Hypertension: Guide to Exercise Testing & Prescription

Hypertension is an idiopathic disease categorized as having either an elevated systolic or diastolic blood pressure value.  It is defined as having a resting systolic blood pressure greater than or equal to 140 mmHg or a diastolic blood pressure higher than 90 mmHg; normal readings should be less than 120/80 mmHg.  It is a disease of all ages and is known as the “silent killer” because it can lead to stroke, myocardial infraction, coronary death, or kidney disease. 

The arterial blood pressure equation is: arterial blood flow per minute or cardiac output times total peripheral resistance to flow.  It is expressed as: Q x TPR and blood pressure reflects the amount of pressure on the blood vessel walls that blood exerts. Cardiac output is affected by stroke volume and heart rate; total peripheral resistance is affected by arteriolar radius and blood thickness. (Haslam et. al, 2011) Arteries that accumulate fatty deposits on the vessel walls decrease in size and have consistent resistance to peripheral blood flow that results in greater pressure readings.  This pressure on the arteries overtime leads to less elasticity in the arterial walls that contain elastic and muscle fibers.  (McArdle et. al, 2007)

Blood pressure is usually measured at the brachial artery and systolic is the first sound of the pressure of turbulent blood flow through the cuff.  It estimates the amount of work the heart is doing and the amount of pressure the arterial blood flow is exerting against the walls during ventricular systole.  Diastolic blood pressure is the forth karatoff sound and represents the blood flow from the artererioles to the capillaries without turbulence.  This is the relaxation phase and it represents total peripheral resistance. 

The combination of lifestyle modification and pharmacological treatment is important for treating hypertension and reducing heart disease, the leading cause of death in the US.  In fact, lifestyle modification is required if systolic blood pressure is between 120-139 mmHg or diastolic blood pressure is between 80 and 89 mmHg, pre-hypertensive ranges.

Endurance exercise is important for decreasing the risk of hypertension because it decreases norepinephrine concentration in blood plasma, and may improve renal function (fluid balance) and sodium retention.  It also decreases sympathetic nervous system activation and reduces hypertrophy, which impacts total peripheral resistance and decreases metabolic syndrome factors.  (Biggerstaff, 2011)   

Exercise Testing Guide for Hypertension

Medical evaluation is necessary before beginning any sort of exercise testing and all medications need to be reviewed by physician as well.  Participants need to be risk stratified and high intensity exercise should be avoided unless they are under medical supervision. Strategies to minimize risk would be to breathe, don’t take the set to fatigue, and do not grip too tightly when lifting. (Hofford, 2010)

Guidelines to follow when exercise testing are:

• Relative contraindication: Resting BP >200 /110 mmHg
• Test termination: drop in SBP (greater than 10 mmHg) with an increase in workload and/or an increase in SBP >250 mmHg or DBP >115 mmHg
• During exercise the range of SBP and DBP should be: <220 / <105 mmHg
• Antihypertensive medication like Beta-blockers, vasodilators, and Ca+ channel blockers may blunt heart rate or blood pressure and lead to post-exercise hypotension, <90/60 mmHg.  Therefore, a cool-down is imperative to prevent problems such as fainting.

Exercise Tests for Hypertensive participants

• Aerobic: Submaximal YMCA test
• Flexibility: Sit and Reach test
• Body composition: Waist circumference, skin fold measurements, or DEXA scan 
• Strength: Submaximal leg press and bench press
• Muscular endurance: Push-up and Curl-up test

Exercise Prescription for Hypertension

Emphasis for the exercise prescription should be on aerobic exercise and moderate intense resistance exercise should be supplemented.  Aerobic exercise will lead to lower resting blood pressure measurements and ultimately lower the risk for hypertension.     

Aerobic Training

• Goal: 700-2,000 kcal/week
• Frequency: 3-7 d/week, preferably all days of the week
• Intensity: 40-70 % VO2R or HRR; moderate-intensity
• Time: 30-60 minutes per day of continuous or intermittent (10 min bouts)
• Type: swimming, walking, jogging, and cycling

Resistance Exercise 

• Frequency: 2-3 d/week
• Intensity: 60-80% 1-RM; 1 set, 10-15 repetitions,
• Type: 8-10 exercises that focus on the major muscle groups & exercises that do not spike blood pressure are important.  Avoid the Valsalva maneuver during resistance exercise.

Flexibility

• Static and dynamic stretching
• At least 10 min of stretching exercises performed after the warm-up or cool-down phase and progress to yoga

Warm up & Cool down

• At least 5 to 10 minutes of low (<40% VO2R) to moderate (40% to <60% VO2R) intensity
• Goal: increase body temperature for warm up and reduce post-exercise hypotension for cool-down 

References

Biggerstaff, Kyle D. (2011, November). Hyperlipidemia & Hypertension.  Exercise Evaluation

and Prescription. Lecture conducted from Texas Woman’s University, Denton.

Ehrman, Gordon, Visich & Keteyian, eds. Clinical Exercise Physiology, 2nd ed. Champaign, IL:

Human Kinetics, 2009.

Thompson, WR, ed. ACSM’s Guidelines for Exerise Testing and Prescription, 8th ed.

Philadelphia, PA: Wolters Kluwer/Lippincott Williams & Wilkins 2010.

McArdle, Katch, F., & Katech, V. Exercise Physiology Energy, Nutrition, & Human

Performance, 6th ed. Philadelphia, PA: Wolters Kluwer/Lippincott Williams & Wilkins

2007.

Haslam, B; Gordhandas, A; Ricciardi, C; Heldt, T; Verghese, G. Relating Noninvasive Cardiac

Output and Total Peripheral Resistance Estimates to Physical Activity in an Ambulatory

Setting (2011). Computational Physiology and Clinical Inference Group in the Research

Laboratory of Electronics.