In order to elucidate effects of the exercise intensity on purine catabolism, we performed exhausitve exercise (Exh-ex), 80% VO₂max exercise (80%-ex) and 70% VO₂max exercise (70%-ex) test by a bicycle ergometer, and estimated the purine catabolism by the changes in blood ammonia, plasma oxypurines and urinary oxypurines in five healthy male subjects who were given allopurinol. The results were summarized as follows;
1) Plasma oxypurines concentrations (POP) increased gradually after exercise with each intensity. The order of their maximal levels and of cumulative areas under the curves of POP were exh-ex>80%-ex>70%-ex>control, respectively, and that of urinary excretions of oxypurines was exh-ex>80%-ex>70%-ex≥control.
2) Blood ammonia concentrations (BNH₃) increased sharply after exercise with each intensity. The order of their maximal levels was 80%-ex = exh-ex>70%-ex>control, and that of cumulative areas under the curves of BNH₃ was 80%-ex>exh-ex>70%-ex>control.
3) Blood lactate concentrations (BLA) increased sharply after exercise with each intensity. The order of their maximal levels and of cumulative areas under the curves of BLA were exh-ex =80%-ex>70%-ex>control, respectively.
These results suggest that the purine catabolism leading to uric acid production is activated by the physical exercise in the order of increasing intensities. The discrepancy between the increase in ammonia and those in oxypurines suggests that the increased purine catabolic pathway was mediated not only by AMP deamination but also by other factors.

View full abstract

The purpose of the present study was to derive regression equation based on anthropometric measurements to estimate pulmonary residual volume (RV) and to ascertain its applicability in calculation of body density (BD) . Subjects were 30 males and 25 females living in Santa Barbara, California, USA, ranging in age 17 to 52 years.
Nine anthropometric measurements, actual RV, vital capacity (VC), and BD using the conventional underwater weighing method were made on each subject. In males four measurements (age, height, biiliac diameter, and chest diameter) were selected by Wherry-Doolittle test selection method. Likewise, four measurements (height, age, shoulder circumference, and chest diameter) were selected in females. The prediction formulas obtained by using these measurements were as follows:
(1) RV=38.89 (X1) +30.43 (X2) -12.43 (X3) +10.70 (X4) -4573.4 (formales)
(R=0.832, SEE =251.9 ml)
where RV: predicted RV (ml), X1: age (years), X2: height (cm), X3: biiliac diameter (mm), X4: chest diameter (mm), R: multiple correlation coefficient, SEE: standard error of estimation.
(2) RV=26.21 (X1) +8.71 (X2) -4.71 (X3) +12.94 (X4) -1284.2 (for females)
(R=0.768, SEE =225.9 ml)
where X1: height (cm), X2: age (years), X3: shoulder circumference (mm), X4: chest diameter (mm) .
When these formulas were used to calculate RV, mean absolute differences between BDs obtained by using measured and the predicted RVs were 0.00331 g/cm³ for males and 0.00353 g/cm³ for females. On the other hand, the absolute differences using the formula of Goldman and Becklake, the fractions of VC, and the constant values were 0.0047 g/cm³, 0.00763 g/cm³, and 0.00787 g/cm³ for males, 0.00642 g/cm³, 0.00646 g/cm³, and 0.00620 g/cm³ for females respectively.
It was concluded that using the formulas obtained in the present study to predict RV would be a useful method in the situation where mass management were nessesary and more precise measurements were required than the other simplified estimations. Because in predicting RV our formulas could largely diminish the extent of the potential error as compared with the other predictions. In addition they would not require special knowledge, technique, and devises.

View full abstract

Exercise intensity is one of the major determinats in the exercise prescription, where THR plays an important role. This study was designed to reemphasize the usefulness of the Karvonen's formula with special regard to the anaerobic threshold (AT) in the exercise prescription to middle-aged healthy men. Fifty normal adult subjects between 30 and 59 years who were refered to the Life Planning Center for the evaluation of physical fitness were selected for the study. Symptom limited maximal treadmill stress testing after Bruce's protocol was performed for all subjects and AT was determined as the level, where the minute ventilatory volume curve during exercise revealed the first breaking point. The heart rate at AT (HR_AT) was compared to those obtained by the Karvonen's formula (k=0.6) and the other conventional method, in which the 70% and 85% of the maximal heart rate (HRmax) were determined as an optimal range for the exercise intensity. The following results were obtained: the average value of HRAT just coincided with the THR obtained with Karvonen's formula and its±1 S.D. values just fitted into the range of 70% and 85% of HRmax, respectively. THR by the Karvonen's formula varies with k values and is mostly affected by the resting heart rate (HRr) . If the k is fixed to 0.6, THR thus obtained can keep its range between 70% and 85% of HRmax under the normal range of HRr (mean±2 S. D. ; 37-116 bpm) . Moreover, THRs obtained from the Karvonen's formula (k=0.6) using the age predicted HRmax were best fitted into the ones derived from the HRmax obtained by the maximal exercise testings. Thus, THR detemined by the Karvonen's flrmula (k=0.6) can be the most suitable with regard to the anaerobic threshold and the most reliable within the wide range of normal resting heart rate.

View full abstract

The purpose of this study was to measure the effectiveness of RPE on exercise intensity for senior citizens. A maximum workload test was administered with the use of a bicycle ergometer on older male and female subjects. The results of our study can be summarized as follows:
1. Two trials were performed on separate days. A high correlation coefficient for the first trial and the second trial was found. The reliability for the male group was r=0.76 (p<0.01) and that for the female group r=0.90 (p<0.01) .
2. A correlation range of r=0.55-0.79 (p (0.01) was found for RPE and physiological exercise intensity (which includes oxygen intake and heart rate) . A higher result was found when the relative value was used in the analysis of the oxygen intake and the heart rate instead of the absolute value.
3. Significant correlation coefficients of r=0.63-0.64 (p<0.01) were found for RPE and the work load in terms of watt units.
4. The majority of the physiological variables were statistically determined ; however, there were no correlations between RPE and systolic blood pressure.
In conclusion, based on our study, we have found that RPE and HR ; RPE and %Vo₂max: RPE and watts grouped individually had a high correlation for effectiveness. The only exception in our study was the RPE and the blood pressure group because no correlation was found overall. Therefore, the overall effectiveness of RPE was proven to be quite sensitive even for senior citizens, and as a result RPE can be utilized when exercise is prescribed for evaluatory measurement in senior citizens.

View full abstract

The purpose of this study was to elucidate the changes in systolic and diastolic time intervals which accrue along with increase of HR during a prolonged exercise.
Fifteen male collegiate distance runners performed bicycle ergometer exercise of 70% maximal oxygen intake for 60 minutes. Electrocardiogram, phonocardiogram, pulse wave using ear densitogram and its derivative were recorded throughout the exercise, and then HR, STI, DT (diastolic time) and QS₂/DT were caluculated from the tracings.
The results obtained are as follows:
1. At the initial phase of the exercise, DT decreased markedly to result in rapid increase of QS₂/DT. When HR was between 130-150 beats/min, however, the rate of decrease of QS₂ was greater than that of DT, so QS₂/DT showed a tendency to decrease. When HR was more than 150, QS₂ reached a plateau but DT still continued to decrease, and QS₂/DT turned to increase again.
2. LVET decreased slowly throughout the exercise, whereas PEP decreased rapidly within initial two minutes and kept a steady state thereafter. The change in QS₂ after two minutes of exercise seemed to depend on LVET.
3. LVETi and QS₂i showed a similar change as that in QS₂/DT but the change in QS₂i was less obvious than that in LVETi.
4. PEN and PEP/LVET decreased rapidly in the initial two minutes, thereafter they continued to increase more slowly with increase of HR until the end of exercise.
Conclusively, HR continued to increase monotonously during prolonged exercise of a constant intensity, while systolic and diastolic time intervals varied the directions and patterns of their changes during the exercise.

View full abstract

This study was carried out to examine the following. 1) For 20 adult males in summer, cold-induced vasodilation (CIVD) immersed in ice water (ice water CIVD) and CIVD exposed to cold air of 0°C, -5°C and -10°C (cold air CIVD) were compared. The blood pressure was measured and examined during the course of measuring ice water CIVD and -10°C cold air CIVD. 2) -10°C cold air CIVD was measured in summer and in winter for 40 males.
The results for 1) and 2) are summarized as follows.
1. Definite effects of the difference in thermal transmission rate was observed between cold air CIVD and ice water CIVD. Finger skin temperature fell as the temperature at cold air CIVD dropped to 0, -5 and -10°C. At -10°C cold air CIVD where the drop of skin temperature was greatest, the temperature at first rise (TFR) was higher, time of temperature rise (TTR) was longer and amplitude of temperature (AT) was greater, compared with the respective values at ice water CIVD. However, no difference was observed in mean skin temperature (MST) during the exposure. Individual difference in values at cold air CIVD was greater than that at ice water CIVD.
2. The time of maximum rise of blood pressure response after cold exposure was 5 minutes at ice water CIVD and 20 minutes at -10°C cold air CIVD. The rate of blood pressure rise at -10°C cold air CIVD was significantly greater. The time when the rise of blood pres-sure reached the maximum was identical with the time when the skin temperature became lowest.
3. At -10°C cold air CIVD, MST and TFR were higher and TTR shorter in winter than those in summer. At ice water CIVD, the values in summer were higher for MST and TFR and shorter for TTR as mentioned previously.
4. The temperature before -10°C cold air CIVD (TB) showed a significant correlation with MST and TFR, though not with TTR.
5. A comparison of these results with Watanuki et al.'s report reveal some differences.

View full abstract