Cardiovascular responses to abdominal exercises in females between 35 and 45 years of age.S Rao, B Bellare
Dept of Physiotherapy, LTMMC, Bombay, Maharashtra.
Cardiovascular responses viz. systolic and diastolic blood pressure and pulse rate were evaluated in 21 females following muscular exercises for abdominal wall strengthening. Trunk curl exercise and leg raising exercise were selected for this purpose. A significant increase in systolic and diastolic blood pressure and pulse rate was observed following these exercises. These raised values returned to pretreatment value 6 min later after supine lying. These changes indicate that the need for strict supervision during sessions, especially for the hypertensive patients.
Keywords: Abdominal Muscles, Adult, Age Factors, Blood Pressure, physiology,Exercise, Female, Human, Middle Age, Pulse, physiology,
Abdominal exercises form an important part of treatment plans designed by orthopaedic and general surgeons, gynaecologists-obstetricians and physiotherapists. These exercises are also included in exercise programmes aimed at physical fitness for the population at large.
Anterior abdominal wall muscles along with the posterior trunk muscles and the spine, are important in supporting the body weight. Weakness of these muscles predisposes to low back pain and poor posture.
The middle-aged female population reveal a reduction in abdominal muscle power due to multiple pregnancies and a lack of regular exercise and therefore, are often advised muscular exercises for abdominal muscle strengthening. Since review of the' literature revealed little on the effect of these exercises on the cardiovascular system, the present study was carried out to evaluate cardiovascular responses to muscular exercises.
Twenty-one normotensive, non-diabetic females between 35 and 45 years of age (mean 38.6 yrs) participated in the study. They had no orthopaedic, gynaecological or gastrointestinal complaints at the time of the study. Subjects were not active participants in any exercise programm6 and had no abdominal muscle training previously.
Basal parameters were recorded after 10 minutes of rest in the supine position. They included: 1. abdominal muscle power grade (Kendall and McCreary). 2. systolic and diastolic blood pressure (SBP and DBP) and 3. pulse rate (PR). Trunk curl exercise and bilateral leg raising exercise were demonstrated. [Figure:1] and [Figure:2]. ach exercise was asked to be performed in a set of 10 repetitions. Parameters were recorded before exercise, after exercise and at two minute intervals for a recovery period of six minutes, in the supine position. A rest period of 30 minutes was allowed between the two exercises.
The basal abdominal muscle power grade was fair. The grade 'fair' (or 50%) of abdominal muscle power denotes the ability of these muscles to elevate and lower the head and shoulders off the horizontal at an angle of 450 or ability to maintain the low back flat while holding both lower limbs vertically above the hips at 900 flexion and knees extended.
[Table - 1] displays the changes observed after the trunk-curl exercise.
[Table - 2] displays the changes observed after the leg raising exercise.
Both the exercises showed a significant rise in SBP, DBP and PR. At the end of six minutes, these raised values returned to pre-exercise levels.
Subjective complaints included breathlessness and palpitations during the first exercise. Fatigue in the lower limb muscles were reported during the second exercise by four subjects.
The exercises evaluated in our study are routinely used for abdominal muscle strengthening.
The trunk curl exercise activates the rectus abdominis and the external oblique muscles in the range of upto 45? upright position with respect to the horizontal. The return to the horizontal is also the responsibility of these muscles, working eccentrically. The ability to hold the low back flat during bilateral leg raising exercise is dependent upon the activity of all the abdominal muscles.
Both exercises were performed in a set of 10 repetitions in order to obtain an adequate magnitude of stress on the circulatory system. As the muscle power of all our subjects was 50% or fair-grade, the exercises could be assumed to have a proportionate stress on the CVS in all subjects.
In the supine position, the heart maintained a resting cardiac output at a basal heart rate. Exercises in this position resulted in increase in the venous return reflected as the rise in cardiac output. This resulted rise in SBP and PR linearly,,.
The rise in DBP following both the exercises could be due to a rise in intra-abdominal tension compressing the blood vessels in the abdomen thus raising the 2 peripheral resistance.
The second exercise showed a higher magnitude of change as compared to the first. This was due to greater muscle activity involved in the second exercise. The type of muscle work is also different in the two exercises. The trunk-curl exercise involved concentric type of work to raise the trunk and eccentric work in lowering the trunk to the horizontal. The leg raising exercise involves more static muscle work. Both the exercises showed a non-specific recovery to basal levels at the end of 6 minutes supine lying.
These exercises cause a significant change in cardiovascular parameters and hence require monitoring. Hypertensives or patients with cardiovascular disorders should be advised these exercises with caution. Reduced repetition rates and longer rest periods are advisable. Unsupervised sessions should have rest periods of at least 6 minutes between exercises and at the end of sessions too.
[Table - 1], [Table - 2]