Prediction of metabolic and cardiopulmonary responses to maximum cycle ergometry: a randomised study

Abstract

All of the most widely-cited studies for the prediction of maximum exercise responses have utilized either volunteers or referred subjects. Therefore, selection bias, with overestimation of the reference values, is a likely consequence.In order to establish a set of predictive equations for the gas exchange, ventilatory and cardiovascular responses to maximum ramp-incremental cycle ergometry, this study prospectively evaluated 120 sedentary individuals (60 males, 60 females, aged 20±80), randomly-selected from >8,000 subjects. Regular physical activity pattern by questionnaire, body composition by anthropometry and dual energy X-ray absorptiometry (n=75) and knee strength by isokinetic dynamometry were also assessed.Previously reported equations typically overestimated the subjects' peak oxygen uptake (p<0.05). Prediction linear equations for the main variables of clinical interest were established by backward stepwise regression analysis including: sex, age, knee extensor peak torque, bone-free lean leg mass, total and lean body mass, height, and physical activity scores. Reference intervals (95% confidence limits) were calculated: some of these values differed markedly from those formerly recommended.The results therefore might provide a more appropriate frame of reference for interpretation of the responses to symptom-limited ramp incremental cycle ergometry in sedentary subjects; i.e. those usually referred tor clinical cardiopulmonary exercise tests.

Relationship between work rate and oxygen uptake in mitochondrial myopathy during ramp-incremental exercise

“…In the present study, we confirm previous observations that S 2 is steeper than S 1 in normal subjects, probably reflecting the contribution of the O 2 slow component (2,3,5,29). This pattern, however, contrasted with that found in patients with MM who showed a consistently lower S 2 /S 1 ratio at the same pedaling rate compared to normal subjects.…”

“…The samples were lysed before the measurements and values are reported as absolute values and related to peak WR (lactate/WR ratio). The O 2 at the estimated lactate threshold was evaluated by the gas exchange method (GET), with visual inspection of the inflection point of CO 2 with regard to O 2 (modified V-slope) and by the ventilatory method when E/ O 2 and PETO 2 increased while E/ CO 2 and PETCO 2 remained stable (28,29). The average O 2 for the last 15 s was considered to be representative of the subject's peak O 2 (29).…”

Spiroergometrische Referenzwerte für die sozialmedizinische Leistungsbeurteilung bei Erwachsenen im Alter über 60 Jahre

“…3. Lediglich in einer Studie [11] lag die Sauerstoffaufnahme der Personen in den beiden Altersbereichen von 60 bis 69 sowie von 70 bis 79 Jahren unterhalb der Normalbereiche anderer Studien, wobei die Werte für eine Belastung mit 100 W angegeben werden (vgl.…”

“…4). Eine minütliche Steigerung der Belastung mittels Rampenprotokoll führten Pothoff et al [5] und Neder et al [11] durch, was mit einer teilweise deutlich niedrigeren maximalen Sauerstoffaufnahme einherging. Fairbarn et al [10] führ-ten ebenfalls eine Ergometrie mit minütlicher Steigerung um 16 W durch.…”

“…Fairbarn et al [10] führ-ten ebenfalls eine Ergometrie mit minütlicher Steigerung um 16 W durch. Eine gute Übereinstimmung fand sich zur Probandengruppe der 60-bis 69-Jährigen, während in der älteren Gruppe der 70-bis 80-Jährigen wie die von Neder et al [11] berichteten Werte knapp unter den in unserer Studie ermittelten Werten der maximalen Sauerstoffaufnahme lagen. Jones et al [9] belasteten sowohl 10 Männer als auch 10 Frauen im Alter von 55 bis 71 Jahren mit 300 bzw.…”