|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SKELETAL MUSCLE AND EXERCISE |
1 Institute of Sports Medicine Copenhagen, University of Copenhagen, Copenhagen, Denmark
2 Institute of Sports Sciences and Clinical Biomechanics, University of Southern Denmark, Odeuse, Denmark
3 Department of Physical Education and Health, Örebro University, 70182, Orebro, Sweden
The present study investigated the influence of creatine and protein supplementation on satellite cell frequency and number of myonuclei in human skeletal muscle during 16 weeks of heavy-resistance training. In a double-blinded design 32 healthy, male subjects (1926 years) were assigned to strength training (STR) while receiving a timed intake of creatine (STR-CRE) (n = 9), protein (STR-PRO) (n = 8) or placebo (STR-CON) (n = 8), or serving as a non-training control group (CON) (n = 7). Supplementation was given daily (STR-CRE: 624 g creatine monohydrate, STR-PRO: 20 g protein, STR-CON: placebo). Furthermore, timed protein/placebo intake were administered at all training sessions. Muscle biopsies were obtained at week 0, 4, 8 (week 8 not CON) and 16 of resistance training (3 days per week). Satellite cells were identified by immunohistochemistry. Muscle mean fibre (MFA) area was determined after histochemical analysis. All training regimes were found to increase the proportion of satellite cells, but significantly greater enhancements were observed with creatine supplementation at week 4 (compared to STR-CON) and at week 8 (compared to STR-PRO and STR-CON) (P < 0.010.05). At week 16, satellite cell number was no longer elevated in STR-CRE, while it remained elevated in STR-PRO and STR-CON. Furthermore, creatine supplementation resulted in an increased number of myonuclei per fibre and increases of 1417% in MFA at week 4, 8 and 16 (P < 0.01). In contrast, STR-PRO showed increase in MFA only in the later (16 week, +8%) and STR-CON only in the early (week 4, +14%) phases of training, respectively (P < 0.05). In STR-CRE a positive relationship was found between the percentage increases in MFA and myonuclei from baseline to week 16, respectively (r = 0.67, P < 0.05). No changes were observed in the control group (CON). In conclusion, the present study demonstrates for the first time that creatine supplementation in combination with strength training amplifies the training-induced increase in satellite cell number and myonuclei concentration in human skeletal muscle fibres, thereby allowing an enhanced muscle fibre growth in response to strength training.
(Received 10 February 2006;
accepted after revision 30 March 2006;
first published online 31 March 2006)
Corresponding author P. Aagaard: Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, Build. 8, 1. floor, DK-2400 Copenhagen NV, Denmark. Email: p.aagaard{at}mfi.ku.dk
This article has been cited by other articles:
![]() |
R. S. O'Connor, C. M. Steeds, R. W. Wiseman, and G. K. Pavlath Phosphocreatine as an energy source for actin cytoskeletal rearrangements during myoblast fusion J. Physiol., June 15, 2008; 586(12): 2841 - 2853. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Deldicque, P. Atherton, R. Patel, D. Theisen, H. Nielens, M. J. Rennie, and M. Francaux Effects of resistance exercise with and without creatine supplementation on gene expression and cell signaling in human skeletal muscle J Appl Physiol, February 1, 2008; 104(2): 371 - 378. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Safdar, N. J. Yardley, R. Snow, S. Melov, and M. A. Tarnopolsky Global and targeted gene expression and protein content in skeletal muscle of young men following short-term creatine monohydrate supplementation Physiol Genomics, January 17, 2008; 32(2): 219 - 228. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Deldicque, D. Theisen, L. Bertrand, P. Hespel, L. Hue, and M. Francaux Creatine enhances differentiation of myogenic C2C12 cells by activating both p38 and Akt/PKB pathways Am J Physiol Cell Physiol, October 1, 2007; 293(4): C1263 - C1271. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. L. Mackey, M. Kjaer, S. Dandanell, K. H. Mikkelsen, L. Holm, S. Dossing, F. Kadi, S. O. Koskinen, C. H. Jensen, H. D. Schroder, et al. The influence of anti-inflammatory medication on exercise-induced myogenic precursor cell responses in humans J Appl Physiol, August 1, 2007; 103(2): 425 - 431. [Abstract] [Full Text] [PDF] |
||||
![]() |
Corrigenda J. Physiol., September 15, 2006; 575(3): 971 - 971. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |