TY - JOUR
T1 - Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage
AU - Damas, F.
AU - Phillips, S.M.
AU - Libardi, C.A.
AU - Vechin, F.C.
AU - Lixandrao, M.E.
AU - Jannig, Paulo Roberto
AU - Costa, L.A.
AU - Bacurau, A.V.
AU - Snijders, Tim
AU - Parise, G.
AU - Tricoli, V.
AU - Roschel, H.
AU - Ugrinowitsch, C.
PY - 2016/9/15
Y1 - 2016/9/15
N2 - Key points Skeletal muscle hypertrophy is one of the main outcomes from resistance training (RT), but how it is modulated throughout training is still unknown. We show that changes in myofibrillar protein synthesis (MyoPS) after an initial resistance exercise (RE) bout in the first week of RT (T1) were greater than those seen post-RE at the third (T2) and tenth week (T3) of RT, with values being similar at T2 and T3. Muscle damage (Z-band streaming) was the highest during post-RE recovery at T1, lower at T2 and minimal at T3. When muscle damage was the highest, so was the integrated MyoPS (at T1), but neither were related to hypertrophy; however, integrated MyoPS at T2 and T3 were correlated with hypertrophy. We conclude that muscle hypertrophy is the result of accumulated intermittent increases in MyoPS mainly after a progressive attenuation of muscle damage.AbstractSkeletal muscle hypertrophy is one of the main outcomes of resistance training (RT), but how hypertrophy is modulated and the mechanisms regulating it are still unknown. To investigate how muscle hypertrophy is modulated through RT, we measured day-to-day integrated myofibrillar protein synthesis (MyoPS) using deuterium oxide and assessed muscle damage at the beginning (T1), at 3weeks (T2) and at 10weeks of RT (T3). Ten young men (27(1)years, mean (SEM)) had muscle biopsies (vastus lateralis) taken to measure integrated MyoPS and muscle damage (Z-band streaming and indirect parameters) before, and 24h and 48h post resistance exercise (post-RE) at T1, T2 and T3. Fibre cross-sectional area (fCSA) was evaluated using biopsies at T1, T2 and T3. Increases in fCSA were observed only at T3 (P=0.017). Changes in MyoPS post-RE at T1, T2 and T3 were greater at T1 (P
AB - Key points Skeletal muscle hypertrophy is one of the main outcomes from resistance training (RT), but how it is modulated throughout training is still unknown. We show that changes in myofibrillar protein synthesis (MyoPS) after an initial resistance exercise (RE) bout in the first week of RT (T1) were greater than those seen post-RE at the third (T2) and tenth week (T3) of RT, with values being similar at T2 and T3. Muscle damage (Z-band streaming) was the highest during post-RE recovery at T1, lower at T2 and minimal at T3. When muscle damage was the highest, so was the integrated MyoPS (at T1), but neither were related to hypertrophy; however, integrated MyoPS at T2 and T3 were correlated with hypertrophy. We conclude that muscle hypertrophy is the result of accumulated intermittent increases in MyoPS mainly after a progressive attenuation of muscle damage.AbstractSkeletal muscle hypertrophy is one of the main outcomes of resistance training (RT), but how hypertrophy is modulated and the mechanisms regulating it are still unknown. To investigate how muscle hypertrophy is modulated through RT, we measured day-to-day integrated myofibrillar protein synthesis (MyoPS) using deuterium oxide and assessed muscle damage at the beginning (T1), at 3weeks (T2) and at 10weeks of RT (T3). Ten young men (27(1)years, mean (SEM)) had muscle biopsies (vastus lateralis) taken to measure integrated MyoPS and muscle damage (Z-band streaming and indirect parameters) before, and 24h and 48h post resistance exercise (post-RE) at T1, T2 and T3. Fibre cross-sectional area (fCSA) was evaluated using biopsies at T1, T2 and T3. Increases in fCSA were observed only at T3 (P=0.017). Changes in MyoPS post-RE at T1, T2 and T3 were greater at T1 (P
KW - HUMAN SKELETAL-MUSCLE
KW - MAXIMAL ECCENTRIC EXERCISE
KW - TO-DAY CHANGES
KW - ELBOW FLEXORS
KW - YOUNG MEN
KW - FED STATE
KW - LENGTHENING CONTRACTIONS
KW - SATELLITE CELLS
KW - HUMANS
KW - RESPONSES
U2 - 10.1113/JP272472
DO - 10.1113/JP272472
M3 - Article
C2 - 27219125
SN - 0022-3751
VL - 594
SP - 5209
EP - 5222
JO - Journal of Physiology
JF - Journal of Physiology
IS - 18
ER -