This study examined the differences in post-exercise hypotension between males and females taking oral contraceptives. The researchers found that the magnitude of the decrease in blood pressure after exercise was significantly greater in females compared to males. While cardiac output and heart rate increased more for males after exercise, ejection fraction increased more for females. The phase of the oral contraceptive cycle did not influence these gender differences in cardiovascular responses to exercise.

1. Gender Differences in Postexercise Hypotension: Influence of Phase of Oral Contraceptive Use.
Joseph I. Esformes*, Keith P. George†, FACSM, and Karen M. Birch‡
*Cardiff School of Sport, University of Wales Institute, Cardiff, CF23 6XD, UK
†Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 2ET, United Kingdom
‡Centre for Sport and Exercise Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
AMERICAN COLLEGE OF SPORTS MEDICINE ∙ 54TH ANNUAL MEETING ∙ NEW ORLEANS, LOUISIANA ∙ MAY 30 – JUNE 2, 2007
[4] RESULTS
Haemodynamics at rest and postexercise did not
differ with OC phase (P > 0.05; Table 1). Significant
PEH was observed in all subjects (P < 0.05), with
the magnitude of the nadir in all blood pressure
variables being significantly greater (P < 0.05) in
females compared to males [11±7 vs 4±1, 11±6 vs
5±1, 9±5 vs 4±1 for systolic (Fig. 2), diastolic (Fig. 3)
and mean arterial blood pressure (Table 1),
respectively], whilst no interactions between gender
and phase of OC use were reported (P > 0.05).
Cardiac output (CO; Fig. 4) and heart rate (HR;
Fig.4) increased transiently postexercise and
displayed gender by time interactions (P < 0.05),
with a greater initial rise in CO in males than in
females (31% vs 20 %) due to a larger increase in
HR (26 % vs 5 %). Ejection fraction (Table 1) in
females initially increased by 6% compared to rest,
whilst in males it remained below baseline values for
40 min of recovery revealing a gender by time
interaction (P < 0.05). Postexercise calf blood flow
was greater in males than females (2.9±1.0 mL∙100
mL-1∙min-1 vs 2.0±0.9 mL∙100 mL-1∙min-1; P < 0.05),
as a result of a significantly lower (P < 0.05) mean
calf vascular resistance in males (46±21 units vs
34±12 units in females; Table 1). No gender by time
interactions were reported (P > 0.05).
[5] CONCLUSION
• The magnitude of postexercise hypotension is
greater in females receiving oral contraceptives
compared to males.
• There were distinct gender differences in the
cardiovascular mechanisms underpinning PEH but
these were not influenced by the phase of OC use.
[6] REFERENCES
Kaufman, FL et al. (1987). Med Sci Sports Exerc.
19(1):17-20.
Kenney, MJ & Seals, DR (1993). Hypertension.
22(5): 653-64.
This study was supported by the Centre for Sport
and Exercise Sciences of the University of Leeds.
[1] INTRODUCTION
A transient decrease in blood pressure immediately
post-exercise has been shown to occur both in
animal models as well as in normotensive and
hypertensive individuals (Kaufman et al., 1987;
Kenney and Seals, 1993), termed postexercise
hypotension (PEH). The role of PEH is potentially
significant in designing first line strategies against
hypertension. Gender differences in the magnitude
and pattern of PEH may be influenced by the
phases of oral contraception (OC) use.
[2] AIM
To examine central and peripheral haemodynamics
regulating PEH following moderate-intensity
exercise in moderately active normotensive males
and females. The impact of OC phase upon
potential gender differences was examined by
investigating females in two phases of OC use.
[3] METHODS
• We studied 8 females (age: 21±1 yr) during the
consumption (CP) and withdrawal (WP) phases of
OC use and 8 males (age: 21±0.7 yr) on 2
separate occasions (M1 and M2).
• Central and peripheral haemodynamics were
recorded via echocardiography and venous
occlusion plethysmography (Fig. 1), before and for
45 min following 30 min of cycle ergometry at 80%
of the lactate threshold.
Figure 1. Left: Venous occlusion plethysmography in the
lower limb. Right: A, 2-D left ventricular long axis view
sonograph. B, Left ventricular M-mode taken at the mitral
valve leaflets. RV: right ventricle; LV: left ventricle.
100
105
110
115
120
125
130
135
140
BL 5 10 15 20 25 30 35 40 45
Time (min)
SBP(mmHg)
CP
WP
M1
M2
*
** ** ** ** ** ** ** **
-12.0
-11.0
-10.0
-9.0
-8.0
-7.0
-6.0
-5.0
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
5 10 15 20 25 30 35 40 45
Times
ΔDBP(mmHg)
CP
WP
M1
M2
*
2
3
4
5
6
7
8
9
BL 5 10 15 20 25 30 35 40 45
Time (min)
CO(L∙min-1
)
Females
Males
*
** ** ** ** ** **
*** ***
40
45
50
55
60
65
70
75
80
85
90
BL 5 10 15 20 25 30 35 40 45
Time (min)
HR(beats∙min-1
)
Females
Males
* * * **
Figure 2. Mean (±SE) for systolic blood pressure
(SBP) during the CP and withdrawal phase WP
in females using oral contraceptives, and at
M1and M2 in males. * Main effect of time:
different to baseline (P < 0.05). ** Main effect for
time: different to 5 min (P < 0.05).
Figure 3. Mean (±SE) for diastolic blood
pressure (DBP) during the CP and WP in
females using oral contraceptives, and at M1 and
M2 in males. * Main effect of time: different to
baseline (P < 0.05).
Figure 4. Mean (±SE) for cardiac output (CO)
during the CP) and WP in females using oral
contraceptives, and at M1and M2 in males. A
phase by gender interaction was reported (P <
0.05).* Main effect of time: different to baseline
(P < 0.05). ** Main effect for time: different to 5
min (P < 0.05). *** Main effect for time: different
to 10 min (P < 0.05).
Figure 5. Mean (±SE) for heart rate (HR) during
the CP and WP in females using oral
contraceptives, and at M1 and M2 in males. A
phase by gender interaction was reported (P <
0.05). * Main effect of time: different to baseline
(P < 0.05).