RESEARCH QUARTERLY

pulse above the resting rate. Individuals with a low resting pulse
tend to show a greater increase in pulse rate due to mild exercise and
those with the higher resting rates are least affected.

Subtracting the resting rate from the post-exercise rate does, to
some extent, counter-balance the effect of the resting pulse rate
upon the post-exercise pulse rate following strenuous exercise. This
counterbalancing effect does not operate at the milder intensities
of exercise.

A comparison of the mean exercise rates with the resting rates
shows that a mild exercise (10 steps) increases the pulse only ap-
proximately 30 per cent over the resting level. An intermediate
exercise (20 or 30 steps) produces only about a 40 per cent in-
crease, while a more strenuous exercise (40 steps) results in more
than a 90 per cent elevation in rate.

The Rate of Pulse Deceleration Following Graded Intensities of
Exercise —The pulse deceleration after exercise may be measured
by comparing the rate during the first thirty seconds after an exer-
‘cise with the rate during the second thirty seconds after the same
exercise. Observations of the post-exercise pulse deceleration of
eleven normal male adults are summarized below:

 

 

 

Steps per Mean Correlation with
Minute Deceleration SD, Resting Pulse
10 5.19 3.03 —.640
20 10.91 5.91 —.228
30 14.45 3.60 —.064
40 15.64 12.76 135

 

The post-exercise pulse deceleration rate is inversely related to
the resting rate at the mildest intensity of exercise. The greater
increase in beats due to the mild exercise in individuals with low
resting pulse rates is accompanied by a much faster fall in rate after
the exercise. At the strenuous exercise level this relationship does
not exist.

By comparing the mean deceleration rates, it is noticed that the
deceleration rate increases as the exercise rate is increased.

The Occurrence of a Secondary Rise in Pulse Rate after Exer-
cise in Individuals with Normal and in Cases of Abnormal Hearts —
Following the first fall in pulse rate after exercise there is observed
occasionally a secondary rise in pulse rate. This secondary rise
usually occurs at about one and one-half minutes after the exercise
and is observed to increase as much as ten beats per one-half minute.
This rise occurs most frequently after the more strenuous exercises
and lasts for about one-half to three minutes.

In order to study the frequency of the occurrence of a secondary
rise in heart rate following exercise in individuals with normal hearts