Hormonal Responses From Concentric And Eccentric Muscle Contractions

Discussion in 'Articles & Scientific Studies' started by paymanz, Jun 15, 2016.

  1. paymanz

    paymanz Member

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    Hormonal responses from concentric and eccentric muscle contractions. - PubMed - NCBI

    Abstract
    Intense resistance exercise can acutely increase testosterone (T), free testosterone (FT), and growth hormone (GH) concentrations, but there are few investigations concerning acute endocrine responses to concentric (CON) and eccentric (ECC) contractile actions.

    PURPOSE:
    The purpose of the study was to compare acute anabolic hormonal responses to bouts of dynamic CON and ECC contractions from multiple exercises at the same absolute load.

    METHODS:
    Ten young men (age: 24.7 +/- 1.2 yr, weight: 85.45 +/- 24.2 kg, and height: 178 +/- 0.2 cm) completed two trials in counterbalanced fashion consisting of only CON or ECC contractions at the same absolute workload. Subjects performed four sets of 12 repetitions of bench press, leg extension, military press, and leg curl at 80% of a 10-repetition maximum with 90-s rest periods. Blood samples were collected pre-, post-, and 15-min postexercise.

    RESULTS:
    There were significant increases in GH, T, and FT and lactate for both trials, but only GH and lactate were greater for the CON trial.

    CONCLUSION:
    CON exercise increases GH concentrations to a much greater extent than ECC exercise at the same absolute load, and it is likely that greater GH responses were related to intensity rather than mode of contraction. Also, CON and ECC dynamic contraction trials at the same absolute workload elicited similar small but significant increases in T and FT, indicating that the greater metabolic stress produced by during the CON trial did not affect these hormone responses.

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    one explanation comes to mind is that in ESS workout you need to spend much less energy than CON workout..

    here Comparison of Oxygen Consumption in Rats During Uphill (Concentric) and Downhill (Eccentric) Treadmill Exercise Tests

    this table Comparison of Oxygen Consumption in Rats During Uphill (Concentric) and Downhill (Eccentric) Treadmill Exercise Tests

    they need to doubling slope gradient to make ESS and CON exercise consume equal oxygen.

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    but in testosterone production ESS type still has the edge....
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    it is opposite to what i expected...

    any thoughts?!
     
  2. OP
    paymanz

    paymanz Member

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  3. Lyall

    Lyall Member

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    Perhaps the studies in humans would be more useful or indicative of what is happening.
     
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