Cardiovascular Exercise: An Evidence-Based Approach

Hypertension is a significant public health concern, in which its reach extends internationally (RamBihariLal Shrivastava, Saurabh Shrivastava, & Ramasamy, 2014). Considered the most common cardiovascular disease risk factor, more than 23 million cardiovascular deaths are estimated to occur by the year 2030, due to hypertension (RamBihariLal Shrivastava et al., 2014). Complications related to hypertension include atherosclerosis, heart failure, coronary artery damage, poor quality of life, and even death (RamBihariLal Shrivastava et al., 2014). Considering the widespread reach and complications of hypertension, especially in middle-aged (i.e., 40-64 years) individuals, development of preventative interventions is paramount. One constituent of a preventative hypertension intervention protocol (PHIP) includes cardiovascular exercise, which is supported by the American College of Sports Medicine (ACSM); regular physical activity lowers blood pressure, improves lipoprotein profiles, C-reactive protein, insulin sensitivity, as well as other biomarkers (Garber et al., 2011). However, it is essential to implement a PHIP that is predicated on an evidence-based approach, to protect the welfare of the individual, and maximize outcome measures (i.e., lowered blood pressure, improved blood lipid profiles). The following sections will cover approaches that the author implements with middle-aged clientele, as a means of understanding and appreciating the intricacies of a safe and effective periodized PHIP.

During an initial assessment and consultation, the author has the client read and fill out a medical questionnaire. Following the medical questionnaire, the client reads and fills out a physical activity readiness questionnaire, provided by the Canadian Society for Exercise Physiology (CSEP) (CSEP, 2015). Such steps help determine if there are any contraindications that may inhibit the safe participation in an exercise program. In addition, blood pressure is taken as a secondary measure to determine if hypertension exists. Hypertension is indicated if blood pressure is at, or above, 140-159/90-99 (American Heart Association, 2015). If the client reaches or surpasses the aforementioned systolic and diastolic readings, the client must see their family physician, and provide written approval before beginning a periodized exercise program. The following will review concepts and approaches of a periodized PHIP using cardiovascular exercise.

After a client has been screened and approved to embark on a periodized cardiovascular program (PCP), development of a cardiovascular regime commences. Garber et al. (2011) noted that the ACSM has outlined an approach, which manipulates exercise variables thereby inducing adaptive changes in human physiology; F.I.T.T. (frequency, intensity, time, type). The aforementioned guideline applies to both strength training, and cardiovascular exercise. Park et al. (2014) suggested that 150 minutes (duration) of moderate to vigorous activity (intensity) be achieved, preferably each day (frequency) of the week through any modality such as walking, biking, hiking (type) etc.… The following sections will explore each constituent of F.I.T.T. more deeply, as it applies to a periodized PHIP specific to the author’s clientele.

F.I.T.T. (Intensity)

Moderate intensity can be viewed as the rate of perceived exertion (RPE) while performing cardiovascular exercise (Garber et al., 2011). Moderate activity is correlated to an RPE of 12-13, considered fairly light to somewhat hard. Vigorous activity can be defined as an RPE rating of 14-17, also considered somewhat hard to very hard (Garber et al., 2011). Since the author’s clients are generally middle-aged and deconditioned, exercise intensity will be targeted at moderate intensity and gradually progress towards vigorous intensity, as recommended by the ACSM (ACSM, 2015). The RPE scale, although not considered a primary mode of evaluating the degree of intensity, still has a moderate to strong validity as it relates to other biomarkers (i.e., %VO_2max, %HR, blood lactate concentrations) (Garber et al., 2011). Thus, for simplicity, RPE will be used to determine moderate and vigorous intensities for the periodized PIHP.

F.I.T.T. (Frequency and Time)

Total duration of moderately intense exercise is recommended as 30 minutes a day, 5 days per week, culminating to 150 minutes per week (Garber et al., 2011). Vigorously intense exercise is recommended to last approximately 20 minutes a day, 3 or more days per week, of less than 75 minutes of total duration per week (Garber et al., 2011). Thus, the author’s PHIP will be predicated on the aforementioned duration recommendations as the client transitions from moderate to vigorous intensity.

F.I.T.T. (Type)

The author’s clientele are often recovering from motor vehicle accidents (MVAs); choosing a type of exercise modality that circumvents irritating soft tissue damage sustained from an MVA remains paramount. Ground reaction forces from running can rise as high as 200% of bodyweight, which has been associated with shin splints, bruises, strains, and stress fractures (Quigley & Richards, 1996). Thus, for the author’s clientele, stationary bikes, or recumbent bikes, reduce ground reaction forces while still stimulating the cardiovascular system. Having considered the F.I.T.T. principle, its constituents, and application to the author’s middle-aged clientele, the following sections will provide an 8-week periodized cardiovascular program to help prevent/reduce hypertension.

WEEK: #1 and #2 (Performed Three Days- Monday, Wednesday, Friday)

Prior to any form of exercise, the author instructs all clients on how to perform a sufficient warm-up. Warm-ups begin with self-myofascial release (SMR) on all large muscle groups for approximately 10 repetitions per muscle. SMR has been shown to loosen muscles, and reduce tension, without losses in force production (Sullivan, Silvey, Button, & Behm, 2013). Following SMR is static stretching; evidence of Mohr, Long, and Goad (2014) suggested that combined modalities (i.e., SMR and static stretching) maximized muscle tissue length changes more than one modality in isolation. Stretches are held for 30-60 seconds, as recommended by Garber et al. (2011) to maximize tissue length changes for older adults. After SMR and static stretching, additional specific warm-up on a recumbent bike is provided, as a means of familiarizing the client with the machine. The client will perform approximately 5 minutes of exercise on the bike that matches an RPE of 11 or less considered light (ACSM, 2015). Weeks 1 and 2 will have the client engage in 3 x 25 minute cardiovascular exercise at an RPE of approximately 13, as a means of introducing some volume (i.e., 75 minutes total per week) for 2 weeks while maintaining a low intensity.

WEEK: #3 (Performed Three Days- Monday, Wednesday, Friday)

Week 3 represents the manipulation of intensity. Although weeks 1 and 2 represents approximately 50% of target volume (i.e. 75 minutes instead of 150 minutes), it should be noted that although the author is providing a cardiovascular program as a preventative hypertension protocol, resistance training is always included as a secondary means of improving biomarkers, in addition to nutritional coaching (both of which are beyond the scope of the author’s paper). Thus, target cardiovascular volumes are modulated to accommodate other constituents of the client’s program.

Week 3 is designed to introduce the client to interval training. High intensity interval training (HIIT) can be defined as a time-efficient training method for improving cardiorespiratory and metabolic function (Buchheit & Laursen, 2013). Interval training can be manipulated to place emphasis on each metabolic pathway (i.e., phospagen, anaerobic glycolytic, and oxidative). However, caution must be exuded as each system has a particular neuromuscular effect. For example, HIIT protocols that target the phospagen pathway (i.e., intervals which last approximately 10 seconds and >90% of velocity to elicit 100% VO_2max) also place a high demand on force production, thereby exhausting muscles (Buchheit & Laursen, 2013). Since the author’s clients are also engaging in strength training on other days during the week, implementing HIIT, which engages the phospagen pathway, may place excessive stress on the neuromuscular system. Such an approach would likely affect the middle-aged client’s ability to recover between sessions. Thus, engaging the fast glycolysis / oxidative system would place the least neuromuscular load on the body, while improving oxidative capacity and cardiovascular function (Baechle & Earle, 2000).

The fast glycolysis / oxidative pathway is stimulated with a work interval lasting approximately 1 to 3 minutes, followed by 3 times the amount of time in rest (i.e. a 1-minute work interval requires up to 3 minutes rest) (Baechle & Earle, 2000). Such an approach is considered at least moderately difficult or greater, aligning with the recommendation for middle-aged individuals embarking on a cardiovascular program (Garber et al., 2011). Week 3 will begin with approximately 4 x 1-minute work intervals, with rest intervals up to 3 minutes after each working set. Total time involved (i.e., work and rest intervals) will amount to approximately 16 minutes. The following sections will explore the final progressions to reach target volumes over the remaining 5 weeks.

WEEK: #4 (Performed Three Days- Monday, Wednesday, Friday)

WEEK: #5 (Performed Three Days- Monday, Wednesday, Friday)

WEEK: #6 (Performed Three Days- Monday, Wednesday, Friday)

WEEK: #7 (Performed Three Days- Monday, Wednesday, Friday)

WEEK: #8 (Performed Three Days- Monday, Wednesday, Friday)

The aforementioned sections noted that moderate to vigorous activity is defined as up to 75 minutes of cardiovascular exercise per week (Garber et al., 2011). After week 4, one work interval is added every 2 weeks (i.e. weeks 5 and 6 both have 5 work interval sets, while weeks 7 and 8 have 6 work interval sets). Volume is slowly increased so as to abide by the recommendation of Garber et al. (2011) to gradually manipulate one or more constituents of the F.I.T.T. principle over time. Thus, at the conclusion of the 8^th week, the author’s client would have reached the target time (i.e., approximately 75 minutes) of moderate to vigorous activity (i.e., 6 minutes of intervals + 18 minutes of rest x 3 days per week = 72 minutes).

Hypertension is prevalent and widespread, associated with several determinants and risk factors (RamBihariLal Shrivastava et al., 2014). Physical inactivity, among many other risk factors, plays a role in exacerbating hypertension. Conversely, physical activity, which includes regular engagement in cardiovascular exercise, has been shown to support favorable changes in biomarkers (lowered resting blood pressure, improved lipid profiles) related to hypertension and cardiovascular disease (Garber et al., 2011). However, it is paramount that pre-hypertensive and hypertensive individuals are provided with exercise programs steeped in, and predicated upon, evidence-based research. Pragmatically developing and implementing exercise programs, with a scrupulous approach, will help guarantee that the interests and safety of the client remain central. Finally, such a method will help the client attenuate hypertension, maximize outcome measures, and improve quality of life.

References

ACSM (2015). ACSM current comment; Perceived exertion. Retrieved https://www.acsm.org/docs/current-comments/perceivedexertion.pdf

American Heart Association (2015). Understanding blood pressure readings. Retrieved from http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/AboutHighBloodPressure/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp

Baechle, T.R., & Earle, R.W. (2000). Essentials of strength and conditioning (2^nd Ed.): National strength and conditioning association. Champaign, IL: Human Kinetics.

Buchheit, M., & Laursen, P.B. (2013). High-intensity interval training, solutions to the programming puzzle. Sports Medicine, 43(10), 927-954.

CSEP (2015). PAR-Q and you. Retrieved from http://www.csep.ca/english/view.asp?x=698

Garber, C.E., Blissmer, B., Deschenes, M.R., Frankklin, B.A., Lamonte, M.J., Lee, I.M., … Swain, D.P. (2011). American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. American College of Sports Medicine, 43(7), 1344-1359.

Mohr, A.R., Long, B.C., & Goad, C.L. (2014). Foam rolling and static stretching on passive hip flexion range of motion. Journal of Sport Rehabilitation. doi: http://dx.doi.org/10.1123/jsr.2013-0025

MRM Kinetics (2015). Questionnaire. Retrieved from http://www.mrmkinetics.com/downloads

Park, J.H., Miyashita, M., Takahashi, M., Kawanishi, N., Hayashida, H., Kim, H.S., … Nakamura, Y. (2014). Low-volume program improves cardiovascular-related health in older adults. Journal of Sports Science and Medicine, 13(3), 624-631.

Quigley, E.J., & Richards, J. (1996). The effects of cycling on running mechanics. Journal of Applied Biomechanics, 12(4), 470-479.

RamBihariLal Shrivastava, S., Saurabh Shrivastava, P., & Ramasamy, J. (2014). The determinants and scope of public health interventions to tackle the global problem of hypertension. International Journal of Preventative Medicine, 5(7), 807-812.

Sullivan, K.M., Silvey, D.B.J., Button, D.C., & Behm, D.G. (2013). Roller-massager application to the hamstrings increases sit-and-reach range of motion within five to ten seconds without performance impairments. International Journal of Sports Physical Therapy, 8(3), 228-229.

-Michael McIsaac