One hundred and eighty-one sedentary middle-aged business and professional men, all members of the. "EPIC Health Club Inc", were engaged in a physical.
ORIGINAL ARTICLES
Blood pressure reduction in "borderline"
hypertensives following physical training Gaston
Choquette,
m.d., f.a.c.c. and Ronald J.
Ferguson,
ph.d., Montreal
It has been well established that hypertension is a ma¬ factor in coronary heart disease (CHD).1 At present, one of the most accepted practices in the pre¬ vention of CHD is to reduce an elevated blood pres¬ sure. In the prospective study of Framingham, Kannel, Gordon and Schwartz2 have well established that even normotensive. At the conclusion of the program "borderline" hypertension is associated with an in¬ both groups exhibited significant reductions in systolic creased incidence of CHD as compared with normotenand diastolic blood pressures at rest and after sion. The objective of this report is to present the submaximal work. Moreover, the reductions of the effects of a six-month physical conditioning program on of the exercise and diastolic and resting systolic (300 kg.m./min.) systolic blood pressures were significantly the blood pressure of "borderline" hypertensive and normotensive men. greater for the hypertensives.
Summary: One hundred and sixty-five middle-aged, apparently normal men were submitted to a six-month conditioning program. On the basis of a casual blood pressure measurement during the pre-training evaluation, 37 individuals (23%) were classified as "borderline" hypertensive. The remaining subjects (n = 128) were
Resume: Cent
soixante-cinq hommes d'age moyen,
bonne sante, furent soumis a un programme de reconditionnement pour une periode de six mois. Selon le niveau de la pression arterielle enregistree durant I'evaluation qui preceda I'entrainement, les sujets furent divises en deux groupes, soit 37 (23%) hypertendus "borderline" et 128 normotendus. Les
apparemment
en
hypertendus "borderline" presentaient une pression systolique de 140 a 159 mm Hg et/ou une pression diastolique de 90 a 95 mm Hg. La pression
arterielle des normotendus etait inferieure
140/90
mm
jor risk
a
Hg.
A la suite du programme, chacun des deux groupes
montre une reduction significative des pressions systolique et diastolique aussi bien au repos qu'a I'effort a
sous-maximal. De plus, les reductions des pressions systolique et diastolique au repos et de la pression systolique a I'effort (300 kg.m/min.) furent significativement plus grandes chez les hypertendus que chez les normotendus. En conclusion, les resultats de la presente etude suggerent que les hypertendus "borderline" aussi bien que les normotendus ont diminue leur pression arterielle au cours de I'entrainement mais que les hypertendus semblent en avoir tire un plus grand Wnefice.
Medicine, Montreal Physical Education, University of Montreal. Supported in part by the "Jean-Louis Levesque Foundation". Reprint requests to: Dr. Gaston Choquette, Montreal Heart Institute, 5000 Belanger St. E., Montreal 410, P.Q.
From the Departments of Research and Heart Institute and the Department of
Material and methods One hundred and eighty-one sedentary middle-aged business and professional men, all members of the "EPIC Health Club Inc", were engaged in a physical conditioning program for a period of approximately six months starting in the fall of 1969. Prior to the training program, all subjects were given a medical evaluation which included health history, physical examination, chest radiography, resting 12-lead electro¬ test on an cardiography and a multi-stage work capacity Elema-Schonander bicycle ergometer. The ergometer was used to determine the physical working capacity 150 (PWC150), i.e. the workload in kg.m./min. needed to bring about a heart rate of 150. The resting ECG and the multi-stage work test were repeated at the end of the training period. The work test3 consisted of pedalling continuously in the upright position at a constant speed (60 r.p.m.) for a total of 19 minutes. Three 6-minute workloads of increasing intensity were followed by 1 minute of was pedalling without resistance. The ECG (V4andlead) record¬ continuously monitored on an oscilloscope at rest sited for 10 seconds while the subject was The workload. of each end the at and on a bicycle ting heart rates, measured from the ECG during the last minute of the first two workloads (300 and 450 kg.m./ min.), were used to estimate the third workload by ejxtrapolating to a heart rate of 150 (Fig. 1). Where a C.M.A. JOURNAL/MARCH 17, 1973/VOL. 108 699
heart rate of 150 beats/min. could not be maintained
The work test
was
discontinued if the heart rate
during the last minute of the third workload, the exact reached 140 or more by the end of the first or the PWCiso was calculated by plotting on graph paper the second workload. "fhe appearance of chest pain compa¬ experimental values obtained at the three different tible with angina pectoris, with or without ST depres¬ workloads and extra- or interpolating to a heart rate sion, or of significant supraventricular or ventricular of exactly 150. A similar protocol has been suggested arrhythmias was an indication for the immediate cesin a report of the World Health Organization on Re¬ sation of the test. habilitation of Patients with Cardiovascular Diseases.4 Among the 181 subjects who performed the exercise Blood pressures were measured by auscultation of the right brachial artery using a Tycos sphygmomano175 meter with a 14x60 cm. cuff. The pressure at which the sound disappeared was taken as the diastolic pres¬ sure. The measurements were taken at rest sitting on 165 the bicycle and during the last minute of work at 300 and 450 kg.m./min. 155
160h X
160
-*»
workload 3
E E
145
(predicted) \140
135
O ©
1130
Training
125
Pre Post 120
Hypertensives
115 110 h
100
¦
a
(n-37)
Normotensives 300
400
600
600
700
J800
J900
WORK (kgm/min) FIG. 1.Prediction of third workload to be applied on bicycle ergometer as calculated from heart rates observed at workloads of 300 and 450 kg.m./min. respectively.
(n=128)
105h
v300
450/
REST
WORK (kgm/min) FIG. 3.Pre- and post-training systolic blood pressure means of hypertensives and normotensives at rest and during the sixth minute of work at 300 and 450 kg.m./min.
Training
128
Hypertensives
(n 37) Normotensives (n=128)
Pre Post ¦
n
.
O
=
_
120
c
£
^ o 0) -O
95"
112 CD
X
. o
104
o 4>
96
E E
Training Pre Post
Hypertensives
(n=37)
88
Normotensives
(n=128)
80 1
REST
J_L 460 J
300
WORK
(kgm/min)
FIG. 2.Pre- and post-training heart rate means of hypertensives and normotensives at rest and during the sixth minute of work at 300 and 450 kg.m./min. 700 C.M.A. JOURNAL/MARCH 17, 1973/VOL. 108
90
^85 "5
8 80
x REST
v300 WORK
J. 450
(kgm/min)
FIG. 4.Pre- and post-training diastolic blood pressure means of hypertensives and normotensives at rest and during the sixth minute of work at 300 and 450 kg.m./min.
were excluded from the present study. The included: definite or suspected coronary insuf¬ ficiency, systolic blood pressure of 160 mm. Hg or greater and/or diastolic pressure exceeding 95 mm. Hg during rest sitting on the bicycle, or the inability to complete the two preliminary workloads of 300 and 450 kg.m./min. Among the 165 remaining subjects, 37 were classi¬ fied as "borderline" hypertensive according to their pre-training blood pressure measured during rest sit¬ ting on the bicycle just before starting the exercise. "Borderline" hypertension, as arbitrarily defined by Kannel, Gordon and Schwartz2 is the presence of either a systolic pressure of 140 to 159 mm. Hg or a diastolic pressure of 90 to 95 mm. Hg or both. The
test, 16
reasons
Table I
Description of "borderline" hypertensives and normotensives before training
blood pressure of the remaining 128 subjects was be¬ low 140/90 mm. Hg. The "borderline" hypertensive subjects were not informed of their blood pressure measurements and were not grouped for their condi¬ tioning program. The conditioning program, two-hour weekly ses¬ sions from October to April, consisted of group exercises such as calisthenics, jogging and volley-ball. A swim and shower period of 20 to 30 minutes was included at the end of each session. Following the examples given during the group sessions, the sub¬ jects were advised to perform calisthenics at home for 10 to 15 minutes daily. No special instructions were given regarding diet and smoking. The statistical analysis of the data was made using the Student's t-test for paired values obtained before and after training on the same subjects and by the reg¬ ular Student's t-test when the hypertensive group was compared with the normotensive. Results
t Values are means db standard deviations tfWeight (lbs.) X 100 Height (ins.)2 Table II PWCiso (kg.m./min.) of hypertensives and normoten¬ sives before and after training
t Values are means **P < 0.01
±
standard deviations
Table III Resting and exercise heart rate and blood pressure of before and after training
fValues are means
**P < 0.01
db
The mean age, weight, height and Quetelet Body Mass Index (BMI)56 of both groups before training are list¬ ed in Table I. During training there was no statistical change in mean weight for either the hypertensive (1§4.0 to 184.2 lbs.) or the normotensive (171.1 to 170.8 lbs.) group. Both groups showed significant (P
