DISCOVERY 



67 



or slackened. Everyone knows that severe exercise 

 is not only accompanied, but followed, by severe 

 respiration, and in this subsequent ' recovery process " 

 considerable quantities of oxygen are taken in ; indeed, 

 recent experiments in Manchester by two colleagues 

 of mine (Messrs. Lupton and Long) have run this 

 " recovery oxygen " up to lo litres, enough to maintain 

 a man in bed for nearly an hour ! Actuallj-, of course, 

 a man cannot lie in bed without oxj-gen for an hour ; 

 his brain and heart require a continual suppl}' of 

 oxj^gen. But it is a striking fact that by severe 

 exercise lasting for less than a minute a man may 

 incur a debit balance of oxygen which would be suffi- 

 cient to keep him comfortably in bed for about an 

 hour. Looked at in another way, lo litres of oxygen 

 cannot be supplied through the circulation in less 

 than about 2i minutes, even with the most violent 

 respiratory effort. Thus in less than a minute it is 

 possible to incur a debt which it will take one's heart 

 and lungs 2h minutes to repay, even when working at 

 their hardest ; for a short time one may expend 

 energy several times as fast as one coujd possibly do 

 if one were dependent on a simultaneous supply of 

 oxj'gen. These facts illiisiratc the advantage to the 

 body of the latitude allowed by the syste»i of paying 

 later on for its efforts in the immediate present. 



Athletic Records 



Let us now consider some world's athletic records, 

 and the conditions affecting them. The Amateiu' 

 Athletic Association, I believe, " passes " records made 

 upon the track ; the Physiological Society ought to 

 undertake to " pass " records made in the laboratory ! 

 There are two quantities in which the world's records 

 are of fundamental physiological interest : (a) the 

 maximvmi oxygen debt which it is possible for a man 

 to incur, and [b) the maximum intake of oxygen per 

 minute during severe exercise. Both, properly speak- 

 ing, should be reckoned per kilogram of body-weight, 

 though this has not been done here. Both records are 

 held by members of the University of Manchester, one 

 by a Professor and the other by a Bachelor of Science. 

 It might advance physiological knowledge were 

 Oxford and Cambridge to give a " fuU blue" to 

 oxygen-intake representatives, and a " half blue " to 

 those able to incur the greatest debit balance (of 

 oxygen) ; such contests might even be included in 

 the 01>Tnpic Games. It is quite certain anyhow that 

 the Professor and the Bachelor of Science will soon be 

 ousted from their present proud positions as holders of 

 world's records.^ 



1 The Professor's record still stands, but the Bachelor's record 

 has been beaten by over 3 litres, by a Y.M.C.A. sportsman of 

 forty-six years. 



Let US consider what these records mean. The 

 Professor, who weighs 73 kilos, has managed, by 

 vigorous running, to utilise 4,175 c.c. of oxygen in a 

 minute. Assuming i c.c. of his arterial blood to con- 

 tain about 0-185 c.c. of oxygen — the normal amount — 

 and I c.c. of his mixed venous blood to contain about 

 0-650 c.c. of oxygen — it could not have contained much 

 less — then every I c.c. of his blood, as it travelled 

 round his body during the exercise, must have lost 

 0-12 c.c. of oxygen. Thus to take in 4,175 c.c. of 

 oxygen it must have required about 35 litres of blood 

 to pass through the heart and lungs per minute — a 

 mass of blood equal to that of half the body every 

 minute ! There are few water taps \\-hich will turn 

 out 35 litres (9 gallons) every minute, and yet the heart 

 can do it, probably in a first-class runner for an hour 

 on end ; it is small wonder that the heart is one of 

 the parts most likelj' to fail when the machine is 

 overloaded. Of course there are not 35 litres of 

 blood in the Professor's body — probably only about 5 

 — so that the whole of it has to circulate seven times 

 every minute. 



The record held by the Bachelor of Science is 10 

 litres ; by extremely violent jumping over a stool in 

 a cellar (strange things happen in physiological labora- 

 tories) he produced fairly complete exhaustion, and in 

 the succeeding 10 minutes took in 10 litres more of 

 oxygen than he would have needed had he remained 

 at rest. He must have produced not far from the 

 lactic-acid-maximum in his muscles. Now these two 

 gentlemen are admittedly world champions only on 

 false pretences ; merely because no first-class athletes 

 have tried to oust them from their championships. 

 There can be little doubt that W. G. George in his 

 prime, or even our present-day mile champions, could 

 put up a record of at least 5 litres per minute for 

 the intake, while a half-mile champion " run out " to 

 the last ounce could probably incur an oxygen debt of 

 at least 15 litres. This is prophecy ; but, were betting 

 not forbidden by the rules of the A.A.A. (if not, at 

 present, by those of the Physiological Society), I should 

 be prepared to back the prophecy with cash ! 



The Limit of Speed 



Let us now consider some further world's records — 

 the times of the flat races from 100 yds. to a mile. 

 Suppose a man to run on the level at a constant 

 measured speed, and let us determine the value of his 

 oxygen consumption per metre travelled. We all know 

 that it is a greater effort to run 100 yds. fast than to 

 run it slowly, and it is found that the oxygen con- 

 sumption increases with the speed. Indeed, the 

 oxygen needed per metre travelled is approximately 

 proportional to the speed. Hence, the oxygen needed 

 per minute should be approximately proportional to 



