caa a22 4500 467941289 CHVBK 20180406153013.0 cr unu---uuuuu 170328e20060301xx s 000 0 eng 10.1007/s00421-005-0094-4 doi (NATIONALLICENCE)springer-10.1007/s00421-005-0094-4 Similar hormonal responses to concentric and eccentric muscle actions using relative loading [Elektronische Daten] [Robert Kraemer, Daniel Hollander, Greg Reeves, Michelle Francois, Zaid Ramadan, Bonnie Meeker, James Tryniecki, E. Hebert, V. Castracane] Conventional resistance exercise is performed using sequential concentric (CON) and eccentric (ECC) contractions, utilizing the same muscle load. Thus, relative to maximal CON and ECC resistance, the ECC contraction is loaded to a lesser degree. We have recently shown that at the same absolute load, CON contractions are associated with greater growth hormone (GH) but similar total testosterone (TT) and free testosterone (FT) responses compared with ECC contractions and attributed the larger GH response to greater relative CON loading. In the present study, we have examined the same endocrine parameters to six different upper and lower body exercises using relative loading rather than absolute loading, hypothesizing that GH responses would be similar for CON and ECC actions, but TT and FT responses would be greater after ECC contractions. Seven young men with recreational weight training experience completed an ECC and CON muscle contraction trial on two different occasions in a counterbalanced fashion. The exercises consisted of four sets of 10 repetitions of lat pull-down, leg press, bench press, leg extension, military press, and leg curl exercises at 65% of an ECC or CON 1-RM with 90s between sets and exercises. CON and ECC actions were performed at the same speed. ECC 1-RMs were considered to be 120% of the CON 1-RM for the same exercise. Blood samples were collected before, immediately after, and 15min after the exercise. GH significantly increased across both trials but was not different between the two trials. Total testosterone was not significantly altered in response to either trial; however, free testosterone concentrations increased in response to both ECC and CON trials. Data suggest that CON and ECC muscle contractions produce similar GH, T, and free testosterone responses with the same relative loading. Springer-Verlag, 2005 Growth hormone nationallicence Testosterone nationallicence Free testosterone nationallicence Muscle contraction nationallicence Kraemer Robert Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut Hollander Daniel Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut Reeves Greg Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut Francois Michelle Department of Nursing, Southeastern Louisiana University, 70402, Hammond, LA, USA aut Ramadan Zaid Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut Meeker Bonnie Department of Nursing, Southeastern Louisiana University, 70402, Hammond, LA, USA aut Tryniecki James Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut Hebert E. Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut Castracane V. Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Center, 79106, Amarillo, TX, USA aut European Journal of Applied Physiology Springer-Verlag 96/5(2006-03-01), 551-557 1439-6319 96:5<551 2006 96 421 https://doi.org/10.1007/s00421-005-0094-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-005-0094-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kraemer Robert Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Hollander Daniel Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Reeves Greg Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Francois Michelle Department of Nursing, Southeastern Louisiana University, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Ramadan Zaid Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Meeker Bonnie Department of Nursing, Southeastern Louisiana University, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Tryniecki James Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Hebert E. Department of Kinesiology and Health Studies, Southeastern Louisiana University, SLU 10845, 70402, Hammond, LA, USA aut NATIONALLICENCE 700 1- Castracane V. Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Center, 79106, Amarillo, TX, USA aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/5(2006-03-01), 551-557 1439-6319 96:5<551 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer