Biomedical subjects

J H Doust

Publications and source records attributed to J H Doust.

20 records · Page 2Linked to original sources

PubMed1995

Lack of reliability in Conconi's heart rate deflection point.

Conconi et al. (1982) reported the development of noninvasive field test for anaerobic threshold (AT) based upon an observed deviation from the linear heart rate (HR)--running velocity (RV) relationship at high RV (HRdev). While the validity of the Conconi test has been debated (Heck and Hollmann 1992; Tokmakidis and Leger 1992), the reliability of the Conconi test has never been independently assessed in athletes performing the protocol outlined by Conconi. This study evaluated the reliability of the Conconi test in 15 well-trained male distance runners (22.5 +/- 3.3 yrs, 67.7 +/- 4.8 kg, VO2 peak 66.4 +/- 4.8 ml.kg-1.min-1) who performed a treadmill simulation of the Conconi test protocol twice within a 4-8 day period. The results were as follows: 6 subjects demonstrated HRdev in both Conconi tests, 5 subjects demonstrated HRdev in only one test, and in 4 subjects HRdev could not be discerned in either test. It was concluded that failure to determine a reproducible HRdev by subjective assessment in 9 of 15 subjects makes the Conconi test unsuitable for reliable evaluation of AT.

Adult↗

PubMed1981

The limitation of exercise ventilation during speech.

Ventilation in steady-state treadmill exercise at five different speeds has been measured in six subjects using an inductance plethysmograph whose calibration is described. A printed passage of 100 words was read aloud during the fifth minute of each exercise period:this took about 30 sec. At each exercise level ventilation was reduced during speech to about 55% of the control value: at the highest level the reduction was 38 1. min-1 from a control ventilation of 78 1. min-1. Respiratory frequency was reduced but tidal volume was not affected. Twenty-four per cent of the ventilation during the speech period at the heaviest exercise was accounted for by non-phonated (silent) expirations. Immediately after the speech period, ventilation overshot by about 14% and then returned to the control value within 30 sec. The results are interpreted in terms of the precedence taken by the speech requirement for restricted expiratory airflow rates over the ventilatory requirement for gas exchange.

Humans↗