Health, Exercise, and Sports Sciences ETDs

Publication Date

9-1-2015

Abstract

Human growth hormone (HGH) in response to resistance training has been suggested to be correlated with the muscle hypertrophy adapted to resistance training. The purpose of this study was to investigate whether or not adding a Wingate sprint to a circuit weight training session would optimize the acute HGH response to exercise. Methods. Seven recreational resistance-trained male subjects (n=8) performed 4 exercise trials in a balanced order: 1) a Wingate sprint only(W), 2) a circuit weight training session (C), 3) a Wingate sprint prior to circuit weight training session (WC), 4) a Wingate sprint following circuit weight training session (CW). Blood samples were collected at rest prior to each exercise trial, and at 5, 10, 20, 30, 45, and 60 min post cool-down for all trials. The Wingate sprint was against a resistance of 7% of the subjects body mass (0.7Nm/kg) on a cycle ergometer. The circuit weight training session was a full body workout (40%-50% 1RM for circuit 1 and 70% 1RM for circuit 2 and 3) consisting of 6 exercises in the following exercise order — bench press, bent-over barbell row, smith machine squat, seated dumbbell shoulder press without back support, Romanian deadlift, and latissiumus dorsi pull-down. HGH was measured at the respective time for blood collections. Blood lactate concentration and rate of perceived exertion (RPE) were measured immediately after exercise and prior to cool-down in each trial. Results. Both the WC and CW trials resulted in significant increases in serum HGH concentrations up to 30 min post cool-down. The C trial resulted in a significant increase in serum HGH concentration up to 20 min post cool-down. No significant increase in serum HGH concentration post cool-down was found after the W trial. The CW trial resulted in: 1) significantly higher blood lactate concentration and RPE compared to other trials (p<.05), 2) a significantly higher serum HGH concentration compared to the W and the C trials at 20 min post cool-down (p<.05), 3) a significantly higher HGH concentration compared to the C and the WC trials at 30 min post cool-down (p<.05), 4) a significantly higher HGH AUC compared to the C and the W trials (p<.05), 5) a significant higher peak HGH concentration compared to the C trial (p<.05). No significant difference was found in peak power, mean power, fatigue ratio, and peak cadence between all trials. No correlation was found between blood lactate concentration and HGH AUC, blood lactate concentration and peak HGH, and age and HGH AUC. Conclusion. The CW might produce greater muscle adaptation from exercise compared to other trials.'

Keywords

Growth hormone, Wingate, Circuit weight training

Sponsors

University of New Mexico, Graduate Professional Student Association.

Document Type

Dissertation

Language

English

Degree Name

Exercise Science

Level of Degree

Doctoral

Department Name

Health, Exercise, and Sports Sciences

First Advisor

Kravitz, Len

First Committee Member (Chair)

Mermier, Christine

Second Committee Member

Schneider, Suzanne

Third Committee Member

Dokladny, Karol

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