Reduced type II muscle fiber

Physiological

Data Availability

Period at which this change occurs is not accurately known

Tissue

  • skeletal muscle Changes

References

Referencing provided by LibAge

External Links

Description

Limb muscles from older men and women are 25-35% smaller and have significantly more fat and connective tissue than limb muscles from younger individuals. Quadriceps cross-sectional area is substantially smaller in healthy older versus young men. Type II (fast-twitch) muscle fiber size is substantially smaller in the elderly versus the young, while the size of type I (slow-twitch) fibers is much less affected by age. Differences in type II muscle fiber size fully explained differences in quadriceps cross-sectional area between the two groups. Reduced muscle mass with aging is mainly attributed to smaller type II muscle fiber size.

Relationships