Recently, I was flying home after having taught a continuing education course for the Academy, titled “Exercise Training Guidelines for Individuals With Cancer.” As I raced along at 35 000 feet, I asked myself, “What key points, outside of the basics of exercise testing and prescription, would I like my audience to take home with them”? Following is a partial answer to that question.
- A. Consider providing each patient who comes to you for care with a heart rate monitor with a chest strap at the time of initial evaluation. I make this recommendation for several reasons. First, consider it a safety issue. Increasing heart rate normally accompanies an increase in exertional demand (exercise) and does so in a manner that is directly proportional to a progressive increase in exertional demand.1 A failure of heart rate to do so appropriately suggests that the mechanisms controlling heart rate are dysfunctional and your patient is at risk for an adverse event. Placing heart rate monitors on patients allows the clinician [and the wearer] to easily and quickly access real-time heart rate information, information that might suggest cardiac dysfunction, a signal for discontinuing an exercise session, and possibly a referral back to the patient's oncologist for further evaluation.
- Cancer survivors are at increased risk for autonomic dysfunction, a comorbidity that can compromise their ability to appropriately respond to increasing exertional demand.2 Knowledge of an apparent mismatch between exercise intensity and heart rate can be a safety issue and an exercise prescription issue. Combining real-time monitoring of heart rate during exercise with visual inspection for the presence of signs and symptoms of cardiovascular distress and patient-reported rating of perceived exertion provides a robust perspective of patient response to exercise intensity and provides assurances that a heart rate–based exercise prescription is both safe, efficacious, and physiologically sound.3
- Most aerobic exercise intensities are predicated on an estimated maximum heart rate and are prescribed within defined target heart rate ranges that, if achieved for sufficient duration, will improve conditioning status.1 A patient wearing a heart rate monitor while aerobically exercising allows a clinician and the patient to quickly and easily determine whether the target heart rate contained in the exercise prescription is being achieved or whether the exercise prescription is inappropriate either in general or for that particular session. Knowing that the patient is exercising within his or her target heart rate range helps ensure that reconditioning goals will be met and treatment plans are being followed.
- Finally, clinicians often rely on the heart rate numbers provided by a pulse oximeter. While providing 2 pieces of physiologic information, these devices have, in my experience, proven to be generally unreliable from an operational perspective, that is, they often work only intermittently during exercise. It is discouraging for a clinician to be in the midst of an exercise test only to have the pulse oximeter fail, limiting the collection of important functional and physiological data.
- B. Deconditioning is not limited in the cancer survivor to aerobic deconditioning and will, quite likely, include strength deficits, a problem that can adversely affect a survivor's physical functional capacity.4 As such, an exercise prescription must include goals and interventions to improve both aerobic conditioning and strength. We all learned how to perform manual muscle testing (MMT) in school, focusing on proper hand placement and joint stabilization. Despite the quality of our techniques, results from MMT remain qualitative at best and provide challenges in translating the results into quantifiable exercise prescriptions and strengthening goals. New devices such as hand-held myometers that quantify the force produced during a manual muscle test have been shown to be reliable, valid, and increasingly available.5 Results from these devices are sensitive to testing techniques, particularly to instrument placement, so testing protocols must be standardized within a clinic and across institutions. The 1-repetition maximum test is also safe and reliable for use in the oncology population, but its use may be limited by the availability of appropriate testing equipment.6 Other strength testing tools are available, such as an isokinetic machine, but these devices have significant practical limitations in a clinical setting. Knowing or accurately estimating a patient's strength allows for documenting quantifiable assessments of strength and generating personalized exercise prescriptions.
- C. The average age of a patient in this country at the time of a cancer diagnosis is 56 years, and 75% of survivors are older than 65 years. These facts graphically point out that treating survivors often requires treating comorbidities associated with the disease and its treatment as well as those associated with older age. Oncologic physical therapists are often geriatric physical therapists by default, and they must recognize this reality. Because of their age, many cancer survivors experience sarcopenia, a progressive, age-associated loss of muscle strength, which, in turn, diminishes their physical functional capacity. Sarcopenia contributes to frailty, a physical phenotype characterized by the presence of 3 or more phenotypes (unintentional weight loss, weakness, poor endurance, slowness, and inactivity).7 The presence of frailty has been associated with an earlier occurrence of disability, premature aging, compromised surgical outcomes, and reduced responsiveness to chemotherapy.8 The deficits that characterize frailty are clearly identifiable and treatable by physical therapists. While these losses are not completely reversible, participation in an exercise training program can ameliorate this progressive decline in strength and aerobic capacity, further supporting my argument that the evaluation and treatment of most cancer survivors should include aerobic and resistance exercise testing and the development of a multimodal exercise prescription. Diagnosing frailty, even if it is not contained in a medical prescription for physical therapy, can identify deficits that should be treated, thus allowing for expanding the services offered to these patients. Gait speed is considered to be the best, single-item screening tool for assessing for frailty.
- D. Available guidelines to assist clinicians in the development of exercise programs for cancer survivors generally fail to incorporate exercise guidelines specific for the older individuals. Because of this oversight, clinicians must know and understand these guidelines so that they can safely and effectively provide exercise-based services to the older cancer survivor. For example, the American College of Sports Medicine (ACSM) and the American Heart Association have provided recommendations for physical activity in older adults.9 Some of the recommendations for this group are interesting. For example, the authors strongly recommend the use of the 0- to 10-point rating of perceived exertion scale rather than heart rate to describe exercise intensity, with a 5- to 6-point rating equaling moderate exertion. When there is concern that an individual might not understand exercise intensity, a period of supervised exercise is recommended so as to help the individual learn the desired level of exertional effort. Sets of resistance exercises should include 10 to 15 repetitions rather the 8 to 12 repetitions recommended for adults. Specific recommendations call for the engagement in at least 10 minutes of flexibility activities per exercise session and these activities be performed on all days that aerobic and muscle-strengthening activities are performed, which suggests that flexibility activities should be performed as many as 5 times per week. Perhaps, most significantly, these authors remind us that older individuals commonly have comorbid conditions requiring specific exercise interventions that may be superimposed on general reconditioning needs. As such, an optimal exercise prescription may need to reflect a blending of general public health recommendations, that is, ACSM guidelines1 for reconditioning with an impairment and disease-specific prescription.
- E. Every physical therapist knows that changing the fitness status of a patient requires that individual to be sufficiently challenged physiologically to bring about adaptations to reduce the relative demand of physical and functional activity. Defining that challenge is the underlying premise of the FITT model, that is, exercise Frequency, Intensity, Time (duration), and Type.1 Exercise prescriptions or exercise-based treatment plans must clearly quantify these components of an exercise prescription and describe how the exercise program will be progressed over the duration of the treatment plan. These characteristics of an exercise session must be documented in daily notes, if for no other reason than to inform the next therapist or assistant who treats the patient what had been done previously and what steps need to be taken to ensure progression of the treatment plan. In 2012, Campbell et al10 reviewed randomized controlled trials of exercise interventions used to study women with a diagnosis of breast cancer for the completeness of their reporting on the FITT specifics of tested exercise protocols. None of the 29 articles reviewed reported all FITT components of their exercise prescription or adherence to the prescribed exercise program. If researchers do not fully document exercise specifics and adherence, I wonder what is occurring in the clinics regarding completeness and accuracy of documentation. Incomplete documentation can easily compromise the effectiveness of an exercise prescription and possibly demonstrate that a treatment plan is not being implemented. After all, if a treatment plan calls for a patient walking on a treadmill at a target heart rate range of 45% to 55% of heart rate reserve for 25 minutes, shouldn't the note demonstrate that this intervention did indeed occur. The Template for Intervention Description and Replication (TIDieR) checklist prompts authors to describe interventions in adequate detail to allow their replication. This checklist includes the minimum recommended items for describing an intervention in a publication. This journal requires the checklist be included in the submission of intervention manuscripts as do most biomedical journals.11
Enough of my ramblings!!!!
G. Stephen Morris, PT, PhD, FACSM
1. American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription. 10th ed. Philadelphia, PA: Wolters Kluwer; 2017.
2. Lakoski SG, Jones LW, Krone RJ, et al Autonomic dysfunction in early breast cancer: incidence, clinical importance, and underlying mechanisms. Am Heart J. 2015;170:231–241.
3. Morris GS, Smith WA, Hudson MH, et al Chronotropic incompetence in cancer survivors. Abstract presented at: the Annual meeting of the American College of Sports Medicine; May 2013; Indianapolis, IN.
4. Reid KF, Fielding RA. Skeletal muscle power: a critical determinant of physical functioning in older adults. Exerc Sport Sci Rev. 2012;40:4–12.
5. Arnold CM, Warkentin KD, Chilibeck PD, et al The reliability and validity of handheld dynamometry for the measurement of lower-extremity muscle strength in older adults. J Strength Cond Res. 2010;24:815–824.
6. Rogers BH, Brown JC, Gater DR, et al Association between maximal bench press strength and isometric handgrip strength among breast cancer survivors. Arch Phys Med Rehabil. 2017;98:264–269.
7. Fried LP, Tangen CM, Walston J, et al Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci. 2001;56:M146–M157.
8. Handforth C, Clegg A, Young C, et al The prevalence and outcomes of frailty in older cancer patients: a systematic review. Ann Oncol. 2015;26:1091–1101.
9. Nelson ME, Rejeski WJ, Blair SN, et al Physical activity and public health in older adults: recommendation from the American College of Sports Medicine and the American Heart Association. Med Sci Sports Exerc. 2007;39:1435–1445.
10. Campbell KL, Neil SE, Winters-Stone KM. Review of exercise studies in breast cancer survivors: attention to principles of exercise training. Br J Sports Med. 2012;46:909–916.
11. Hoffmann T, Glasziou P, Boutron I, et al Better reporting of interventions: Template for Intervention Description and Replication (TIDieR) checklist and guide. BMJ. 2014;348:g1687.