Premium
Changes in muscle volume and strength following prolonged bed rest
Author(s) -
Heinicke Katja,
Wyrick Phil,
Krainski Felix,
Hastings Jeffrey L.,
Pacini Eric,
Palmer Dean,
Haller Ronald G.,
Levine Benjamin D.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.752.6
Subject(s) - ankle , bed rest , medicine , thigh , rowing , knee flexion , anatomy , plantar flexion , physical medicine and rehabilitation , archaeology , history
PURPOSE To determine the effectiveness of dynamic and resistance exercise training in attenuating the loss of structure and functional capacity of skeletal muscle during bed rest. METHODS: Muscle volume and peak torque (Pk T) were assessed before (Pre) and following 5 weeks of −6° head down tilt bed rest in 5 (exercise) and 3 (sedentary group) healthy subjects. Training consisted of rowing (6x/wk) and resistance (2x/wk) training. The sedentary group did no training. Each subject underwent MRI (1.5T) quantification of segmental volumes of 15 contiguous 0.6 cm thick transaxial images of calf and thigh muscles. Peak isokinetic torque during ankle plantar/dorsiflexion and knee extension/flexion was determined. Correlation coefficients for muscle volume and Pk T were determined for leg anti‐gravity muscles. RESULTS: Calf muscle volume decreased slightly by 4% while Pk T increased 31% Pre to Post in the exercise group. In sedentary corresponding values were −15% and −20%. Thigh muscle volume decreased 4% while Pk T decreased 5% Pre to Post in the exercise group. In sedentary corresponding values were −7% and −10%. CONCLUSION: The loss of calf and thigh muscle volume was attenuated but could not be completely eliminated by exercise training during 5 weeks of bed rest. However, muscle function was well preserved with no clinically relevant loss of strength in anti‐gravity muscles. Supported by NASA grant CA00701.