Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Thesis 1-5.pdf (7.11 MB)

ETD Abstract Container

Abstract Header

The Effect of a Pre-Exercise Nutritional Supplement on Muscle Fatigue During Handgrip Exercise

Shaw, Aaron P
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1373030510

Abstract Details

2013, Master of Science, University of Toledo, Exercise Science.
The use of pre workout stimulating supplements has been on the rise and continues to increase with athletes and recreationally active humans endlessly seeking methods to improve their performance. This study used a pharmaceutical grade nutritional supplement termed ARK-1©, containing L-arginine which is a precursor to nitric oxide (NO). NO is released from endothelial cells and is important in the regulation of vascular function and muscle blood flow in humans. PURPOSE: To examine the effects of L-arginine on vascular function and muscle blood flow during isometric handgrip to fatigue and to determine if the L-arginine supplement would lead to an increase in exercise tolerance as determined by the time to task failure during a handgrip fatigue test. For comparison purposes, the efficacy of the NO precursor Larginine was determined relative the maximal vasodilatory response of the brachial artery following sublingual administration of 0.4 mg nitroglycerin (GTN) tablet. The shear stress induced, endothelial dependent vascular response was determined using the flowmediated dilation (FMD) technique. METHODS: Thirteen healthy men (23 ± 3 yrs., 88.6 ± 17.5 kg, 183.0 ± 7.3 cm, 16.7 ± 7.7 Kg ·m-2 ; means ± SD) completed an 8 day regimen of L-arginine loading (10g/day). Pre to post measurements of the vascular response (i.e. FMD and GTN) were obtained using B-mode ultrasonography. Mean blood velocity (MBV) was measured using 2-D doppler velocimetery in the left brachial artery during baseline, exercise and recovery. Mean arterial pressure, heart rate, blood flow and vascular conductance were also recorded during rest, exercise and recovery pre and post L-arginine supplementation. Near infrared spectroscopy (NIRS) was used to assess changes in total-[Hb+Mb], deoxy- [Hb+Mb], oxy-[Hb+Mb] and % StO2 on the microcirculatory level over the pulmaris longus and flexor digitorum superficialis muscle in the forearm. Mean arterial pressure (MAP), blood flow (BF), heart rate (HR) and vascular conductance (VC) was also recorded throughout exercise. RESULTS: Pre/post L-arginine baseline arterial diameter FMD and GTN was not different, however the change in arterial diameter pre/post L-arginine was (p<0.05). Time to task failure was longer (p<0.05) following L-arginine supplement compared to pre conditions. The ratio %FMD/ peak shear rate (pre/post) at rest was increased (p<0.05). FMD and GTN measurements for peak shear rate, resting shear stress, and resting arterial diameter (pre/post) conditions were very similar (p>0.05). The cardiovascular responses for MAP, BF, HR and VC showed a time interaction (p<0.05) between all time points during exercise compared to rest independent of condition. NIRS also showed a time interaction between all time points (p<0.05) for total [Hb+Mb], deoxy- [Hb+Mb] and % StO2 also independent of condition when compared to rest. CONCLUSION: These results indicate that eight days of L-arginine supplementation significantly improves the vascular response (both endothelial-dependent and endothelial-independent mechanisms). In addition, it appears that FMD response is independent of the shear stress stimulus since there was no difference in shear stress stimulus following L-arginine supplementation. No difference in peak shear rate was found, however the ratio between %FMD and peak shear rate was increased (p<0.05). This indicates a stimulus in addition to shear rate is acting on the endothelium post L-arginine supplementation. The longer time to task failure following L-arginine supplementation is consistent with an improvement in performance reported in previous studies and may be related to an improvement in muscle blood perfusion and/ or oxygen utilization. Results from NIRS and cardiovascular responses indicate changes normally observed at rest and during exercise at all time points independent of condition.
Barry W. Scheuermann, PhD (Committee Chair)
Suzanne Wambold, PhD (Committee Member)
Michael Tevald , PT, PhD (Committee Member)
150 p.
Kinesiology; Physiology; Sports Medicine

Recommended Citations

Citations

  • Shaw, A. P. (2013). The Effect of a Pre-Exercise Nutritional Supplement on Muscle Fatigue During Handgrip Exercise [Master's thesis, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1373030510

    APA Style (7th edition)

  • Shaw, Aaron. The Effect of a Pre-Exercise Nutritional Supplement on Muscle Fatigue During Handgrip Exercise. 2013. University of Toledo, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1373030510.

    MLA Style (8th edition)

  • Shaw, Aaron. "The Effect of a Pre-Exercise Nutritional Supplement on Muscle Fatigue During Handgrip Exercise." Master's thesis, University of Toledo, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1373030510

    Chicago Manual of Style (17th edition)

toledo1373030510
2,209
© 2013, all rights reserved.
This open access ETD is published by University of Toledo and OhioLINK.