Biomedical subjects

Samuel A Headley

Publications and source records attributed to Samuel A Headley.

4 recordsLinked to original sources

PubMed2006

The acute effect of aerobic exercise on brachial artery endothelial function in renal transplant recipients.

This study compared the effect of a 30-minute walk on brachial artery endothelial vasodilatation in kidney transplant (KT) recipients and healthy controls (HCs). Endothelial-dependent vasodilatation was measured by ultrasound before and after exercise. The HCs experienced a significant increase in vasodilatation after exercise 1 minute postocclusion when compared with the KT recipients (22%+/-13% vs 3%+/-4%; P<.05). Also, the HCs had a significantly higher vasodilatation from pre-treadmill walk to post-treadmill walk (1 minute postocclusion) when compared with KT recipients (from 3%+/-6% to 22%+/-13% vs 1%+/-3% to 3%+/-4%; P<.05). This acute vasodilatory response observed in the HCs may be related to the immediate release of nitric oxide and the combined response to shear stress and exercise. The KT recipients had several coronary artery disease risk factors that may have adversely affected endothelial function.

Adult↗

PubMed2004

IGF-I system responses during 12 weeks of resistance training in end-stage renal disease patients.

OBJECTIVE: To examine the hypothesis that 12 weeks of resistance training would alter circulating concentrations of IGF-I system components in end-stage renal disease (ESRD) patients. DESIGN: Ten ESRD patients underwent 12 weeks of resistance training after a 6 week control period and had morning fasted blood drawn on four occasions (weeks - 6, 0, 6, 12). Immunoassays were performed for serum total and free IGF-I, IGF binding proteins (IGFBPs) 2 and 3, and the acid labile subunit (ALS). Immunoaffinity depletion of ALS-based complexes allowed measurement of non-ternary (i.e., binary) IGF-I and IGFBP-3. RESULTS: Significant improvements in strength and functional performance were observed. All IGF-I measures were stable during the control period and no changes were observed for the first 6 weeks of resistance training. At week 12, total IGF-I (-15.4+/-28.9%), ternary IGF-I (-16.4+/-36.7%), and the IGF-I/IGFBP-3 ratio had significantly (p < or = 0.05) declined from week 0 values. No changes were observed for free IGF-I, IGFBPs 2 and 3, or the acid labile subunit. The proportion of IGF-I in ternary ( approximately 76.3+/-6.8%), non-ternary ( approximately 22.5+/-6.6%), and free ( approximately 1.2+/-0.5%) forms remained constant throughout the training. CONCLUSIONS: 12 weeks of resistance training in ESRD patients induced a decline in total IGF-I, but did not alter the proportion of IGF-I circulating in free, ternary or non-ternary molecular complexes. The decline in IGF-I occurs in the presence of positive training adaptations on physical performance and we conclude that this response pattern appears to be reflective of favorable neuromuscular anabolic adaptations.

Adult↗

PubMed2004

The Robinson Protocol: a treadmill anaerobic performance test.

The current investigation was designed to further examine the reliability of the Robinson protocol, which is a run-to-exhaustion treadmill test. Robinson (10) originally examined this protocol with 5 subjects. The significance of the initial exploratory study was the impetus for expanding the study to examine the reliability of the protocol with a larger sample. Fifteen male subjects participated in 3 trial runs on the treadmill. The first trial was a modified McConnell (7) test to determine the aerobic capacity of each subject. The second and third trials were identical Robinson protocols (10). The first trial run mean, in seconds (262.04 +/- 74.50), was not significantly different from the second trial run mean (257.30 +/- 72.65), p = 0.526 (2 tailed). As expected, trial 1 and trial 2 were highly correlated (intraclass) (r = 0.927, p < 0.001). These results provide additional support for the hypothesis that the Robinson protocol with a greater subject pool is a reliable protocol that can be used in research studies interested in examining various physiological interventions or anaerobic training.

Adolescent↗

PubMed2004

The effects of yoga training and a single bout of yoga on delayed onset muscle soreness in the lower extremity.

The purpose of this study was to determine the effects of yoga training and a single bout of yoga on the intensity of delayed onset muscle soreness (DOMS). 24 yoga-trained (YT; n = 12) and non-yoga-trained (CON; n = 12), matched women volunteers were administered a DOMS-inducing bench-stepping exercise. Muscle soreness was assessed at baseline, 24, 48, 72, 96, and 120 hours after bench-stepping using a Visual Analog Scale (VAS). Groups were also compared on body awareness (BA), flexibility using the sit-and-reach test (SR), and perceived exertion (RPE). Statistical significance was accepted at p </= 0.05. A 2 x 2 mixed factorial ANOVA with repeated measures at 24 and 48 hours revealed a significant (p < 0.05) group main effect with VAS scores greater for CON than YT. Paired t-tests revealed that in YT, VAS scores were higher before yoga class than after yoga class at 24 hours (21.4 [+/- 6.9] mm vs. 11.1 [+/- 4.1] mm; p = 0.02). The SR was greater in YT than in CON (65.0 [+/- 7.9] cm vs. 33.3 [+/- 7.0] cm; p < 0.01); however, no differences were found between yoga and control in BA (94.0 [+/- 4.4] units vs. 83.8 [+/- 3.7] units; p = 0.21) or in RPE at 5-minute intervals (2.9 [+/- 0.3], 5.3 [+/- 0.8], 5.8 [+/- 0.9], and 5.2 [+/- 0.8] vs. 2.5 [+/- 0.3], 4.0 [+/- 0.5], 4.2 [+/- 0.3], and 4.9 [+/- 0.4]. Yoga training and a single bout of yoga appear to attenuate peak muscle soreness in women following a bout of eccentric exercise. These findings have significant implications for coaches, athletes, and the exercising public who may want to implement yoga training as a preseason regimen or supplemental activity to lessen the symptoms associated with muscle soreness.

Adult↗