Quadriceps maximal power and optimal shortening velocity in 335 men aged 23-88 years.
Level 4 - case-series / case-control
Cross-sectional observational study.
PubMed 16032419 · doi:10.1007/s00421-005-1390-8
What was done
Researchers evaluated the relationship between age, quadriceps maximal short-term power (P_max), and optimal shortening velocity (v_opt) in 335 healthy men aged 23 to 88 years. Power and shortening velocity were measured using a friction-loaded non-isokinetic cycle ergometer. Anthropometric measurements were used to estimate lean thigh volume and quadriceps mass.
What was found
Quadriceps maximal power declined across the adult lifespan by 10.7% per decade, beginning after the fourth decade. This decline was driven by both estimated muscle mass reduction (4.1% decline per decade for lean thigh volume; 3.4% per decade for quadriceps mass) and shortening velocity reduction (6.6% decline per decade, starting in the thirties). Age contributed to power variability independently of muscle mass and velocity.
Why it matters
This study shows that age-related power loss outpaces muscle mass decline and starts relatively early in life, largely due to reduced shortening velocity. It suggests functional exercise interventions should emphasize contraction speed alongside muscle hypertrophy.
Limits
The cross-sectional design cannot confirm individual longitudinal trajectories and may be subject to cohort effects. Muscle mass was estimated from anthropometric dimensions rather than direct imaging (e.g., MRI or CT), and the study included only healthy men, limiting generalizability to women or less healthy populations.
Cited by
- supports Muscle power starts declining earlier and declines more rapidly with age than muscle mass or muscle strength.