TY - JOUR
T1 - Improvements in whole muscle and myocellular function are limited with high-intensity resistance training in octogenarian women
AU - Raue, Ulrika
AU - Slivka, Dustin
AU - Minchev, Kiril
AU - Trappe, Scott
PY - 2009/5
Y1 - 2009/5
N2 - Advanced sarcopenia is prevalent among octogenarian women; yet little is known about myocellular quality and plasticity in this cohort. The aim of this investigation was to examine single muscle fiber contractile function and whole muscle characteristics before and after 12 wk of high-intensity progressive resistance training (PRT) in very old (85 ± 1 yr) women (OW, n = 6). Young women [YW (21 ± 2 yr old), n = 9] were included as a control group. Whole muscle strength [1 repetition maximum (RM)] and size (CT scans) were assessed before and after PRT. Functional experiments (size, peak force, velocity, and power) were performed on vastus lateralis myosin heavy chain (MHC) I and IIa muscle fibers before and after PRT. With PRT, 1-RM strength increased (P < 0.05) in YW (36%) and OW (26%). Thigh muscle cross-sectional area increased (5%) in YW (P < 0.05), but thigh muscle did not hypertrophy in OW. Before PRT, there were no differences in single-fiber parameters between YW and OW. With PRT, MHC IIa fiber size (28%), peak force (31%), and power (28%) improved, but no changes were observed in MHC I fibers, in YW (P < 0.05). There were no improvements in MHC I or IIa single-fiber function in OW. These data show that the myocellular functional profile in OW is similar to that in YW but that OW have a blunted hypertrophic response to PRT at the whole muscle and myocellular level. The limited myocellular plasticity in OW with PRT contrasts with that in YW and previous PRT studies in elderly women only a decade younger. These data suggest that attempts to greatly enhance skeletal muscle mass and function should begin before 80 yr of age.
AB - Advanced sarcopenia is prevalent among octogenarian women; yet little is known about myocellular quality and plasticity in this cohort. The aim of this investigation was to examine single muscle fiber contractile function and whole muscle characteristics before and after 12 wk of high-intensity progressive resistance training (PRT) in very old (85 ± 1 yr) women (OW, n = 6). Young women [YW (21 ± 2 yr old), n = 9] were included as a control group. Whole muscle strength [1 repetition maximum (RM)] and size (CT scans) were assessed before and after PRT. Functional experiments (size, peak force, velocity, and power) were performed on vastus lateralis myosin heavy chain (MHC) I and IIa muscle fibers before and after PRT. With PRT, 1-RM strength increased (P < 0.05) in YW (36%) and OW (26%). Thigh muscle cross-sectional area increased (5%) in YW (P < 0.05), but thigh muscle did not hypertrophy in OW. Before PRT, there were no differences in single-fiber parameters between YW and OW. With PRT, MHC IIa fiber size (28%), peak force (31%), and power (28%) improved, but no changes were observed in MHC I fibers, in YW (P < 0.05). There were no improvements in MHC I or IIa single-fiber function in OW. These data show that the myocellular functional profile in OW is similar to that in YW but that OW have a blunted hypertrophic response to PRT at the whole muscle and myocellular level. The limited myocellular plasticity in OW with PRT contrasts with that in YW and previous PRT studies in elderly women only a decade younger. These data suggest that attempts to greatly enhance skeletal muscle mass and function should begin before 80 yr of age.
KW - Aging
KW - Exercise
KW - Single-fiber physiology
KW - Skeletal muscle
UR - http://www.scopus.com/inward/record.url?scp=66349120519&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.91587.2008
DO - 10.1152/japplphysiol.91587.2008
M3 - Article
C2 - 19246651
AN - SCOPUS:66349120519
SN - 8750-7587
VL - 106
SP - 1611
EP - 1617
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 5
ER -