| Full text | |
| Author(s): |
Damas, Felipe
[1]
;
Phillips, Stuart M.
[2]
;
Lixandrao, Manoel E.
[1]
;
Vechin, Felipe C.
[1]
;
Libardi, Cleiton A.
[3]
;
Roschel, Hamilton
[1]
;
Tricoli, Valmor
[1]
;
Ugrinowitsch, Carlos
[1]
Total Authors: 8
|
| Affiliation: | [1] Univ Sao Paulo, Sch Phys Educ & Sport, BR-05508030 Sao Paulo, SP - Brazil
[2] McMaster Univ, Dept Kinesiol, Hamilton, ON L8S 4K1 - Canada
[3] Univ Fed Sao Carlos, Lab Neuromuscular Adaptat Resistance Training, BR-13565905 Sao Paulo, SP - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY; v. 116, n. 1, p. 49-56, JAN 2016. |
| Web of Science Citations: | 49 |
| Abstract | |
It has been proposed that skeletal muscle shows signs of resistance training (RT)-induced muscle hypertrophy much earlier (i.e., similar to 3-4 weeks of RT) than previously thought. We determined if early increases in whole muscle cross-sectional area (CSA) during a period of RT were concomitant with edematous muscle swelling and thus not completely attributable to hypertrophy. We analyzed vastus lateralis muscle ultrasound CSA images and their respective echo intensities (CSA-USecho) at the beginning (T1), in the 3rd week of RT (T2) and at the end (T3) of a 10-week RT period in ten untrained young men. Functional parameters {[}training volume (TV = load x reps x sets) and maximal voluntary contraction (MVC)] and muscle damage markers (myoglobin and interleukin-6) were also assessed. Muscle CSA increased significantly at T2 (similar to 2.7 %) and T3 (similar to 10.4 %) versus T1. Similarly, CSA-USecho increasedat T2 (similar to 17.2 %) and T3 (similar to 13.7 %). However, when CSA-USecho was normalized to the increase in muscle CSA, only T2 showed a significantly higher USecho versus T1. Additionally, TV increased at T2 and T3 versus T1, but MVC increased only at T3. Myoglobin and Interleukin-6 were elevated at T2 versus T1, and myoglobin was also higher at T2 versus T3. We propose that early RT-induced increases in muscle CSA in untrained young individuals are not purely hypertrophy, since there is concomitant edema-induced muscle swelling, probably due to muscle damage, which may account for a large proportion of the increase. Therefore, muscle CSA increases (particularly early in an RT program) should not be labeled as hypertrophy without some concomitant measure of muscle edema/damage. (AU) | |
| FAPESP's process: | 14/19594-0 - The role of muscle damage in muscle protein synthesis modulation |
| Grantee: | Felipe Romano Damas Nogueira |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |
| FAPESP's process: | 12/24499-1 - The role of the magnitude of muscle damage in hypertrophic responses |
| Grantee: | Felipe Romano Damas Nogueira |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 13/21218-4 - The role of the magnitude of muscle damage in hypertrophic responses |
| Grantee: | Cleiton Augusto Libardi |
| Support Opportunities: | Regular Research Grants |