Bimal Raj, Rijo Oommen Iype, Tulasiram Bommasamudram* and Shifra Fernandes
Department of Exercise and Sports Science, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India
*Corresponding Author: Tulasiram Bommasamudram, Department of Exercise and Sports Science, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India.
Received: May 24, 2021; Published: June 10, 2021
Post-exercise hypotension (PEH) is a condition wherein there is a drop in blood pressure (BP) after a simple exercise bout. PEH could be used as an effective strategy to regulate blood pressure at rest, particularly among people with hypertension. This literature review attempts to investigate the significance of PEH induced via aerobic and resistance training in hypertensive, pre-hypertensive, and normotensive individuals. The articles chosen for this review addressed active adult and the older population who were either normotensive, pre-hypertensive, or hypertensive and engaged in aerobic exercise or resistance exercise. Since the research studies have used different prescriptions and protocols for the aerobic and resistance training, which leads to certain disagreements about the intensity and duration of the workouts to be prescribed. Aerobic training appears to encourage a greater and longer decrease in BP rates as compared to resistance training. Also, high intensity or moderate intensity training both can reduce the risk of cardiometabolic disorder.
Keywords: Blood Pressure; Post-Exercise Hypotension; Aerobic Training; Strength Training; Resistance Training; Endurance Training
BP: Blood Pressure; PEH: Post-Exercise Hypotension; HIIT: High-Intensity Interval Training; HIIE: High-Intensity Interval Exercise; MCE: Moderate-Intensity Continuous Exercise; HRV: Heart Rate Variability; RM: Repetition Maximum
One of the major risk factors for cardiovascular disease is hypertension. Nearly 45 percent of deaths from coronary artery disease and 51 percent of deaths from strokes can be related to the presence of hypertension [1]. Even after knowing the health risks of physical inactivity, it appears to be a struggle for many people to engage in regular exercise/physical activity. A spike in the rate of urbanization across the globe has been associated with changes in human behavior and has thus lead to a greater section of the society, adopting a sedentary lifestyle. Daily exercise could be considered as a non-medical aid for BP management. Engaging in any form of physical activity has proven to help reduce BP in pre-hypertensive and hypertensive populations. Besides lowering blood pressure, physical activity also helps to maintain cardiovascular health, as well as reduce mortality rate [2-4]. Prolonged and regular exercise has been shown to significantly lower blood pressure amongst various populations [5,6]. Research also found that, in terms of pre-exercise blood pressure (BP), a session of physical exercises would reduce BP. This phenomenon known as post-exercise hypotension mainly seen in persons with hypertension [2,3,7-9].
PEH is characterized by a decrease in systolic or diastolic blood pressure following at least 30 minutes of physical exercise [2,7]. 30 to 45 minutes of moderate-intensity exercise may result in a reduction of 5 - 10 mmHg in young normotensive individuals, on the other hand, higher differences are observed in hypertensive individuals [2]. The drop in blood pressure following exercise was attributed to either a decline in cardiac performance or a drop in systemic vascular resistance. Such modifications are affected by improvements in autonomic cardiac regulation and sympathetic vasomotor behavior that are triggered during the exercise bout [10].
PEH has been observed with different forms of exercise, such as walking, running, cycling, swimming, and resistance exercise [11]. Short duration low-intensity exercise efficiently stimulates PEH, whereas prolonged duration and High-intensity interval training (HIIT) has the potential to further lower blood pressure and prolong the duration of PEH. HIIT workouts have demonstrated a longer PEH period as compared to sub-maximum constant-load exercise [12].
The main objective of this literature review is to provide a consolidated understanding concerning the influence of PEH with aerobic and resistance exercise in normotensive, pre-hypertensive, and hypertensive individuals.
The search was conducted via online databases such as PubMed, PLOS ONE, Springer, Google Scholar and Scopus repositories for literature review, with keywords “Post-exercise hypotension”, “blood pressure response”, “aerobic exercise” “resistance exercise”. All data that was obtained was published between January 2014 to February 2020. The inclusion criteria for this review were studies that addressed active adult or older populations who were either normotensive, pre-hypertensive, or hypertensive and engaged in either aerobic exercise or resistance exercise. The results obtained from the search were then selected or rejected based on the aforementioned criteria. Only research work that was reported in English was considered for this review.
Exercise is a beneficial non- medical supplement to improve the regulation of blood pressure. It has been seen in a variety of populations that both acute bout as well as chronic exercise, significantly lower BP [2]. Research has shown a clear positive correlation between the reduction in blood pressure and the magnitude of PEH during aerobic exercise [3,8]. The prescription of aerobic exercise plays a significant role in decreasing coronary artery diseases and mortality rates. It has also been emphasized, that this form of workout is a silver norm for improving cardiovascular and respiratory health and many reports have found that poor cardio-respiratory health is a marker of age-related death [13,14].
PEH occurs after exercise, which is performed either in the morning or in the evening [15]. Studies suggest that the benefits of lowering systolic blood pressure are more noticeable after a morning workout while considering circadian rhythm variations. This is associated with a decrease in cardiac index, owing to a lesser heart rate and sympathovagal balance. Additionally, a mild vasodilatory response was noticed after exercising in the morning [16].
A research was performed to distinguish the severity of PEH in hypertensive individuals undertaking High-intensity interval exercise (HIIE) and equate it with moderate-intensity continuous exercise (MCE). It was observed that MCE encourages PEH which is strongly prescribed for people with hypertension. Whereas in the sedentary population, the performed HIIE indicates some clinical and physiological benefits for post-exercise hypotension. However, one hour after the exercise sessions, the HIIE developed a greater magnitude of reduction in systolic and mean arterial pressure than MCE [14].
Another study explored the impact of short-term HIIT on PEH in young women who were overweight or obese, following the training and detraining phase. In order to know their maximum aerobic capacity (VO2max), the subjects were asked to perform an incremental exercise test until exhaustion on the treadmill. The results of the VO2max test were used to determine the running speed, in order to achieve 90 - 95% HR max. while performing HIIT. The training intervention consisted of six sessions. Participants were asked to refrain from working out for 2 weeks and then report to the clinic for re-tests. Consequently, the study revealed the correlation of six HIIT sessions with clinically relevant PEH responses. However, two weeks of detraining reversed the effects of training, in a manner that allowed SBP to return to resting values. Although DBP was not influenced much by detraining, it stayed consistently weak and the magnitude stayed equivalent. To retain the acquired benefits for a longer period of time, it is necessary to establish and maintain an exercise routine [17]. Therefore participating in HIIT or Moderate intensity exercise helps to reduce blood lipids, decreases the percentage of body fat, and also improves cardiovascular fitness [18].
Aquatic exercise has several benefits, especially for people suffering from cardiovascular diseases. It is widely recommended for the elderly population, considering it could provide a variety of health benefits. Owing to the buoyancy principle, bodyweight could be lowered by about 90%, and thus reduces the risk of several musculoskeletal injuries as compared to land-based exercises, especially for overweight and obese individuals [19]. Even though there are only a few studies that evaluated the response of ambulatory BP to aqua training and it shows a higher reduction in the response to PEH and was able to maintain that for a prolonged period of time. I addition to PEH, water-based training is mainly recommended for the older population as it reduces the load and mechanical stress on the musculoskeletal system [20,21]. Aquatic exercises often tend to have the additional advantage of minimizing pain [20]. Such forms of training have been incorporated in rehabilitative and therapeutic interventions, that further aid with the improvement of cardiovascular health and muscular fitness, mainly for adults and older adults, having limited functional movements [21,22].
One study explored the effect of aquatic training on PEH in physically active, older women with hypertension. The training session included eighteen consecutive group exercises, each lasting two minutes and thirty seconds on average. There were four upper and four lower body exercises, and ten exercises that involved a combination of both upper and lower limb exercises. The control session/group had a forty-five minutes session without any exercise, and the participants could sit or stand during that duration. This study showed that the total systolic blood pressure after water-based exercises could reduce by 5 mmHg in the 21 hours after exercise when compared with the CONTROL session [23].
Resistance exercise and post-exercise hypotensionResistance exercise commonly known as strength training is advised for the cure and management of cardiac illness as a non-pharmacological therapy. Aerobic training generally facilitates a larger and prolonged decrease in PEH magnitude than resistance exercises. There is no fixed protocol for strength training that could contribute to stronger decreases in blood pressure levels in persons with hypertension [22]. Only a few trials have been conducted to verify the significance of strength training on PEH as compared to aerobic training. It has been suggested that regular strength exercise could lower the systolic and diastolic blood pressure by 3.9 mmHg and 3.2 mmHg respectively [6]. PEH was documented both for normotensive and hypertensive individuals. There is thus some proof that strength training could be effective in prolonging the reduction of BP at rest as per the guidelines of ACSM. Therefore, resistance exercise can be advised for the care of hypertensive individuals [22].
In 2015, a group of researchers tried to determine the effect of resistance training, performed with various load intensities, on BP and heart rate variability (HRV) in trained individuals. The subjects were healthy males with a minimum of six months of strength training experience. With each session, the subjects performed 3 sets of 8 to 10 repetitions at different intensities, with 2 min rest intervals between sets. BP and HRV were monitored before each exercise session and one hour after each session. The results showed that training at 70% 1RM (Repetition Maximum) was preferred to prolong the period of PEH, compared to 60% or 80% 1RM training sessions [24].
Cavalcante., et al. analyzed the findings of various intensities of resistance exercise on PEH in hypertensive older women. The participants were asked to perform a 1RM test to assess experimental loads between 40 percent and 80 percent. The protocol demanded each participant to perform 3 sets of a few exercises as per the investigator's instructions in a single set. A 90 seconds rest was allowed between each set. During rest and at 5, 10, 15, 30 and 45 minutes of exercise and after 60 minutes of exercise, the systolic and diastolic blood pressure was measured and recorded. This study showed that these older women with hypertension exhibit PEH regardless of exercise intensities, without any cardiopulmonary fatigue throughout the exercise program [25].
The effect of resistance exercise performed at varying workout orders and rest intervals on BP and HRV has been investigated. The participants were males with a minimum weight training background of 12 months. The exercises were carried out as per the protocol and directions are given by the investigator. Once the 15 RM load had been completed for one exercise, a 10-min break was given just before going to test for the next one. All exercises were carried out on the same day. The participants were told randomly to perform the exercise in two separate A and B sets. The training order in sequence A, begins from large to small muscle groups, with either 40-sec or 90-sec intervals between sets. The training order in sequence B began with small to large groups of muscles with the same rest intervals. The BP and HRV were recorded 10 minutes before the exercise began and after each of the four strength training protocols at each interval of 10 minutes for 1 hour. It was thus concluded that a 90-sec rest break between sets and exercise is recommended while doing upper body resistance training to stimulate the PEH reaction with SBP. The 40-second rest breaks between sets and exercises exerted greater cardiovascular stress, and thus may be contraindicated while dealing with individuals with cardiovascular diseases [26].
Aerobic and Resistance training typically encourages cardiovascular benefits for people of different age groups, intending to control blood pressure. Different forms of physical training, such as HIIT and moderate-intensity training help lower blood lipids, reduces the amount of body fat percentage, and also improves cardiovascular health. Most of the studies indicate that aerobic activity performed at 50% to 60% of VO2 max for 30 to 45 minutes reflects a reduction in SBP or DBP resulting in PEH. Overall, these studies indicate that the relatively short period of HIIT or moderate-intensity exercise training can reduce cardio-metabolic risk factors in young people who had previously been sedentary or obese. Aquatic training is also considered good adjunctive therapy for controlling BP, providing great efficacy and reducing the risk of musculoskeletal injuries as well as lowering cardiovascular risk, especially in older individuals. Training at 70% 1RM is considered to be more beneficial to prolong the benefits of PEH, as compared to training at 60% or 80% 1RM. A 90-sec rest period between sets and exercises is recommended to encourage a PEH reaction to SBP while performing upper body strength training. However, when it comes to the safety of individuals, the intensity of exercise should be 50% 1RM. The rest between each set and exercises should be at least for one minute, especially with the major muscle groups. Besides, longer exercise bouts that lead to fatigue should be avoided as it may lead to greater increases in BP. We can thus conclude that there is a beneficial correlation between the frequency of PEH, and the reduction in BP following aerobic and resistance training. Aerobic exercise can be much more effective in lowering blood pressure and aerobic exercise also reduces liver fat.
Aerobic and Resistance training typically encourages cardiovascular benefits for people of different age groups, intending to control blood pressure. Different forms of physical training, such as HIIT and moderate-intensity training help lower blood lipids, reduces the amount of body fat percentage, and also improves cardiovascular health. Most of the studies indicate that aerobic activity performed at 50% to 60% of VO2 max for 30 to 45 minutes reflects a reduction in SBP or DBP resulting in PEH. Overall, these studies indicate that the relatively short period of HIIT or moderate-intensity exercise training can reduce cardio-metabolic risk factors in young people who had previously been sedentary or obese. Aquatic training is also considered good adjunctive therapy for controlling BP, providing great efficacy and reducing the risk of musculoskeletal injuries as well as lowering cardiovascular risk, especially in older individuals. Training at 70% 1RM is considered to be more beneficial to prolong the benefits of PEH, as compared to training at 60% or 80% 1RM. A 90-sec rest period between sets and exercises is recommended to encourage a PEH reaction to SBP while performing upper body strength training. However, when it comes to the safety of individuals, the intensity of exercise should be 50% 1RM. The rest between each set and exercises should be at least for one minute, especially with the major muscle groups. Besides, longer exercise bouts that lead to fatigue should be avoided as it may lead to greater increases in BP. We can thus conclude that there is a beneficial correlation between the frequency of PEH, and the reduction in BP following aerobic and resistance training. Aerobic exercise can be much more effective in lowering blood pressure and aerobic exercise also reduces liver fat.
We declare no conflict of interest.
Citation: Tulasiram Bommasamudram., et al. “Post-Exercise Hypotension - A Narrative Review".Acta Scientific Orthopaedics 4.7 (2021): 25-29.
Copyright: © 2021 Tulasiram Bommasamudram., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.