This study examined the effect of vitamin B-6 supplementation and exhaustive
submaximal exercise on plasma catecholamine concentrations, and the relationship
between plasma catecholamines and fuel use, heart rate and oxygen consumption. Five
trained men (age= 18-35 years; V0₂max=53 ml 0₂/kg/min.) participated in two controlled
dietary periods that were identical except for the addition of 20 mg/d pyridoxine (PN)
supplementation during the second period. On the seventh morning of each period, fasted
subjects exercised to exhaustion on a cycle ergometer at 74.5% ± 7.8 V0₂max. Blood
was drawn pre-exercise (twice), 60 minutes into exercise, immediately post-exercise and
60 minutes post-exercise. Plasma was analyzed for norepinephrine, epinephrine, glucose,
pyridoxal 5'-phosphate (PLP), lactic acid, glycerol and free fatty acids (FFA). Heart rate
and oxygen consumption were measured pre-exercise and at 10-minute intervals during
exercise. Mean plasma PLP concentration was significantly higher during the
supplemented versus the nonsupplemented trial at all time points. There were no
statistically significant differences in mean plasma catecholamine concentrations or mean
plasma fuel concentrations between the nonsupplemented and supplemented trials at any of
the time points examined. There were significant changes in the mean plasma
concentrations of norepinephrine, lactic acid, glycerol and FFA over time in both trials.
Respiratory exchange ratios (R) were higher during the supplemented trial compared to the
nonsupplemented trial, but the differences did not attain statistical significance. There
were no significant differences in mean exercise times to exhaustion or mean heart rates
between the trials. The overall mean oxygen consumption during exercise was
consistently higher during the supplemented versus the nonsupplemented trial and the
difference attained significance (p=0.016) at one time point (10 min.). The mean oxygen
consumption during rest was lower during supplementation versus nonsupplementation,
but the difference was not statistically significant. The percent plasma volume change
(PVC) was significantly greater at post-exercise, relative to pre-exercise, during the
supplemented versus the nonsupplemented trial. The percent PVC also increased
significantly over time during the supplemented but not the nonsupplemented trial. These
results suggest that 20 mg/d of vitamin B-6 supplementation does not effect plasma
catecholamine concentrations, fuel utilization or heart rate at rest or during submaximal
exercise to exhaustion. The results may suggest a higher oxygen consumption during
exhaustive exercise after PN supplementation. / Graduation date: 1996
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27440 |
| Date | 05 April 1996 |
| Creators | Young, Jennifer Charity |
| Contributors | Leklem, James E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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