title: Maximal explosive power of the lower limbs before and after 35 days of bed rest under different diet energy intake.
abstract: OBJECTIVE
  Microgravity leads to a decline of muscle power especially in the postural muscles of the lower limb. Muscle atrophy primarily contributes to this negative adaptation. Nutritional countermeasures during unloading were shown to possibly mitigate the loss of muscle mass and strength. The aim of this study was to investigate the effects of different diet energy intakes during prolonged inactivity on body composition and lower limbs power output.
  
  
  METHODS
  The effects of lower or higher diet energy intake on the decline of maximal explosive power of the lower limbs, as determined on a sledge ergometer before and after 35 days of bed rest, were investigated on two matched groups of young healthy volunteers. Body composition and lean volume of the lower limb were also measured.
  
  
  RESULTS
  After bed rest, fat mass increased (+20.5 %) in the higher energy intake group (N = 9), while it decreased (-4.8 %) in the lower energy intake group (N = 10). Also, the loss of body fat-free mass and lean volume of the lower limb was significantly greater in the higher (-4.6 and -10.8 %, respectively) as compared to the lower (-2.4 and -3.7 %, respectively) diet energy intake group. However, the loss of maximal explosive power was similar between the two groups (-25.2 and -29.5 % in the higher and lower energy intake group, respectively; P = 0.440).
  
  
  CONCLUSIONS
  The mitigation of loss of muscle mass by means of a moderate caloric diet restriction during prolonged inactivity was not sufficient for reducing the loss of maximal explosive power of the lower limbs.
authors.affiliation: Department of Medical and Biological Sciences, University of Udine, P.le Kolbe 4, 33100, Udine, Italy, enrico.rejc@uniud.it.
authors.forename: Enrico
authors.initials: E
authors.lastname: Rejc
authors.forename: Pietro Enrico
authors.initials: PE
authors.lastname: di Prampero
authors.forename: Stefano
authors.initials: S
authors.lastname: Lazzer
authors.forename: Bruno
authors.initials: B
authors.lastname: Grassi
authors.forename: Bostjan
authors.initials: B
authors.lastname: Simunic
authors.forename: Rado
authors.initials: R
authors.lastname: Pisot
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Antonutto
authors.forename: Marco
authors.initials: M
authors.lastname: Narici
mesh_terms: D000328:Adult; D001510:Bed Rest / Q000009:adverse effects*; D016022:Case-Control Studies; D004032:Diet; D002149:Energy Intake; D016552:Ergometry; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology; D014893:Weightlessness / Q000009:adverse effects*