INTERRELATION OF RESPONSES DURING PROGRESSIVE EXERCISE IN TRAINED AND UNTRAINED SUBJECTS

In twelve cyclists (‘trained’ group) and twelve sedentary subjects (‘untrained’ group) the cardiovascular, pulmonary and metabolic responses to submaximal cycle ergometer exercise have been investigated. Lower values for ventilation (VE), heart, rate (HR), cardiac output (VQ), respiratory exchange ratio (R) and blood lactate (La) were found in the trained group. When related to oxygen intake as percentage of predicted maximum the responses of VE, HR and Q were similar in the two groups but values for La remained lower in the trained subjects. It was concluded that a more rapid and more efficient distribution of cardiac output occurred in the trained group. Five ‘trained’ and four ‘untrained’ subjects were studied during maximal work. Similar values for Q, HR and La were found in both groups; VE was higher and constituted a significantly higher proportion of the ventilatory capacity (sustained M.V.V.) in the trained compared with the untrained group (81 per cent and 66 per cent respectively). In both groups the rate at which ventilation increased as maximal loads were approached may have led to a ventilatory limitation to further work.