Age-related muscle atrophy does not affect all muscles and can partly be compensated by physical activity: an ultrasound study.

In adults, the volume of quadriceps femoris muscle decreases with age, whereas the impact of increasing age on the size of other extremity muscles was hardly studied. This study was conducted to examine whether age-related muscle atrophy is a general phenomenon, whether it is accompanied by increasing subcutaneous fat and whether physical activity can compensate age-related muscle atrophy. One hundred and two female and 101 male subjects (aged 19-86 years), with common physical activity, as well as 29 women and 38 men (aged 20-81 years) regularly performing sports at least 3 h per week for several years (mean, 10 years in women and 14 years in men, respectively), were examined. Both in athletes and control subjects, the thickness of thigh muscles significantly decreased with age (-15(-)-21% from age 20 to age 70), whereas diameter of upper arm muscles remained nearly unchanged. Diameters of the calf muscle decreased with advancing age only in the control group. In male control subjects, the tibialis anterior muscle shrunk as well. Except for the vastus lateralis muscle in women, the relative loss of muscle thickness was more evident in control subjects than in athletes. Thickness of the subcutaneous fat layers remained almost unchanged. In summary, not all extremity muscles exhibit age-related decrease in size. Regular physical activity can ease off muscle atrophy.