We lose a lot of muscle as we age. This is a big concern for patients and clients.
Here is the breakdown of atrophy over a 50-year period (comparing 25 and 75 year olds):
Elbow extensors (triceps): -20%, -0.39%/yr
Elbow flexors (biceps): -19%, -0.38%/yr
Paraspinals (long back muscles): -24%, -0.47%/yr
Psoas (hip flexor): -29%, -0.58%/yr
Hip adductors (groin): -13%, -0.27%/yr
Hamstrings (back of thigh): -19%, -0.39%/yr
Quadriceps (front of thigh): -27%, -0.53%/yr
Dorsiflexors (front of shin): -9%, -0.19%/yr
Triceps surae (calf): -14%, -0.28%/yr
The rate of atrophy accelerates as we age. Here are the differences in the 50-year average and the final 10 years for the large muscle groups:
Paraspinals: −0.47%/yr vs. −0.79%/yr
Psoas: −0.58%/yr vs. −0.83%/yr
Hamstrings: −0.39%/yr vs. −1.22%/yr
Quadriceps: −0.53%/yr vs. −1.32%/yr).
The other issue was the preferential decline of type II muscle fibers. Your type II fibers are fast twitch and primarily responsible for strength and power. Power is how fast you can produce force, a vital action for preventing falls.
So, how can you minimize or potentially reverse atrophy?