TY - JOUR
T1 - Age-related myofiber atrophy in old mice is reversed by ten weeks voluntary high-resistance wheel running
AU - Olesen, Annesofie Thorup
AU - Alchow-Moller, Lasse
AU - Bendixen, Rune Duus
AU - Kjaer, Michael
AU - Svensson, Rene Bruggebusch
AU - Andersen, Jesper Lovind
AU - Magnusson, S. Peter
PY - 2021
Y1 - 2021
N2 - Objective
Age-related loss of muscle mass and function can be attenuated in rodents with life-long voluntary wheel running with moderate resistance. The present study assessed if sarcopenia could be counteracted with ten weeks high intensity training.
Method
Old (22–23 months) and middle-aged (11 months) mice were divided into three physical activity groups: Ten weeks of voluntary running in wheels with high (HR) or low resistance (LR), or no running wheel (SED). The wheel resistance was 0.5–1.5 g in the LR group and progressed from 5 g to 10 g in the HR group. Six, 8 and 5 old and 8, 9 and 9 middle-aged mice of the SED, LR and HR groups, respectively, were included in the analysis. Wheel activity was monitored throughout the intervention. Muscle mass of the tibialis anterior, gastrocnemius, soleus and plantaris muscles were measured post-mortem. Fiber type distribution and myofiber cross sectional areal (CSA) were quantified in the gastrocnemius and soleus muscles as well as total number of fibers in the soleus muscle.
Results
In the SED, the mass of all individual muscles was reduced in the old vs middle-aged (P < 0.001). In the training groups, the old mice ran significantly less, slower and for shorter bouts than the middle-aged throughout the intervention (P < 0.05). HR running increased the gastrocnemius and soleus muscle mass by 6% and 18% respectively in the old compared to SED. Fiber CSA was significantly reduced in the old SED mice, whereas fiber CSA in the old HR gastrocnemius and soleus muscles was comparable to the SED middle-aged. Fiber type shifted from 2b towards 2a in the gastrocnemius muscle of the trained old mice. HR running was more efficient than LR in maintaining muscle mass and myofiber size, and in shifting fiber types. In the middle-aged mice, similar effects were found, but less pronounced. Interestingly, fiber CSA was unaffected by running in the middle-aged.
Conclusion
Ten weeks of HR running had a positive effect on muscle mass and morphology in both middle-aged and old mice. The old HR fiber CSA was greater than in old SED and comparable to the middle-aged, and the fibers shifted to a more oxidative composition (2b → 2a). Albeit less pronounced, similar training effects were observed in the middle-aged mice despite running faster and longer than the old.
AB - Objective
Age-related loss of muscle mass and function can be attenuated in rodents with life-long voluntary wheel running with moderate resistance. The present study assessed if sarcopenia could be counteracted with ten weeks high intensity training.
Method
Old (22–23 months) and middle-aged (11 months) mice were divided into three physical activity groups: Ten weeks of voluntary running in wheels with high (HR) or low resistance (LR), or no running wheel (SED). The wheel resistance was 0.5–1.5 g in the LR group and progressed from 5 g to 10 g in the HR group. Six, 8 and 5 old and 8, 9 and 9 middle-aged mice of the SED, LR and HR groups, respectively, were included in the analysis. Wheel activity was monitored throughout the intervention. Muscle mass of the tibialis anterior, gastrocnemius, soleus and plantaris muscles were measured post-mortem. Fiber type distribution and myofiber cross sectional areal (CSA) were quantified in the gastrocnemius and soleus muscles as well as total number of fibers in the soleus muscle.
Results
In the SED, the mass of all individual muscles was reduced in the old vs middle-aged (P < 0.001). In the training groups, the old mice ran significantly less, slower and for shorter bouts than the middle-aged throughout the intervention (P < 0.05). HR running increased the gastrocnemius and soleus muscle mass by 6% and 18% respectively in the old compared to SED. Fiber CSA was significantly reduced in the old SED mice, whereas fiber CSA in the old HR gastrocnemius and soleus muscles was comparable to the SED middle-aged. Fiber type shifted from 2b towards 2a in the gastrocnemius muscle of the trained old mice. HR running was more efficient than LR in maintaining muscle mass and myofiber size, and in shifting fiber types. In the middle-aged mice, similar effects were found, but less pronounced. Interestingly, fiber CSA was unaffected by running in the middle-aged.
Conclusion
Ten weeks of HR running had a positive effect on muscle mass and morphology in both middle-aged and old mice. The old HR fiber CSA was greater than in old SED and comparable to the middle-aged, and the fibers shifted to a more oxidative composition (2b → 2a). Albeit less pronounced, similar training effects were observed in the middle-aged mice despite running faster and longer than the old.
KW - Training
KW - Exercise
KW - Aging
KW - Skeletal muscle
KW - Muscle morphology
KW - Mouse model
U2 - 10.1016/j.exger.2020.111150
DO - 10.1016/j.exger.2020.111150
M3 - Journal article
C2 - 33181317
VL - 143
JO - Experimental Gerontology
JF - Experimental Gerontology
SN - 0531-5565
M1 - 111150
ER -