Cycling CME

A unique CME learning experience for Physicians, PA-C's, and other Medical Providers who love to bike

Active CME:  Combining Continuing Medical Education (CME) and Bicycle Touring for the Healthcare Provider

Filtering by Category: promoting exercise

Exercise and Father Time

A Lifetime of Exercise Slows Down Father Time

With significant interest in the mature athlete and aging in general, I found recent articles by Pollock and Duggal et al, in the journal The Aging Cellquite interesting. As we are aware, aging is associated with many physical and cognitive changes. Common physical problems may include immune, hormonal and muscle changes. An example is sarcopenia, the loss of skeletal muscle as we age, which has concomitant loss of muscle mass as well as changes in contractile function.

This research group from the UK has evaluated greater than 125 active male and female cyclists aged 55-79 year old in regards to muscle findings and physiological functions. This group would be considered active as the men were able to cycle 100km in under 6.5 hours and the women 60km in under 5.5 hours.

They compared these adults to a group that did not participate in regular physical activity ages 20 to 80. The study showed that regular exercise diminished the loss of muscle and strength with age. In addition, they had lower body fat and total cholesterol and the men’s testosterone remained higher than the non-exercisers. In addition, the cyclist’s immune system appeared to have less aging as their thymus, which makes our T cells, continued to make T cells similar to the younger population. In the second study, they evaluated vastus lateralis muscle biopsy samples from a subset of these cyclists (n=90). They concluded that exercise was able to mitigate most of the effects of inactivity and aging across the age groups studied.

Very interesting research on the powerful effects of a lifetime of exercise. Be sure to have an active day.

Cycling CME

References:

Ross D. Pollock, Katie A. O'Brien, Lorna J. Daniels, Kathrine B. Nielsen, Anthea Rowlerson, Niharika A. Duggal, Norman R. Lazarus, Janet M. Lord, Andrew Philp, Stephen D. R. Harridge. Properties of the vastus lateralis muscle in relation to age and physiological function in master cyclists aged 55-79 years. Aging Cell, 2018; e12735 DOI: 10.1111/acel.12735

Duggal et al. Major features of Immunesenescence, including Thymic atrophy, are ameliorated by high levels of physical activity in adulthood. Aging Cell, 2018

Exercise and Hypertension

One of my colleagues at the Colorado Mesa University Monfort Family Human Performance lab is Carmine Grieco, PhD, an exercise physiologist. It has been interesting to hear Carmine’s perspective on Exercise is Medicine, as he has been involved at the research level and is very interested in the effects of exercise on chronic disease. Carmine and I wrote a four-part series for Personal Training Quarterly (PTQ) discussing the impact of exercise on chronic disease. For that series, we started with the impact of exercise on Type 2 Diabetes, exercise and the brain and now discussed exercise and hypertension - that article is below. Clearly, exercise should play a critical role in the overall treatment plan for patients. (Please note before reading: Patients with hypertension, diabetes and any other chronic disease or condition should first discuss a change in exercise levels or habits with their personal medical provider. This is informational only.)


Exercise and Hypertension

Carmine Grieco, PhD, CSCS

Michael Reeder, D.O.

Grieco CR and Reeder MT. (2016) Exercise and Hypertension - Part 3 Exercise and the Brain. Personal Training Quarterly, 4(3).

Preface

This article is the 3rd in a 4-part series which will explore the impact of exercise on a variety of diseases and conditions. As fitness professionals, we understand the positive effect exercise has on health and human performance. Despite the efficacy of exercise as both a preventive and treatment for so many diseases and conditions, standard medical interventions (notably medications) remain the “go to” medical option for most individuals. In fact, recent estimates by the National Center for Health Statistics suggest that nearly 50% of the U.S. population have used a prescription drug within the last 30 days (1). Therefore, the aim of this article series is to provide a context for understanding the efficacy of exercise as adjunct therapy and compare this to commonly prescribed treatments.

Hypertension, more commonly known as high blood pressure or the “silent killer”, is pervasive in the United States and represents a major public health problem. It is the most prevalent and preventable cardiovascular risk factor and one of the costliest to our health care system (2). The Centers for Disease Control and Prevention (CDC) estimate that nearly one out of every three adults in the United States have hypertension. African Americans are substantially more likely to have hypertension, with rates at 45.7 and 43%, for females and males, respectively (3). Importantly though, only about 80% of hypertensive adults are aware of their condition and, of those, only 48% achieve adequate control (4).

Hypertension is defined as having a resting systolic blood pressure (SBP) ≥140 mm Hg and/or a diastolic blood pressure (DBP) ≥90 mm Hg and/or taking antihypertensive medication (5). Hypertension is further classified according to severity, as follows (6):

Normal Blood Pressure

<120 mm Hg <80 mm Hg

Prehypertension

120-139 mm Hg - 80-89 mm Hg

Stage I Hypertension

140-159 mm Hg - 90-99 mm Hg

Stage II Hypertension

>160 mm Hg - >100 mm Hg

Hypertensive Crisis

>180 mm Hg - >110 mm Hg

High blood pressure (BP) levels are associated with a diversity of negative health outcomes, including an increased risk of stroke (7) and cardiovascular disease (8).). However, high BP is also a significant risk factor for renal disease, peripheral artery disease, heart failure, reductions in brain volume and Alzheimer’s disease (10,11). High BP, as a primary contributing cause, has led to approximately 360,000 deaths in the U.S. annually, or nearly 1,000 per day (2,3).

While the primary treatment for hypertension relies on medication, there are several non-pharmacological strategies, such as weight loss, sodium restriction, biofeedback and guided breathing exercises (9). However, of the non-pharmacological treatments, exercise (both aerobic and dynamic resistance) has the strongest evidence of efficacy (9). Regular exercise is an essential modifiable determinant of hypertension. “Therefore, strategies to increase physical activity are needed to decrease hypertension’s burden.”(12).

Aerobic ExerciseLifestyle interventions are important in treating hypertension as they have few side effects, are low cost and improve other cardiovascular (CVD) risk factors. Regular exercise has been shown to decrease arterial stiffness, and improve BP in hypertensive patients, especially aerobic exercise (13,14). Aerobic exercise has been shown to be effective in both prevention and treatment of hypertension by lowering BP and decreasing the progression from prehypertension to hypertension (15,16). Meta-analyses looking at the effects of exercise on BP conclude that aerobic exercise lowers both SBP and DBP 4-7mmHG (15,17), a decline which is similar to the decrease noted with the first-line anti-hypertensive medications.

The normal immediate response to aerobic exercise is a mild increase in SBP with no change or a slight decrease in DBP from decreased peripheral vascular resistance (19). The effects of regular exercise that contribute to this decrease in BP include the following: decrease in heart rate, decrease in systemic vascular resistance, increase in arterial compliance, and decrease in sympathetic input and increase in nitric oxide availability (16). Conversely an abnormal BP response during aerobic exercise would be a significant drop in SBP or failure of SBP to increase with increasing load (5).

Aerobic exercise exerts both an acute and chronic effect on BP. Acutely, a powerful physiological effect of aerobic exercise is post exercise hypotension (PEH). With PEH, the exerciser experiences an immediate decrease in BP of 5-7 mmHg with exercise bouts lasting 10 – 60 min at intensities from 40 to 100% of maximum oxygen consumption (17). Multiple studies have shown this decrease in BP may last as long as 24 hours. (20,21). This exercise-mediated reduction in BP is especially helpful during the day when BP is typically the most elevated (15). The chronic changes from regular exercise include reduced resting BP and decreased arterial stiffness

Aerobic exercise prescription should be individualized using the FITT principle (frequency, intensity, time and type) The level of medical screening prior to the exercise prescription will depend on the intensity of the exercises planned as well as the patients overall cardiovascular risk. Patients with other cardiovascular risk factors and/or stage 2 hypertension need more intensive screening prior to moderate-intensity (40-60% VO2max, 3-6 METS or walking at a moderate pace) exercise but not for light activity (<40% VO2max, MET < 3 or a slow walk). Absolute contraindications include recent myocardial infarction, heart block, heart failure and other recent cardiovascular events (23).

Frequency: The majority of professional medical societies, such as the American Heart Association (9), now recommend exercise on most if not every day of the week, which is important given the impact of the PEH phenomenon

Intensity: published guidelines all recommend adults with hypertension engage in moderate-intensity exercise (40-60% of VO2max or heart rate reserve) (9,15,24). Interestingly, some evidence also supports high-intensity interval training (HIIT) as an exercise modality. HIIT consists of periods of brief, high-intensity aerobic exercise separated by recovery periods. Several studies have shown the benefit of HIIT over continuous moderate-intensity exercise and the impact on CV risk factors, including hypertension (25,26). However, more recent studies have urged caution until further research has been completed (17,24,27).

Time: The general consensus is that at least 30 minutes a day with at least 150 minutes per week of aerobic exercise is appropriate for hypertensive patients. Research has suggested that exercise can be accumulated in a single bout or several accumulated episodes among adults with hypertension and still be effective in reducing BP (14). For exercise adherence, short bouts of aerobic exercise during the day may be an important strategy for hypertensive patients (17).

Type: many beneficial aerobic exercise modes are available: walking, running, swimming and biking. One important factor in selecting the specific type is exercise adherence.

Resistance Training and Hypertension

Normal BP response to exercise differs between aerobic and resistance training. While aerobic training elicits an intensity-dependent increase in SBP and a negligible effect on DBP, a normal response to dynamic resistance training can significantly increase both SBP and DBP. Moreover, those with hypertension may experience greater increases in SBP during exercise than normotensive individuals (28).

One study compared BP response to resistance exercise between normotensive and hypertensive individuals (28). The authors compared low- (three sets at 40% 1RM to exhaustion, with 45s rest between sets) and high-intensity (three sets at 80% 1RM, with 90s rest between sets) exercise, using seated knee extension, on intra-arterial pressure, during work and rest periods (28). Both normotensive and hypertensive individuals experienced substantial increases during low- and high-intensity training, but the hypertensive group was significantly higher with both low--intensity (SBP 227 vs. 179 mmHg) and high-intensity programs (SBP 215 vs. 176 mmHg). Moreover, while the normotensive group’s SBP returned to baseline values during the rest period of low-intensity exercise, the hypertensive group remained elevated. Interestingly, the greatest increase in BP for both groups occurred during the low-intensity exercise, likely a product of maximal effort with minimal rest between sets.

Currently, substantial evidence links aerobic training with both acute and chronic reductions in BP. However, evidence supporting resistance training as a therapeutic modality is not as robust as that for aerobic training. One major reason may be relative dearth of studies on resistance training for as a treatment for hypertensive populations (29). Nevertheless, the American College of Sports Medicine’s (ACSM) Position Stand on Exercise and Hypertension recommends resistance training as “an important component of a well-rounded exercise program” for the treatment of hypertension (15). However, the ACSM recommends aerobic exercise as the primary modality, with resistance training to “serve as an adjunct” modality (15). Likewise, the American Heart Association’s (AHA) Scientific Statement on alternative approaches to lowering BP recommends resistance training, stating, “The overall evidence suggests that dynamic resistance exercise can lower arterial BP by a modest degree.” The AHA cites the relative lack of large scale studies and goes on to conclude, “it is conceivable that resistance exercise may merit even stronger recommendations in the future.” (9).

A recent meta-analysis by MacDonald et al. helps to illustrate this issue (30). Using data from 71 interventions (in 64 published studies) the authors found a relatively modest reduction in BP (2-3 mmHg) attributed to moderate-intensity resistance training. There was, however, a notable difference in effect when accounting for study population. Studies using hypertensive populations saw a substantially larger reduction in SBP and DBP than studies with normotensive populations (6/5 vs. 0/1 mmHg), indicating hypertensive populations may benefit more from exercise training than normotensive populations.

The ACSM as well as the AHA recommend resistance training for adults with hypertension. Current exercise guidelines for resistance training, from the ACSM, include (5):

Frequency: 2-3x/wk.

Intensity: 60-70% of 1RM (may progress to 80%). Older individuals or novice lifters should begin with 40-50% of 1RM

Time: 2-4 sets of 8-12 reps for major muscle groups

Type: Resistance machines, free weights and/or body weight exercises

While more research into the independent effect of resistance training on BP is warranted, particularly in hypertensive populations, clearly this form of training is efficacious.

Pharmacological Treatment of Hypertension

Practice guidelines established by the Eighth Joint National Committee (JNC8) recommend pharmacological treatment of high BP in adults <60 years begin when SBP ≥140 mm Hg and/or DBP ≥90 mm Hg (for adults >60 years the threshold of SBP is 150 mm Hg) (31). Lifestyle interventions (exercise, dietary change, weight loss, smoking cessation, etc.) are first-line treatments and should continue throughout the treatment plan. Four classes of medications are used for initial treatment of hypertension: thiazide-type diuretic, calcium channel blocker (CCB), angiotensin-converting enzyme inhibitor (ACEI), or angiotensin receptor blocker (ARB). The initial treatment strategy recommends beginning with monotherapy (i.e. one drug) and progressing to combination therapy (multiple drugs), as necessary (31).

Effectiveness of antihypertensive drug therapy is similar across all four drug classes. For example, Bronsert et al. (32), in a meta-analysis comparing the effectiveness of antihypertensive drugs, stated, “There were small, clinically insignificant differences in BP reductions between the monotherapy classes.” Another meta-analysis, which compared the effectiveness of antihypertensive drugs in prevention of cardiovascular disease, concluded, “We find limited evidence of important differences between the various drug-classes” (33). These conclusions are in agreement with current JNC8 recommendations (31).

While it is beyond the scope of this paper to evaluate the myriad combinations of antihypertensive drugs and their combined effect on BP reduction, we present the following as a point of comparison to evaluate the effectiveness of drug therapy in relation to exercise therapy as a form of treatment for hypertension. A recent meta-analysis found a risk-adjusted average reduction in SBP of 13.6 and DBP of 7.9 mm Hg, while using drug monotherapy (32). Combination therapy (i.e. using more than one drug), as either fixed-dose combination (FDC; combining two active agents into a single pill) or free-equivalent combination (FEC; prescribing two or more active agents) performed slightly better, resulting in a risk-adjusted reduction in SBP of 17.3 and 12.0 mm Hg, respectively, with the risk-adjusted reduction in DBP of 10.1 and 6.0 mm Hg, respectively (Bronsert et al., 2013). (This paper is not an evaluation of medication treatment; please talk with your physician if you have any questions.)

Conclusion

Hypertension is a major public health concern, affecting nearly one out of every three adults in the U.S. (3). Reductions in BP are strongly associated with a decrease in vascular disease risk. In fact, Lewington et al. estimated that a SBP reduction of only 10 mmHg or a DBP reduction of 5 mmHg would result in 40% lower risk of death from stroke and 30% lower risk of death from ischemic heart disease (35). Indeed, even a modest reduction in BP translates into a clinically meaningful risk reduction in vascular events, such as stroke and ischemic heart disease (15,29).

Lifestyle modification, including exercise, is important for both preventing and treating hypertension. More recent guidelines for treating hypertension have increased emphasis on lifestyle factors, such as exercise. Exercise, particularly aerobic exercise, compares favorably to antihypertensive drug therapy, reducing BP by 5-7 mmHg. While further research into the effect of resistance training on BP is necessary, especially in hypertensive populations, recent work suggests that this form of training is efficacious and safe (23). Current guidelines from the ACSM provide a framework for fitness professionals to create an individualized exercise prescription. Exercise training should be an essential component of treatment recommendations for the hypertensive client/patient. As fitness professionals, it is important to educate and encourage clients with hypertension on the importance of exercise in their overall health.

References

Mozzafarian D, Benjamin EJ, Go AS, et al. Heart Disease and Stroke Statistics-2015 Update: a report from the American Heart Association. Circulation. e29-322, 2015.

1. Centers for Disease Control and Prevention. High Blood Pressure Facts. https://www.cdc.gov/bloodpressure/facts.htm
Accessed on 21 April, 2017.

2. Roger VL, Go AS, Lloyd-Jones DM, Benjamin EJ, et cl. Heart disease and stroke statistics—2012 update: A report from the American Heart Association. Circulation125(1): e2-e220, 2012.

3. American College of Sports Medicine. ACSM’s Guidelines for Exercise Testing and Prescription (10thed.). Lippincott, Williams & Wilkins: Philadelphia, PA; 2018.

4. American Heart Association. Understanding blood pressure readings.
http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/KnowYourNumbers/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp#.WTrM0mjytPY
Accessed on 09 June, 2017.

5. Sacco RL, Benjamin EJ, Broderick JP, Dyken M, Easton JD, Feinberg WM, Goldstein LB, Gorelick PB, Howard G, Kittner SJ, Manolio TA, Whisnant JP, and Wolf PA. Risk Factors. Stroke28(7): 1507-1517, 1997.

6. Kannel WB. Framingham study insights into hypertensive risk of cardiovascular disease. Hypertension Research18(3): 181-196, 1995.

7. Brook RD, Appel LJ, Rubenfire M, et al. Beyond medications and diet: Alternative approaches to lowering blood pressure. Hypertension61(6): 1360-1383, 2013.

8. Rahimi K, Emdin CA, and MacMahon S. The epidemiology of blood pressure and its worldwide management. Circulation Research116(6): 925-936, 2015.

9. Beauchet O, Celle S, Roche F, Bartha R, Montero-Odasso M, Allali G, and Annweiler C. Blood pressure levels and brain volume reduction: A systematic review and meta-analysis. Journal of Hypertension31(8): 1502-1516, 2013.

10. Egan BM, Li J, Hutchison FN, Ferdinand KC. Hypertension in the United States, 1999 to 2012: Progress toward Healthy People 2020 goals. Circulation130:1692-9, 2014.

11. Pal S, Radavelli-Bagatini S, Ho S. Potential benefits of exercise on blood pressure and vascular function. Journal of the American Society of Hypertension7(6):494-506, 2013.

12. Pescatello LS, MacDonald HV, Ash GI, et al. Assessing the existing professional exercise recommendations for hypertension: a review and recommendations for further research priorities. Mayo Clinic Proceedings90:801-812, 2015.

13. Pescatello LS, Franklin BA, Fagard R, Farquhar WB, Kelley GA, Ray CA, American College of Sports Medicine. American College of Sports Medicine Position Stand. Exercise and hypertension. Medicine and Science in Sports and Exercise36(3): 533-553, 2004.

14. Sharman JE, La Gerche A, Coombes JS. Exercise and cardiovascular risk in patients with hypertension. American Journal of Hypertension28(2):147-158, 2015.

15. Pescatello LS, MacDonald HV, Lamberti L, Johnson BJ. Exercise for hypertension: A prescription update integrating existing recommendations with emerging research. Current Hypertension Reports17: 87, 2015.

16. Whelton SP, Chin A, Xin X, He J. Effect of aerobic exercise on blood pressure: a met-analysis of randomized, controlled trials. Annuals of Internal Medicine136:493-503, 2002.

17. Mcardle WD, Katch FI and Katch VL. Essentials of Exercise Physiology (4thed.). Lippincott, Williams & Wilkins: Baltimore, MD; 2011.

18. Quinn TJ. Twenty-four hour, ambulatory blood pressure responses following acute exercise: Impact of exercise intensity. Journal of Hypertension14:547-53, 2002.

19. Pescatello LS and Kulikowich JM. The aftereffects of dynamic exercise on ambulatory blood pressure. Medicine of Science and Sports and Exercise33:1855-61, 2001.

20. Agerwal SK. Cardiovascular benefits of exercise. International Journal of General Medicine5: 541-545, 2012.

21. Ghadieh AS and Saab B. Evidence for exercise training in the management of hypertension in adults. Canadian Family Physician61: 233-240, 2015.

22. Millar PJ, Goodman JM. Exercise as medicine: Role in the management of primary hypertension. Applied Physiology and Nutrition Metabolism39:856-858, 2014.

23. Eicher JD, Maresh CM, Tsongalis GJ. The additive blood pressure lowering effect of exercise intensity on post-exercise hypotension. American Heart Journal160:513-520, 2010.

24. Molmen-Hansen HE, Stolen T, Tjonaa AE, et al. Aerobic interval training reduces blood pressure and improves myocardial function in hypertensive patients. European Journal Preventative Cardiology19:151-60, 2012.

25. Holloway TM, Bloemberg D, daSilva ML, et al. High intensity interval and endurance training have opposing effects on markers of heart failure and cardiac remodeling in hypertensive rats. PLoS One10: e0121138, 2015.

26. de Souza Nery S, Gomides RS, da Silva GV, de Moraes Foriaz CL, Mion D Jr., and Tinucci T. Intra-arterial blood pressure response in hypertensive subjects during low- and high-intensity resistance exercise. Clinics65(3): 271-277, 2010.

27. Cornelissen VA, Fagard RH, Coeckelberghs E, and Vanhees L. Impact of resistance training on blood pressure and other cardiovascular risk factors: A meta-analysis of randomized, controlled trials. Hypertension58(5): 950-958, 2011.

28. MacDonald HV, Johnson BT, Huedo-Medina TB, Livingston J, Forsyth KC, Kraemer WJ, Farinatti PT, and Pescatello LS. Dynamic resistance training as stand-alone antihypertensive lifestyle therapy: A meta-analysis. Journal of the American Heart Association5(10), 2016.

29. James PA, Oparil S, Carter BL, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA311(5): 507-520, 2014.

30. Bronsert MR, Henderson WG, Valuck R, Hosokawa P, and Hammermeister K. Comparative effectiveness of antihypertensive therapeutic classes and treatment strategies in initiation of therapy in primary care patients: A Distributed Ambulatory Research in Therapeutics Network (DARTNet) Study. Journal of the American Board of Family Medicine26(5): 529-538, 2013.

31. Fretheim A, Odgaard-Jensen J, Brørs O, Madsen S, Njølstad I Norheim OF, Svilaas A, Kristiansen IS, Thürmer H, and Flottorp S. Comparative effectiveness of antihypertensive medication for primary prevention of cardiovascular disease: Systematic review and multiple treatments meta-analysis. BMC Medicine10:33, 2012.

32. Lewington S, Clarke S, Qizilbash N, Peto R, Collins R, Prospective Studies Collaboration. Age-specific relevance of usual blood pressure to vascular mortality: A meta-analysis of individual data for one million adults in 61 prospective studies. Lancet360(9349): 1903-1913, 2002.

33. National Center for Health Statistics. Health, United States, 2015: With special feature on racial and ethnic health disparities. Hyattsville, MD. Retrieved 2016 from http://www.cdc.gov/nchs/data/hus/hus15.pdf#079.

34.