Previous studies have demonstrated that full recovery from weight loss may take months
or years. The present investigation examined short-term recovery (5 wks "post") of
physical performance (muscular strength, muscular power, vertical jump), body composition,
metabolic hormones (testosterone, luteinizing hormone, sex hormone binding globulin,
insulin-like growth factor-1, triiodothyronine, thyroxine, thyroid binding globulin, and thyroid-stimulating hormone)
and metabolic markers (transferrin, ferritin, prealbumin, glycerol, nonesterified
fatty acids, high-density lipoproteins, and lactate) in 10 healthy young men after
an 8-week Army course with an energy deficit (1000 kcal/d) and loss of body mass (-
12 %). Subjects ate ad libitum after the course ended ("post"). Body composition was
determined by dual-energy X-ray absorptiometry; strength from a simulated power clean,
power from body mass and jump height, and metabolic hormones were measured in morning-fasted
blood by radioimmunoassay. With the exception of transferrin and glycerol, all study
parameters were significantly (p<.05) altered by the training course. At 5 weeks post
fat-free mass along with all physical performance measures returned to initial levels;
however, fat mass had significantly (p<.05) increased over initial levels. Also, with
the exception of lactate, all measured hormones and markers were close to initial
levels and within normal ranges. Reported complications during recovery included sleep
irregularities, diarrhea, loss of motivation and feelings of fatigue. While the long
range effect of this energy deprivation experience is uncertain, these data do suggest
that severe weight loss does not result in lasting alterations of the contractile
and metabolic properties of skeletal muscle in young, lean, healthy men.
Key words
Weight loss - hormonal adaptations - catabolism - body composition - military personnel
