A modified Nylin cardiorespiratory test employing a three-step portable staircase

Abstract 1. 1. A simplified Nylin cardiorespiratory test is presented. A small, easily made and portable staircase is substituted for the larger one ordinarily used. The step rate is set by an ordinary metronome. Four rounds on the small staircase are mechanically equivalent to one round on the large one. Oxygen consumptions were recorded with the Krogh apparatus before and after exercise. 2. 2. Fifty-one double tests were performed with 22 healthy subjects and 9 pathologic cases (15 men and 16 women). One double test includes the recording of O 2 consumptions before exercise and after exercise on both staircases, about half an hour elapsing between the two rounds in the latter case. Three different exercises were tried, 5(20) 88 , 5(20) 160 , and 10(40) 160 ; 5(20) 88 signifies 5 rounds on the big staircase or 20 rounds on the small one at a pace of 88 steps per minute. 3. 3. The values obtained with the small and the big staircases do not differ significantly and the differences are numerically very small. The mean difference was 0.25 ± 0.63 c.c. or 0.07 per cent. The highest difference was 11 c.c. Thus, both tests may be used indiscriminately, and the normal values reported earlier for exercise 5 160 on the larger staircase may be applied in judging values obtained with the small staircase. 4. 4. Normal values for the test 5 160 have been given earlier. As regards exercises 5 88 and 10 160 , however, the present values may be used until larger series have been accumulated. The upper normal limit would then be: for men, 5 88 –44 per cent , 10 160 –88 per cent ; and for women, 5 88 –41 per cent , 10 160 –84 per cent . 5. 5. The post- and pre-exercise O 2 consumptions are positively correlated. Regression lines and 2σ limits for the normal cases have been indicated in Figs. 7 and 8.