Effect of treadmill exercise on asthmatic children Larry James, M.D., Judith Faciane, B.S., and R. Michael Sly, M.D., F.A.A.A. New Orleans, La.
Measurement of peak expiratory jlow rate before and after treadmill wall&g repeated at hourly intervals in asthmatti ohildren aieclosea progressive decreases in exercise-indnoed asthma. Treadmill running was followed by more extreme exeroiseinduced bronchospasm than treadmill wallcing. Exercise-induced asthma occurred in some children whose heart rates did not reach 160 &ring treadmill exe&se, and heart rate dnring exercise was not correlated with the extent of exerdse-induced bronohospasm.
Wheezing following exercise has been recognized in asthmatics at least since the second century A.D.~ Although this phenomenon has been studied extensively and some methods of prevention and treatment have been identified, the basic cause(s) remain obscure.2-11 To investigate further this response, the effect of two different types of treadmill exercise upon pulmonary function was studied in asthmatic children ; the effect of repeated treadmill exercise was evaluated, and possible relationships between exercise-related changes in pulmonary function and heart rate were sought. MATERIALS
AND
METHODS
All subjects were patients in the pediatric allergy clinics at Charity Hospital of Louisiana at New Orleans, Louisiana State University Division, and all were known to have had recurrent, reversible, airway obstruction. They were otherwise unselected except by their willingness to participate. Bronchodilators and cromolyn sodium were withheld for at least eight hours prior to testing. Peak expiratory flow rate (PEFR) was measured using a Wright peak flow meter, adult model. For each measurement the best of three efforts that agreed within 10% was recorded. Response to exercise was expressed as percent change in PEFR, calculated using the formula : PEFR
before exercise - PEFR efter PE’FR before exercise
exeroise x loo
From the Department of Pediatrics, Louisiana State University Medical Received for publication Feb. 19, 1975. Accepted for publication April 1, 1975. Reprint requests to: Dr. R. Michael Sly, Louisiana State University Tulane Ave., New Orleans, La., 70112. Vol. 57, No. 5, pp. 408-416
Center.
Medical
Center,
1542
Effect
VOLUME 57 NUMBER 5
of treadmill
exercise
409
Exercise period
FIG. 1. Maximal o/0 change asthmatic children.
in PEFR following
treadmill
walking
at hourly
intervals
in
Exercise period 0 P e 8 -& Qgj 58
-10
3;
-20
3.s 38 Q % * FIG. 2. Maximal o/o change asthmatic children. Sequential
-30 -40 in PEFR following
treadmill
walking
at hourly
intervals
in 10
exercise
To evaluate responses to sequential exercise, asthmatic children were asked to walk on a treadmill for 8 min (3 mph, 20% grade) at 1-hr intervals. Sixteen children exercised twice; 12, 3 times; and 10, 4 times, because it was inconvenient for six to remain to complete four exercise tests. PEFR was measured immediately before exercise, immediately after exercise, and 5 and 10 min after completion of exercise. Walking
versus
running
Fifteen asthmatic children were asked alternately either to run on a treadmill for 6 min (3 mph, 15% grade) or to walk on the treadmill for 8 min (3 mph,
410
James,
Faciane,
and Sly
TABLE I. PEFR before
(T) and
J. ALLERGY CLIN. IMMUNOL. MAY 1976
after
(F) treadmill
walking
repeated
at hourly
intervals
in 16
First hour
p;trWCt&d
)
6’
1
10’
a
B
:
332.0 471.0 318.0
215 410 210
220 440 225
1.55 360 190
155 285 185
4 z
252.5 287.5 394.0
150 235 120
115 215 165
110
110
75
115
ii
277.0 360.0
305 185
225 210
150 1::
190 ii
1;
249.0 325.0 326.6
115 100 204.5
115 120 205 +0.2
:i 137.5 -33
1:: 142 -31
11
263.0 346.0 322.9
2:
250 230 211 -3
215 150 145 -33
225 240 157 -27
f:
360.0 387.0
305 90
305 155
260
260 70
f ii
408.0 432.5 341.4
415 325 233
390 345 233
2:: 305 165 -29
265 350 177 -24
Subject 1
Mean (N = 10) Mean % change 12
Mean (N = 12) Mean % change (N - 12)
Mean(N = 16) Mean ‘%change (N - 16)
216
0
209%grade). Two hours after completion of one type of exercise, the other type was performed. Eight children ran first ; 7 walked first. Peak expiratory flow rate was measured immediately before exercise, immediately after exercise, and 5 and 10 min after completion of exercise. Relationship
of PEFR to heart
rate
To evaluate the possible relationship between heart rate and postexercise bronchoconstriction, 16 asthmatic children walked on a treadmill for up to 8 min (3 mph, 20% grade). One subject could tolerate exercise for only 6 min and another for only 6$$ min. Eleven of the 16 patients who exercised by walking on the treadmill were also asked to run on the treadmill for 6 min (3 mph, 15% grade). The order for the two types of exercise was alternated; 6 ran first, and 5 walked first. Five children were asked to walk only because it would have been inconvenient for them to remain long enough to complete both types of exercise. For both periods of exercise, PEFR was measured immediately before exercise, immediately after exercise, and 5 and 10 min after completion of exercise. Heart rate was recorded immediately before exercise and monitored and recorded at lmin intervals during exercise.* *Model 504 Heart Rate Monitor, Parks Electronics Laboratory,
Beaverton, Ore. 97005.
Effect
VOLUME 57 NUMBER 5
asthmatic
Second
41 1
6
lL/min)
hour 1
5’
10’
230 155 340 135 100 90 235 190
295 215 440 145 150 is0 310 220 125 80 213 +8
2:: 165 75
Measurement of peak expiratory jlow rate before and after treadmill wall&g repeated at hourly intervals in asthmatti ohildren aieclosea progressive decreases in exercise-indnoed asthma. Treadmill running was followed by more extreme exeroiseinduced bronchospasm than treadmill wallcing. Exercise-induced asthma occurred in some children whose heart rates did not reach 160 &ring treadmill exe&se, and heart rate dnring exercise was not correlated with the extent of exerdse-induced bronohospasm.
Wheezing following exercise has been recognized in asthmatics at least since the second century A.D.~ Although this phenomenon has been studied extensively and some methods of prevention and treatment have been identified, the basic cause(s) remain obscure.2-11 To investigate further this response, the effect of two different types of treadmill exercise upon pulmonary function was studied in asthmatic children ; the effect of repeated treadmill exercise was evaluated, and possible relationships between exercise-related changes in pulmonary function and heart rate were sought. MATERIALS
AND
METHODS
All subjects were patients in the pediatric allergy clinics at Charity Hospital of Louisiana at New Orleans, Louisiana State University Division, and all were known to have had recurrent, reversible, airway obstruction. They were otherwise unselected except by their willingness to participate. Bronchodilators and cromolyn sodium were withheld for at least eight hours prior to testing. Peak expiratory flow rate (PEFR) was measured using a Wright peak flow meter, adult model. For each measurement the best of three efforts that agreed within 10% was recorded. Response to exercise was expressed as percent change in PEFR, calculated using the formula : PEFR
before exercise - PEFR efter PE’FR before exercise
exeroise x loo
From the Department of Pediatrics, Louisiana State University Medical Received for publication Feb. 19, 1975. Accepted for publication April 1, 1975. Reprint requests to: Dr. R. Michael Sly, Louisiana State University Tulane Ave., New Orleans, La., 70112. Vol. 57, No. 5, pp. 408-416
Center.
Medical
Center,
1542
Effect
VOLUME 57 NUMBER 5
of treadmill
exercise
409
Exercise period
FIG. 1. Maximal o/0 change asthmatic children.
in PEFR following
treadmill
walking
at hourly
intervals
in
Exercise period 0 P e 8 -& Qgj 58
-10
3;
-20
3.s 38 Q % * FIG. 2. Maximal o/o change asthmatic children. Sequential
-30 -40 in PEFR following
treadmill
walking
at hourly
intervals
in 10
exercise
To evaluate responses to sequential exercise, asthmatic children were asked to walk on a treadmill for 8 min (3 mph, 20% grade) at 1-hr intervals. Sixteen children exercised twice; 12, 3 times; and 10, 4 times, because it was inconvenient for six to remain to complete four exercise tests. PEFR was measured immediately before exercise, immediately after exercise, and 5 and 10 min after completion of exercise. Walking
versus
running
Fifteen asthmatic children were asked alternately either to run on a treadmill for 6 min (3 mph, 15% grade) or to walk on the treadmill for 8 min (3 mph,
410
James,
Faciane,
and Sly
TABLE I. PEFR before
(T) and
J. ALLERGY CLIN. IMMUNOL. MAY 1976
after
(F) treadmill
walking
repeated
at hourly
intervals
in 16
First hour
p;trWCt&d
)
6’
1
10’
a
B
:
332.0 471.0 318.0
215 410 210
220 440 225
1.55 360 190
155 285 185
4 z
252.5 287.5 394.0
150 235 120
115 215 165
110
110
75
115
ii
277.0 360.0
305 185
225 210
150 1::
190 ii
1;
249.0 325.0 326.6
115 100 204.5
115 120 205 +0.2
:i 137.5 -33
1:: 142 -31
11
263.0 346.0 322.9
2:
250 230 211 -3
215 150 145 -33
225 240 157 -27
f:
360.0 387.0
305 90
305 155
260
260 70
f ii
408.0 432.5 341.4
415 325 233
390 345 233
2:: 305 165 -29
265 350 177 -24
Subject 1
Mean (N = 10) Mean % change 12
Mean (N = 12) Mean % change (N - 12)
Mean(N = 16) Mean ‘%change (N - 16)
216
0
209%grade). Two hours after completion of one type of exercise, the other type was performed. Eight children ran first ; 7 walked first. Peak expiratory flow rate was measured immediately before exercise, immediately after exercise, and 5 and 10 min after completion of exercise. Relationship
of PEFR to heart
rate
To evaluate the possible relationship between heart rate and postexercise bronchoconstriction, 16 asthmatic children walked on a treadmill for up to 8 min (3 mph, 20% grade). One subject could tolerate exercise for only 6 min and another for only 6$$ min. Eleven of the 16 patients who exercised by walking on the treadmill were also asked to run on the treadmill for 6 min (3 mph, 15% grade). The order for the two types of exercise was alternated; 6 ran first, and 5 walked first. Five children were asked to walk only because it would have been inconvenient for them to remain long enough to complete both types of exercise. For both periods of exercise, PEFR was measured immediately before exercise, immediately after exercise, and 5 and 10 min after completion of exercise. Heart rate was recorded immediately before exercise and monitored and recorded at lmin intervals during exercise.* *Model 504 Heart Rate Monitor, Parks Electronics Laboratory,
Beaverton, Ore. 97005.
Effect
VOLUME 57 NUMBER 5
asthmatic
Second
41 1
6
lL/min)
hour 1
5’
10’
230 155 340 135 100 90 235 190
295 215 440 145 150 is0 310 220 125 80 213 +8
2:: 165 75
