues enrolled 100 very old residents. Measured strength rose by 113% with resistance exercise and by 3% among those who did not exercise. The nutritional supplement in that trial did not improve its main outcomes.

Four hundred meters

In the randomized LIFE trial, 30.1% of older adults assigned to a physical activity program developed major mobility disability, compared with 35.5% assigned to health education. The study measured whether participants could walk 400 meters. The program combined walking, resistance, balance, and flexibility work.

References

• Fiatarone et al., NEJM, 1994. Exercise and nutritional supplementation in very elderly people
• Pahor et al., JAMA, 2014. The LIFE randomized trial
• Cruz-Jentoft et al., Age and Ageing, 2019. European sarcopenia consensus
• Morton et al., BJSM, 2018. Protein supplementation during resistance training
• HealthBrew guide to protein and strength training after 60