Buscar

Treinamento de Força na Reabilitação Cardíaca

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Você viu 3, do total de 12 páginas

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Você viu 6, do total de 12 páginas

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Você viu 9, do total de 12 páginas

Faça como milhares de estudantes: teste grátis o Passei Direto

Esse e outros conteúdos desbloqueados

16 milhões de materiais de várias disciplinas

Impressão de materiais

Agora você pode testar o

Passei Direto grátis

Prévia do material em texto

Strength Training in Cardiac Rehab 1 
 Running Head: Strength Training in Cardiac Rehab 
 
 
 
 
 
 
Strength Training in Cardiac Rehabilitation 
Eric Coleman S.P.T. 
Wayne State University 
 
 
 
 
 
 
 
 
 
 
 
 
Strength Training in Cardiac Rehab 2 
 
ABSTRACT 
With each passing day new discoveries are made which have the potential to reshape 
clinical practice. As scientists and clinicians it is important to be aware of both, past 
evidence that has molded current clinical practice, and emerging bodies of evidence that 
will shape the future of our practice. Over the past two decades strength training has 
been virtualy non existent in cardiac rehabilitation. If strength training was implemented 
into a Cardiac Rehabilitation Program (CRP) it was always left until Phase III and in 
more Traditional programs, not at all. More recent scientific research may soon establish 
early phase II as the appropriate time to begin strength training. 
 
 
 
 
 
 
 
 
 
 
Strength Training in Cardiac Rehab 3 
 
Strength Training in Cardiac Rehabilitation 
 “Cardiac Rehabilitation has been defined as comprehensive long term programme 
which ideally includes, in addition to prescribed, supervised exercise training, medical 
evaluation, risk profiling, education and counseling, and coronary risk factor 
modification by pharmacological and nonpharmacological intervention” (Leon, 2000). 
The role of the Physical Therapist within the scope of Cardiac Rehabilitation is to provide 
appropriate exercise prescription to address physical impairments of the patient in order 
to facilitate return to as normal a lifestyle as possible. For decades Cardiac 
Rehabilitation Programs (CRP’s) have addressed the needs of their patient population 
using primarily aerobic conditioning to improve cardiorespiratory endurance (Verrill, 
Ribisl., 1996). Many patients involved in CRP’s have deficits in muscular strength 
secondary to bed rest, administration of corticosteroids, and premorbid state of 
deconditioning. Historically “ Resistance, or weightlifting training, was not 
recommended, most probably because of the acknowledged pressor response induced by 
sustained isometric contraction.” (McCartney et al, 1998). Due to the role of muscular 
strength in the performance of a various vocational and recreational activities, many 
Cardiac patients are likely to have functional limitations (Maiorana., 1997). In the role of 
a Physical Therapist it is important that the needs of the patient are recognized, as well as, 
options available to fill those needs. 
Strength Training in Cardiac Rehab 4 
Research 
Isometrics 
A study was performed by Atkins et al to examine the effects of isometric 
exercise as a stress test for left ventricular function. This research used forty-five cardiac 
patients of varying diagnosis and functional classes. Patients performed trials of 
isometric handgrip dynamometry at 25 and 50% of maximum voluntary contraction 
(MVC) for periods of 3-5 minutes and 30 seconds to 3 minutes respectively. Patients 
also performed aerobic exercise on a bicycle ergometer until reaching a symptom limited 
maximal load. Subjects were continuously monitored by electrocardiogram (ECG) 
during all trials. Results of this study showed higher systolic blood pressure, and greater 
incidence of arrhythmias during isometric exercise when compared with aerobic. The 
most significant difference was a high number of ventricular arrhythmias during 
isometric testing (Atkins et al., 1976). The major limitation of this research is that 
patients used in the study varied in functional classification, while data presented in the 
report does not identify whether or not patients in lower classes may have been more 
likely to experience adverse effects. 
 Another study examining the effects of isometric resistance was performed by 
Sagiv et al 1985. The objective of this research was to compare left ventricular responses 
to upright isometric resistance in normal versus coronary artery diseased (CAD) men. 
Subjects used in this study were 14 men with CAD having history of myocardial 
infarction (MI) and ten normal men with no reported cardiac history. The tasks to be 
performed were upright isometric handgrip and dead lift. Trials were performed at 30% 
MVC for 3 minutes. During trials each subjects heart rate (HR), Blood Pressure (BP), 
Strength Training in Cardiac Rehab 5 
left ventricular wall motion and left ventricular ejection fraction were monitored. The 
most significant finding in this study was the development of new wall motion 
abnormalities not seen at rest in CAD men, which researchers attributed to ischemia from 
increased rate pressure product or increasing dyskinesia in previously abnormal regions 
(Sagiv et al., 1985). A major limitation of this study is that nine of the fourteen subjects 
displayed wall motion abnormalities at rest, therefore, presence of abnormalities cannot 
be attributed to the testing (Sagiv et al, 1985) 
 Findings of research examining physiological effects of isometric resistance like 
that which is described above, are commonly cited to discourage strength training for 
cardiac patients. However, the examiners in both instances studied acute effects of single 
bouts of prolonged isometric contractions. This cannot be generalized to all forms of 
resistance training. Some researchers would argue that all forms of resistance training 
have an inherent isometric component. However, the duration of isometric contractions 
used in most of the trials is not indicative of that which would be required in CWT 
training programs. 
Circuit Weight Training 
 “Circuit weight training consists of performing a series of weight lifting exercises 
with moderate weight loads and frequent repetitions. Typically the subject moves to a 
station, performs the exercise, e.g. 30 sec and then moves to the next station to perform 
again” (Keleman et al., 1985). This method of resistance training utilizes short rest 
intervals between sets, thus maintaining increases in HR and has been proposed to 
facilitate increased strength as well as improved aerobic capacity. According to Verril 
and Ribisl, CWT either does not increased VO2 max or elicits only mild to moderate 
Strength Training in Cardiac Rehab 6 
increases (4-15%) with greater improvements being seen in less fit individuals (Verril et 
al, 1996). 
In a study comparing 20 subjects in traditional phase III cardiac rehab (aerobic 
exercise only) to 20 subjects participating in a combined program (CWT and aerobic). 
The control group performed a 10-minute warm-up, 20 minutes of walking or jogging at 
85% of maximum HR (based on treadmill test), and 20 minutes of recreational volleyball. 
The combined group performed the same warm-up and aerobic activity, but substituted 
two complete circuits of weight training using a ten-station circuit in place of recreational 
volleyball. Training for both groups occurred three times weekly for ten weeks. The 
CWT protocol required subjects to perform 10-15 repetitions per station at 40% of one 
repetition maximum (1 rm) in 30 sec at each station with 30 seconds of rest between 
stations. Results of this study show an average 24% increase in strength, 12% increase in 
total treadmill time for the combined group. No significant changes in either strength or 
endurance were noted for subjects in the control group. Radiotelemetry was used to 
monitor HR, and the presence of arrhythmias. No new arrhythmias were produced in 
either group (Keleman et al 1985). Case studies have been describedin which cardiac 
patients experience significant improvements in symptoms and/or function following 
relatively short bouts of resistance training (McCartney, 1998) 
Research initiating weight training with patients in phase II cardiac rehabilitation 
yielded results following data collection indicating that weight training was safe for low 
risk patients during phase II cardiac rehabilitation (Squires et al., 1991). The major 
limitation of this study is that experimenters did not control variance by establishing a 
uniform number of treatment sessions for participants in the study. Due to the large 
Strength Training in Cardiac Rehab 7 
variance in number of sessions for different participants individual results cannot be 
pooled and statistical power for this research is very low. 
 In a study of CWT in phase two cardiac rehab using subjects 6-16 weeks post- 
MI. Researchers found that Not only was CWT safe for these patients, but produced 
fewer adverse responses to exercise including: hypotension, hypertension, Angina, 
Arrhythmias, and ST segment depression. This study also compared combined protocols 
using three intensities of CWT to a control group using a more traditional model. All 
groups trained three times per week performing 40 minutes of walking or cycling, with 
the Combined groups performing an additional 15 minutes of CWT following aerobic 
activity. The CWT protocols for Combined groups are described as follows: Group 20; 
performed 20 repetitions at 20% of 1rm, Group 40 performed 10 repetitions at 40% of 
1rm, Group 60 performed seven repetitions at 60% of 1 rm. The amount of weight to be 
used was determined at the onset of the study and remained constant throughout the ten-
week training period. All three groups participating in the circuit weight training 
displayed significant increases in strength following the ten-week training period, while 
the control group showed no significant increase in strength. There was also a stepwise 
trend that suggests that the groups training at higher percentage of 1rm showed greater 
improvements, however, that data did not prove statistically significant. All four groups 
in this study showed significant increases in VO2 max, yet none proved to be 
significantly greater than any other group (Daub et al., 1996). Limitations of this study 
are: mean age of subjects was 49.3 years of age, CWT excluded lower body, 
Experimental groups had more training, and no protocol was assigned for progression of 
weight training. Age of greater than 61 years was one criteria for exclusion from this 
Strength Training in Cardiac Rehab 8 
study and the mean age of subjects at 49.3 makes it difficult to generalize this research to 
older cardiac patients. If CWT were likely to facilitate improvements in aerobic capacity 
as tested using a Bruce treadmill test, it would be beneficial to include the lower body in 
the CWT protocol. The experimental groups received 15 minutes more training per 
session, which may have skewed the results of this study in favor of the groups 
participating in CWT. The failure of this study to show significant differences in strength 
gained among the three CWT groups may be due to the lack of a protocol for progression 
of the strength training. Had specific instructions been given for CWT progression the 
trend that is evident in the data may have been more significant. 
Later research on CWT in phase II cardiac rehabilitation compared a middle aged 
group (mean age 48 +/_ 7) to an older group (mean age 68 +/_3). All subjects had 
suffered a recent MI (4-12 weeks) and had undergone angioplasty while hospitalized. 
Both groups in this study performed a Protocol of combined CWT with aerobic exercise. 
CWT was performed at 50% of MVC for ten repetitions; training was progressed using 
specific guidelines related to the Borg scale of perceived exertion. CWT sessions took 
place over an 11week period, 3 times weekly for 10-15 minutes per session. Aerobic 
training began 1 week prior to CWT and continued throughout the 11 week trial 
(Fragnoli-Munn et al., 1998) 
The results from this study reported no adverse reactions to training in either 
patient group. Both groups displayed significant increases in strength and maximal 
oxygen uptake post-training (Fragnoli-Munn et al., 1998) 
Stewart performed a study “To determine if weight training used during cardiac 
rehabilitation as soon as four weeks after myocardial infarction (MI) is safe, and if weight 
Strength Training in Cardiac Rehab 9 
training combined with aerobic exercise improves aerobic fitness and muscle strength 
more than aerobic exercise alone” (Stewart et al., 1998). This research used 23 male 
subjects who had experienced an uncomplicated MI as soon as 4 weeks, but not greater 
than 6 weeks previously. The control group performed aerobic exercise only, using a 
schwinn airdyne bicycle. Total training time for the control group was 30-35 minutes, 
consisting of a 5-minute warm-up, 20-25 minutes at target heart rate, and 5 minutes of 
cool down. The combined group also utilized the airdyne bicycle, performing a 5-minute 
warm up, followed by 8 minutes of cycling at target heart rate prior to completing 2 
circuits of a six station program. CWT was performed at 40% of 1rm with the goal of 
completing 10-15 repetitions in 30 sec. Subjects were allowed 30 seconds of rest 
between stations. Amount of weight lifted at each station was increased when subjects 
were able to complete 15 repetitions easily within 30 seconds. Both training groups 
performed exercise three times weekly for 10 weeks on nonconsecutive days. Duration 
of exercise sessions for the control and experimental group were equal (Stewart et al., 
1998). 
Results of this study showed a 14% increase in maximal oxygen uptake, 10% 
increase in exercise duration, 31% increase in leg strength, 20% increase in arm strength, 
and 23% increase in total strength for the combined group. The control group did not 
display statistically significant increases (8%) in VO2 max or exercise duration (Stewart 
et al., 1998). 
Future Research Considerations 
 Further research should be conducted to explore physiological effects of isometric 
training. The research previously cited explored only acute effects of single bouts of 
Strength Training in Cardiac Rehab 10 
prolonged isometric resistance. New research should be conducted to explore whether or 
not a training effect can be achieved using repeated isometric contractions (<30sec) over 
a ten-week training period. Would maximal Isometric strength improve and if so, would 
this increase result in a diminished hemodynamic response to isometric resistance and 
subsequent increase in patient safety? 
There are many variables to be considered when designing and implementing a 
program of CWT “Unless all of these variables are either controlled or manipulated as 
part of experimental design, it is not possible to accurately compare energy cost, evaluate 
hemodynamic responses between protocols, or assess the safety of different protocols for 
use with a cardiac population” (Degroot et al., 1998). More research using Combined 
CRP’s in phase II targeting specific populations and program parameters is necessary. 
Comparative analysis such as Number of circuits, repetitions, frequency of training, type 
of exercises included in CWT program should all be performed. 
Research has also suggested that patients that are the most deconditioned may 
display the greatest improvement following CWT or combined CRP’s. This is a direction 
that research should explore in order to determine at level of VO2 max would patients 
benefitthe most from Combined and or CWT CRP’s. 
Quality of life measures have been used in attempts to quantify effects of 
treatment on life following Cardiac care (Taylor et al., 1998). Attempts to implement this 
sort of measure with Cardiac Patients pre and post CWT may provide valuable 
information. 
Strength Training in Cardiac Rehab 11 
Summary 
Changes in the traditional model of Cardiac Rehabilitation have been slow. 
Research used in arguments against integrating resistance training into CRP’s, although 
valid, is not applicable to the topic of CWT. 
There are many possible adverse effects to isometric exercise for cardiac patients 
including: dangerous increases in end-diastolic pressure and end systolic volume of the 
left ventricle, decreased end-diastolic volume and ejection fraction, exacerbated wall 
motion abnormalities and dysrhythmias (McCartney, 1998) 
There is a growing body of research proving the safety and effectiveness of 
Combined CRP’s utilizing CWT and aerobics in early phase II for specific populations. 
Not only is this proven to be a safe and effective approach to achieve desired increases in 
maximal oxygen uptake, but also, increases in strength often necessary to facilitate 
optimal function. “The majority of CAD patients are senior citizens; several surveys 
have shown that the elderly are often excluded from exercise training in spite of 
reconditioning” (Perk et al., 2000). Whether strength training begins within the Physical 
Therapy outpatient setting during Phase II, or during Community based Phase III it is the 
duty of the Physical Therapist as a health care provider and educator to inform the patient 
of possible benefits and appropriate resources. The role of the Physical Therapist as an 
educator does not end with the patient, but extends to our peers, other health care 
professionals and into the community. 
 
Strength Training in Cardiac Rehab 12 
 
 
Bibliography 
 
 
(2001). "Recommendations for exercise training in chronic heart failure patients." Eur 
Heart J 22(2): 125-35. 
Atkins, J. M., O. A. Matthews, et al. (1976). "Incidence of arrhythmias induced by 
isometric and dynamic exercise." Br Heart J 38(5): 465-71. 
Daub, W. D., G. P. Knapik, et al. (1996). "Strength training early after myocardial 
infarction." J Cardiopulm Rehabil 16(2): 100-8. 
DeGroot, D. W., T. J. Quinn, et al. (1998). "Circuit weight training in cardiac patients: 
determining optimal workloads for safety and energy expenditure." J Cardiopulm 
Rehabil 18(2): 145-52. 
Fragnoli-Munn, K., P. D. Savage, et al. (1998). "Combined resistive-aerobic training in 
older patients with coronary artery disease early after myocardial infarction." J 
Cardiopulm Rehabil 18(6): 416-20. 
Keleman, M H., Stewart, K.J. "Circuit Weight Training A new Direction For Cardiac 
Rehabilitation." Sports Med 2: 385-388. 
Leon, A. S. (2000). "Exercise following myocardial infarction. Current 
recommendations." Sports Med 29(5): 301-11. 
Maiorana, A. J., T. G. Briffa, et al. (1997). "A controlled trial of circuit weight training 
on aerobic capacity and myocardial oxygen demand in men after coronary artery 
bypass surgery." J Cardiopulm Rehabil 17(4): 239-47. 
McCartney, N. (1998). "Role of resistance training in heart disease." Med Sci Sports 
Exerc 30(10 Suppl): S396-402. 
Perk, J. and G. Veress (2000). "Cardiac rehabilitation: applying exercise physiology in 
clinical practice." Eur J Appl Physiol 83(4 -5): 457-62. 
Sagiv, M., P. Hanson, et al. (1985). "Left ventricular responses to upright isometric 
handgrip and deadlift in men with coronary artery disease." Am J Cardiol 55(11): 
1298-302. 
Shephard, R. J. and G. J. Balady (1999). "Exercise as cardiovascular therapy." 
Circulation 99(7): 963-72. 
Squires, R.W., Muri, A.J., Anderson, L.J., Allison, T.G., Miller, T.D., Gau, G.T.(1991). 
"J Cardiopulm Rehabil 11: 360-364. 
Stewart, K. J., L. D. McFarland, et al. (1998). "Safety and efficacy of weight training 
soon after acute myocardial infarction." J Cardiopulm Rehabil 18(1): 37-44. 
Taylor, R., B. Kirby, et al. (1998). "The assessment of recovery in patients after 
myocardial infarction using three generic quality-of-life measures." J Cardiopulm 
Rehabil 18(2): 139-44. 
Verrill, D. E. and P. M. Ribisl (1996). "Resistive exercise training in cardiac 
rehabilitation. An update." Sports Med 21(5): 347-83. 
 
	ABSTRACT
	Research
	Isometrics
	Circuit Weight Training
	Future Research Considerations
	Summary

Outros materiais