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Biomedical subjects

T D Fahey

Publications and source records attributed to T D Fahey.

14 recordsLinked to original sources
PubMed1993

The effects of intermittent liquid meal feeding on selected hormones and substrates during intense weight training.

This study examined the effects of feeding a liquid meal during weight training on selected hormones and substrates. Ten male subjects were given a meal (MW) or nonnutritive placebo (W) before and intermittently during a 2-hr weight training session, and a meal before and intermittently during 2 hours of rest (M). Serum insulin increased from 12.2 +/- 1.2 and 11.2 +/- 1.3 before feeding to 37.2 +/- 4.8 and 45.0 +/- 5.0 mU.ml-1 during exercise in MW and M, respectively, and remained elevated for 120 min. Insulin remained at resting levels in W throughout the experiment. Glucose increased from 5.20 +/- 0.16 and 4.82 +/- 0.20 before feeding to 6.23 +/- 0.30 and 6.0 +/- 0.36 mmol.l-1 at the beginning of exercise in MW and M. Glucose declined during the first 15 min of exercise in MW and M but remained at or above resting levels for 120 min in MW. Lactate increased above 5.9 mmol.l-1 in W and MW during exercise. Glucagon remained unchanged in all groups. Perceived exertion during exercise was 8.5 +/- 0.16 for MW and 8.3 +/- 0.18 for W. Feeding a liquid meal before and during weight training exercise can increase serum insulin and maintain blood glucose for a prolonged period.

Adult↗
PubMed1992

The effects of sodium bicarbonate and pyridoxine-alpha-ketoglutarate on short-term maximal exercise capacity.

The purpose of this study was to determine the effects of the simultaneous use of pyridoxine-alpha-ketoglutarate (PAK) and sodium bicarbonate (NaHCO3) on short-term maximal exercise capacity in eight well-trained male cyclists. The study consisted of the determination of maximal power output and the administration of various combinations of placebos, PAK and NaHCO3, followed by a short-term maximal exercise test. To determine maximal power output (power(max)), the subjects performed a continuous, incremental test on a Monark bicycle ergometer to symptom limited maximum (test 1). To determine the effects of NaHCO3 and PAK on short-term maximal exercise performance, the subjects were administered either placebo (PLA), PAK and sodium bicarbonate (P/B), PAK and placebo (PAK), or sodium bicarbonate and placebo (BIC) prior to performing short-term maximal exercise (test 2). Oral tablets of NaHCO3 and PAK were given in doses of 200 mg kg-1 and 50 mg kg-1 respectively. The subjects pedalled at the power output corresponding to 100% of their VO2 max at 70 rev min-1 until voluntary cessation or until they were unable to maintain pedal revolution rate. Venous blood samples were drawn at rest (RES), cessation of exercise (CES) and after 2 min of recovery (REC) and analysed for lactate, pH and bicarbonate ion concentration. The subjects attained an average maximum power output of 377 +/- 20 W during the graded maximal pre-test (test 1). There were no significant differences between treatments in the ability to sustain power(max) during test 2. During test 2, the subjects were able to sustain power(max) for 7.6 +/- 4.3 min with P/B, 6.7 +/- 2.9 min with PAK, 7.3 +/- 4.9 min with BIC and 6.9 +/- 2.7 min with placebo (mean +/- S.E.). Blood lactate (BLa) was significantly elevated at cessation of exercise and remained elevated during recovery, but there were no significant differences between treatments. Bicarbonate fell significantly during exercise and recovery in each treatment. At rest, bicarbonate levels were significantly higher in both the P/B and BIC than in the PAK or PLA treatments. Pooled data from the P/B and BIC treatments demonstrated a significant increase in pH at rest and end of exercise when compared to PLA treatment. These data suggest that sodium bicarbonate rather than PAK was responsible for this increase. In summary, our data suggest that in the dosages used in this study, administration of sodium bicarbonate or PAK, alone or in combination, is ineffective in increasing short-term maximal exercise capacity.

Adult↗
PubMed1991

The effects of ingesting polylactate or glucose polymer drinks during prolonged exercise.

Five trained, fasted male cyclists rode a cycle ergometer three times at 50% of VO2max for 180 min. Using a balanced order, double-blind procedure, subjects were given either a solution containing polylactate (PL: 80% polylactate, 20% sodium lactate, in 7% solution with water), glucose polymer (GP: multidextrin in 7% solution with water), or control (C: water sweetened with aspartame) 5 min before exercise and at 20-min intervals during exercise. Venous blood samples were taken at rest and at 20-min intervals during exercise. In general, PL and GP rendered similar results except that pH and bicarbonate (HCO3-) were higher in PL. There were no differences between treatments in perceived exertion, sodium, potassium, chloride, lactate, heart rate, oxygen consumption, rectal temperature, or selected skin temperatures. These data show that polylactate may help maintain blood glucose and enhance blood buffering capacity during prolonged exercise and could be a useful component in an athletic fluid replacement beverage.

Adult↗
PubMed1990

A comparison of blood gases and acid-base measurements in arterial, arterialized venous, and venous blood during short-term maximal exercise.

The purpose of this study was to determine the relationship between blood gases and acid-base measurements in arterial, arterialized venous, and venous blood measured simultaneously during short-term maximal exercise. Ten well-trained male cyclists performed a graded maximal exercise test on a cycle ergometer to determine the power output corresponding to their peak oxygen consumption (test I), and a short-term maximal test on a cycle ergometer at peak power output (test II). During test II arterial, arterialized venous and venous blood were sampled simultaneously for determination of partial pressures of oxygen and carbon dioxide, pH, bicarbonate (HCO3-), base excess (BE), and lactate (La). Samples were taken at rest, the end of 1 min of exercise (1 ME), at the end of exercise (EE), and at 2 min of recovery (REC). During test II, subjects maintained a peak power output of 370.6 (62.1) W [mean (SD)] for 4.5, SD 1.6 min. Except at rest venous and arterialized venous measurements tended to be the same at all sampling intervals, but differed significantly from measurements in arterial blood (P less than 0.05). BE was the only variable that rendered consistently significant correlations between arterial and arterialized venous blood at each sampling interval. The pooled correlation coefficient between arterial and arterialized venous BE was r = 0.83 [regression equation: BEa = (0.84 BEav)-0.51]. Arterial La was significantly higher than venous La at 1 ME (2.8, 0.7 vs 0.8, 0.3 mmol.l-1) and higher than both venous and arterialized venous La at EE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Influence of sex differences and knee joint position on electrical stimulation-modulated strength increases.

This study examined the influence of sex differences and knee joint position on the effectiveness of isometric electrical stimulation in improving isometric and isokinetic strength. Twenty-seven females and 28 male subjects were assigned to either a control group (C) that received no electrical stimulation, to an experimental group that received stimulation of the quadriceps with the knee flexed at 65 degrees (EF), or to an experimental group that received electrical stimulation of the quadriceps with the knee fully extended (EE). Experimental subjects received 15 min of electrical stimulation 3 times/wk for a total of 6 wk. Before and after the study, knee extension strength was measured with a Cybex II, isometrically at 65 degrees of knee flexion and isokinetically at 30 degrees . s-1, 60 degrees . s-1, 90 degrees . s-1, and 120 degrees s-1. Multivariate analysis of covariance, using the pretests as the covariate, revealed no sex differences in responsiveness to electrical stimulation. EF was superior to EE at 30 degrees . s-1 and 120 degrees . s-1 in females and at 120 degrees . s-1 in males (P less than 0.05). Male and female EF was superior to C in all tests. EE was higher than C at isometric, 30 degrees . s-1, 90 degrees . s-1, and 120 degrees . s-1 in females and at isometric and 30 degrees . s-1 in males. These data suggest that electrical stimulation at the quadriceps can increase isometric and isokinetic strength and may be more effective in improving isokinetic strength if the knee is flexed during treatment.

Adult↗
PubMed1982

The effects of electrical stimulation of normal quadriceps on strength and girth.

The effect of surging faradic electrical stimulation on the strength and girth of normal quadriceps was studied in 18 young adult females (9 experimental and 9 control). Both quadriceps of the experimental subjects received 10 treatments of 15-min duration of electrical stimulation administered over a 5-week period. Before and after the study, thigh girth was measured and knee extension strength assessed with a Cybex II, Isometrically at 65 degrees of knee flexion and isokinetically at 30 degrees/s and 60 degrees/s. There were no differences between groups in high girth. Isometric strength increased 31% in the non-dominant leg and 21% in the dominant leg (P less than 0.05). The only significant change in isokinetic strength was found in the non-dominant leg at 30 degrees/s. Surging intermittent faradic stimulation can develop both types of strength at slow speeds of motion. Such stimulation should be valuable modality for developing isometric strength when normal voluntary motion is hampered. However, it appears to have little applicability to developing the kind of strength associated with rapid movements.

Adult↗
PubMed1976

Serum testosterone, body composition, and strength of young adults.

The relationship between serum testosterone (ST), body composition, and static strength was studied in 26 college females and 16 male college football players. In addition, the transient effect of weight training on ST was studied in 10 college males (5 skilled and 5 unskilled weight trainers), 12 male high school students, and 5 female college students. ST, measured by radioimmunoassay, ranged from 333.7 to 848.1 ng/100 ml in males, and from 32.8 to 121.5 n/100 ml in females. The high school subjects had significantly lower levels of ST. Correlations between serum testosterone, body composition (measured by densitometry), and static strength (grip and backlift) were nonsignificant in males and females. Comparisons of subjects with the highest and lowest levels of testosterone within each sex showed no significant differences in strength or body composition. Serum testosterone increased 111.4 +/- 96.l ng/100 ml (X +/- SX) following a weight training session in the male college group, but failed to increase in the college females or high school males. There were no significant differences in testosterone increases between the skilled and unskilled male weight trainers. Maximal exertion may be necessary for an increase in serum testosterone to occur. Lack of an increase in testosterone by high school males or college females may have been due to a submaximal effort during the weight training exercise.

Adolescent↗
PubMed1975

Venous and capillary blood hematocrit at rest and following submaximal exercise.

The purpose of this study was to determine if finger tip capillary blood hematocrit is a valid estimate of anticubital venous blood hematocrit at rest and after submaximal exercise. Simultaneous samples of finger tip cpaillary and venous blood were drawn from thirty-one subjects (15 males, 16 females) before and after a 15 min submaximal exercise on a bicycle ergometer. Venous and capillary blood hcts. were 42.0% +/- 3.9 and 42.0% +/- 3.5 respectively before exercise and 43.3% +/- 3.5 and 42% +/- 3.8 after exercise (X +/- s). The regression equation for predicting venous hct. from finger tip capillary blood after exercise was: Hctv = 0.87 Hctc + 6.44 with r = 0.95 (P less than 0.05). The results indicate that the finger tip capillary microhematocrit method is a valid indicator of venous blood hct. following exercise.

Blood Specimen Collection↗
PubMed1975

Body composition and Vo2max of exceptional weight-trained athletes.

The maximal oxygen uptake and body composition of 30 exceptional athletes who have trained extensively with weights was measured. The sample included 3 world record holders, 8 other world class athletes, and 19 national class competitors. The sports represented were shot-putting, discus throwing, body building, power lifting, wrestling, and olympic lifting. Vo2max as determined on a bicycle ergometer by the open-circuit method was 4.6 +/- 0.7 1-min-1 (mean +/- SD) (48.8 +/- 7 ml-kg-1., 56.4 +/- 8.6 ml-(kg LBW)-1). The mean maximal heart rate was 185.3 +/- 11.6 beats-min-1. The subjects attained a work rate of 1,728.2 +/- 223 kpm-min-1 on a continuous progressive bicycle ergometer test and had mean maximal ventilations of 152.5 +/- 27.7 1-min-1 BTPS. Body composition was determined by densitometry. Body weight averaged 96.0 +/- 14.9 kg, with mean percent fat of 13.8 +/- 4.5. The results of this study indicate that exceptional weight-trained athletes are within the normal college-age population range in body fat and of somewhat higher physical working capacity.

Adipose Tissue↗