Respiratory Compensation Thresholds in Healthy Korean Adults / 대한내과학회지

OBJECTIVES: The respiratory compensation threshold(RCT) is thought to be one of parameters by some for the evaluation of physical performance despite its controversial status. The purpose of this investigation is to establish the reference values of the RCT in healthy Korean adults, and to examine the usefulness of this parameter in evaluating physical performance. METHODS: Symptom-limited maximal exercise test by Bruce protocol was carried out, and RCT and AT were determined by the aid of the computerized V-slope method, along with the VO2 max, in 441 healthy Korean adults consisting of 284 men and 157 women aged from 20`s to 60`s. In addition, correlation between RCT and AT was observed, and regression equations of the RCT were also derived. RESULTS: The RCT VO2 was tended to decrease with age in men, but not in women and the RCT VO2 of women was 26-30% less than that of men. The ratio of RCT VO2 to VO2 max (RCT VO2/VO2 max) was tended to increase with age and the RCT V was significantly correlated with AT VC4 and VO2 max in both sexes. CONCLUSION: Our study reveals that the RCT is another useful submaximal index along with the AT in evaluating physical performance. The regression equation of the RCT was RCT VO2(L/min)=1.4232-0.0102 A(age in year)+0.0204 W(weight in kg)-0.4889 S (sex, coded O for males and 1 for females).

Oxygen Uptake, Heart Rate and Oxygen Pulse at Maximal Exercise / 대한내과학회지

OBJECTIVES: Despite the fact that determinations of cadiorespiratory fitness levels by exercise stress tests are becoming widely used in healthy individuals as well as in patients with cardiopulmonary diseases, the normal standards in this field have not been well established in Korea. The purpose of this study is to provide normal standards or reference values for the VO2 max, HR max and O2 pulse max for normal Korean adults by age and sex, along with the derivation of regression formulae of these parameters. METHODS: In 1,000 healthy adults (20-66years) consisting of 603men and 397women, symptomlimited maximal exercise was carried out by Bruce protocol, allowing holding on to the hand rail of the treadmill during exercise for the safety purpose. All the subjects were non-athletes and were members of a health center and were more conscious about their health and physical fitness than the ordinary population. RESULTS: The VO2 max and HR max were decreased with age as expected and, as a whole, the values of the VO2 max and HR max of females were approximately 84% and 90% of those of males, respectively. Estimated yearly reductions in the V max for males and females were 0.45 and 0.32mL/kg/min, respectively and those of the HR max were 0.72 and 0.76/min, respectively. The O2 pulse max of the female was approximately 70% of that of the male, and was slightly related to weight and exercise time. The regression equations of the parameters obtained using exercise time (ET, sec), age (A, year), weight (W, kg) and sex (S, O=male; 1= female) were: HR max=215.3-0.74A-5,04S, O2 pulse max= 5.371+0.216W+0.0107ET-1.505S and VO2 max=40.612+1.950ET-0.206A-0.147W-6.060S, CONCLUSION: The VO2 max in our study was higher than hitherto reported. This was primarily due to longer exercise time of the subjects on the treadmill, because they were allowed to hold on to the hand rail during exercise. And also, the fact that our subjects, being members of a health center, might have had higher physical fitness levels than general population could have contributed to the high VO2 max. Thus, we feel that our results could be the ideal target or- reference values to be achieved for those patients or individuals who have to do the tests with holding on to the rail of a treadmill for safety purpose.

Cardiopulmonary Response to Maximal Exercise Loading in Professional Soccer Players

BACKGROUND: Although maximal exercise stress tests are widely used in the athletic and medical fields, studies on professional soccer players are few. The purpose of our study is to observe the cardiopulmonary response to maximal exercise loading and the AT in professional soccer players. METHODS: Maximal exercise stress tests were carried out by a ramp protocol using a treadmill on 20 professional soccer players with a mean age of 25.2 years and with over 10 career years. The tests were also done on 21 college students majoring in physical education with a mean age of 19.4 years, which served as the control group. The AT was determined by the V-slope method. RESULTS: In the players, the VO2 max, VCO2 max and O2 pulse max were significantly larger than those in the control group, and the HR max was smaller for their ages. The VE max, VT max and RP max showed not much difference between the 2 groups but the VE max/VO2 max and VE max/VCO2 max were significantly lower in the players. The AT was larger in the players but the AT/VO2 max was essentially similar to that of the control group. CONCLUSION: Our study reveals that the professonal soccer players, despite their mean ages were approximately 6 years older than the subjects in the control group, had larger VO2 max and VCO2 max, and smaller HR max for their ages. The VE max was similar in both groups. This suggests that the players have higher aerobic capacity than the control group and exchange respiratiory gases more efficiently.

Cardiorespiratory response to maximal exercise loading in mild anemia

BACKGROUND: Mild iron deficiency anemia is known to be asymptomatic in most of the cases. In view of this, we studied response of the mild anemics to the maximal exercise loading test to learn whether or not they respond similarly to the normals. METHODS: The maximal exercise loading tests by Bruce's protocol were carried out in 22 female asymptomatic anemics with hemoglobin level of between 10.0gm/dL and less than 12.0gm/dL, and the results were compared with those of 44 non-anemic matched controls with mean hemoglobin level of 13.1gm/dL. The ages in both groups were in their 30's to 40's, and even the anemics were otherwise normal clinically and on various laboratory tests. RESULTS: There were no significant difference between two groups in VO2 max, HR max, VCO2 max and VE max and their derivatives including VT/VC and VE/MVV. CONCLUSIONS: Our results indicate that in patients with mild iron deficiency anemia, the cardiorespiratory response to maximal exercise loading is not different from the normals, and suggest that oxygen transport to tissues is not affected even at maximal exercise. probably by adaptive compensatory mechanism.

Comparisions of Electrocardiograms and Echocardiograms in Volleyball Players before and after Intensive Training

BACKGROUND: We attempted to study functional and structural changes in the hearts of volleyball players and cardiac effects of a short-term intensive training as disclosed by electrocardiograms(ECG's) and echocardiograms(UCG's). METHODS: In 12 volleyball players of a university team with the mean age and career of 19.9 and 9.2 years, respectively, comparisons of ECG's and UCG's M-mode & Doppler, were made before and after an intensive training of 8 weeks duration. The players have been trained 2-3 hours daily almost year around for many years, and the intensive and comprehensive training given for the current study was 3 hours daily, which included strenuous interval training of 20-30 minutes. The training was divided into two successive sessions. For the first session, the players ran 4km daily as a part of the training for 2 weeks. The second session included repetition of runnging at their maximal speed with short intermissions of stationary running for 6 weekes. RESULTS: The major findings in ECG's were sinus bradycardia(25.0%) and high voltage(33.3%), and those in M-mode UCG's were left ventricular(LV) hypertrophy, LV dilatation or left atrial dilatation being seen in all cases, alone or in combinations. After the training however, there were no significant changes in the incidences of these abnormal findings in ECG's & UCG's, and also in the mean of various echocardiographic parameters reflecting cardiac functions. The E and A waves in Doppler UCG's also showed no changes. The slight but significant changes after the training were limited to the increases in the mean of the sum of S wave in V1 & R wave in V5, and left atrial dimensions. CONCLUSION: In volleyball players who have been regularly trained for many years, the major findings in ECG's were sinus bradycardia and high voltage. Those in UCG's were LV hypertrophy. LV dilatation or left atrial dilation being seen in all cases, alone or in combinations. Nonetheless, after the intensive training of 8 weeks duration, the incidences of these abnormal findings in ECG's and UCG's remained essentially similar, and slight but significant changes were limited to the increases in the sum of S wave in V1 & R wave in V5, and left atrial internal dimensions. These facts suggest that in the regularly trained volleyball players, a short-term intensive training induces only limited cardiac changes as disclosed by ECG's and UCG's.

Comparisons of Electrocardiograms and Echocardiograms in Soccer Players before and after Intensive Training

BACKGROUND: In athlete's heart, functional and structural alteration are main features. We studied electrocardiograms(ECG's) and echocardiograms(UCG's) in soccer players before and after intensive training. METHODS: Fifteen soccer players with the mean age and career of 19.3 and 8.5 years,respectively,underwent intensive training for 5-5.5 months, which included running of 2 km daily during the last 2-2.5 months. Comparisons of ECG's and UCG's recorded before and after the training were made. RESULTS: The major abnormal finding in pre-training ECG's was high voltage being seen in 40% of the cases, and in UCG's left ventricular(LV) dilatation and/or hypertrophy or asymmetrical septal hypertrophy(ASH) were noted in approximately 80% of the cases. The incidences of these finding after the intensive training were essentially unchanged, and the mean of pre-and post-training fractional shortening(FS) and LV and left atrial dimensions were similar. The high voltage in ECG's showed no close correlation with LV dilatation or hypertrophy on UCG's. After the training, however, the mean values of the thickness of LV posterior wall and ventricular septum along with LV mass were significantly increased, and the right ventricular dimension was significantly decreased. CONCLUSIONS: The most frequent finding in ECG's and UCG's in soccer players, before and after intensive training,were high voltage, LV dilatation and /or hyperophy with or without ASH. The intensive training of 5-5.5 months duration caused no change in F8,but caused significant increase in the thickness of LV posterior wall and ventricular septum, and LV mass.

Effect of intensive training on ventilatory functions in soccer players / 결핵

No abstract available.