POST-EXERCISE HEART RATE

strenuous enough to command near-maximum amounts of pulse
acceleration which tend to overshadow disturbing factors in the en-
vironment. During the light exercises the mildly accelerated pulse
is easily further accelerated by extraneous stimuli which make post-
exercise pulse readings at these intensities unreliable.

The Pulse Frequency for Thirty Seconds Following Stool-Step-
ping Exercises of Graded Intensity—Following observations of the
pulse frequency for thirty seconds after stool-stepping exercises, the
relationship between the immediate post-exercise pulse and the rest-
ing pulse rate was established. Eleven normal male adults were
observed in this experiment. The data collected on these subjects is
summarized as follows:

 

 

 

Steps per Mean Pulse per %4 Correlation with
Minute Min. after Exercise S:D: Resting Rate

10 41.36 5.65 534

20 46.45 5.83 o13

30 53.73 4.89 746

40 62.18 7.14 .603

 

The correlation of the pulse immediately after thirty and forty
steps with the resting rate is significant at the 1 per cent level of
confidence. Correlations of resting rate with milder exercises although
statistically insignificant are also consistently high. An examination
of the mean pulse rates for one-half minute following ten, twenty,
thirty, and forty stool steps per minute reveals that a direct relation-
ship exists between the post-exercise pulse and the intensity of the
exercise.

The Increase in Pulse Frequency Over the Resting Rate Follow-
ing Stool-Stepping Exercises of Graded Intensity.—What effect does
subtracting the resting rate from the rate immediately after exercise
have upon the relationship between the post-exercise rate and the
resting rate? Using the data collected from the above subjects, the
resting pulse frequency for thirty seconds was subtracted from the
pulse frequency for the first thirty seconds immediately after four
stool-stepping exercises. Correlations of these products with the
resting rates were made and are summarized in the following table:

Steps per Correlation with
Minute Resting Rate

10 —.644

20 —.401

30 —.402

40 —.020

Although the correlations are too low to be highly significant, at
every intensity of the exercise, a negative correlation is found to
exist between the resting pulse and the increase in the post-exercise