Updated August 7, 2006

For why to exercise, read the page you are at now.
For how to exercise, see this page.

Exercise and Heart Failure
Introduction

Exercising will improve your quality of life and lower your risk of death. How much exercise you should do depends on your situation. If you want to ask your doctor how you should exercise, here are some questions to ask.:

  1. For aerobic exercises like walking, find out:
  2. For resistance exercises like using weights, find out:

The best single exercise you can do is walk. A motorized treadmill makes this much easier. Many CHFers can also do a weight training program. This prevents deconditioning. Your doctor may prescribe a supervised aerobic exercise plan called "cardiac rehab." If so, check first that your health insurance covers this, because it isn't cheap. Before you start exercising, your doctor may order a CPX (Vo2max) test to measure your ability to exercise.

 
 

Muscle Fiber Types 

Skeletal muscle is muscle like your arm and leg muscles - muscles you control and use to do work. These are made up of "fibers." You have 2 kinds of basic skeletal muscle fibers:

Type 1 Fibers - slow-twitch fibers
Type 1 fibers have low power but good endurance - they can be used quite awhile before tiring. You use slow-twitch fibers during prolonged activity like walking. Type 1 fibers are also used for maintaining posture. Think distance runners.
Type 2 Fibers - fast-twitch fibers
These come in two flavors: Type 2A and Type 2B. Type 2A fibers are a mix between Type 1 and Type 2B. You use type 2A fibers during activities requiring both strength and endurance. Type 2B fibers generate a lot of power very fast, but only for a short time. These fibers fatigue quickly. Type 2 are low-endurance, high-strength fibers. Think power lifters.
Changing Muscle Fiber Types
Exercising can change muscle fibers from one type to the other type. Heart failure changes many muscle fibers from Type 1 to Type 2, which makes you get tired faster. Heart failure also reduces muscle fiber size, making you weaker. That's why you need to do strength training and endurance training.
Muscle Signaling Systems
Signals going to and from muscles are carried by hormone and protein messengers. Heart failure changes these signaling systems for the worse. Not being physically active makes them worse yet. Regular physical activity makes these messengers work better and easier. The endothelium also changes for the worse when you are not active. That reduces blood flow. The only way to improve these systems is to exercise. Studies show that only 3 weeks after CHFers stop an exercise program, they suffer faster heart rate, more fatigue, and more shortness of breath.
Improving Neurohormone Levels
If you've read the Coreg page and ACE inhibitor page, you know about neurohormones. These little goobers cause us CHFers lots of harm. With heart failure, your levels of them go way up. Guess what? Regular exercise lowers neurohormone levels - especially norepinephrine - the one Coreg blocks.
Motor Units - Making Activity Easier
Motor units are miniature muscle controllers. When you want to use a group of muscles, you call on these motor units, which then activate and control your muscles. If you don't use your muscles much, you lose some control of these motor units. That makes physical activity harder. Motor units come in two flavors, and it takes both kinds of exercise to make them work better. One reason weight training helps CHFers is improving our ability to call on these motor units.

 Moderate Exercise Pays Off

May 22, 2002 - Skeletal muscle like your arms and legs is different from other kinds of muscle that do their thing automatically - like your heart muscle. Exercise improves skeletal muscle function in men with chronic heart failure. However, heart failure changes distribution of skeletal muscle fibers. In heart failure, type 1 (slow-twitch endurance) muscle fibers change to type 2 (fast-twitch strength) fibers. The density of tiny blood vessels called capillaries is also reduced.
     Dr. Alf Larsen studied the effects of aerobic exercise training in 15 CHFers for 3 months. Exercise was done on stationary bicycles. At the start, muscle biopsies showed signs of inflammation and muscle size loss in 5 patients. The biopsies showed fewer type 2 fibers than in healthy people but more type 2A fibers.
     Exercise improved exercise capacity, Vo2max, and 6 minute walk distance without changing ejection fraction. After exercise training, there were less type 1 fibers and more type 2B muscle fibers. All three fiber types (1, 2A, and 2B) increased in thickness.
 
Source: Int J Cardiol 2002;83:25-32,33-34.

 
 Exercise Helps CHFers

March, 2000 - We studied the effect of aerobic exercise in CHFers on distribution of muscle fiber types, enzyme activity, and on skeletal muscle signaling. Twenty-seven class 2 to class 3 CHFers did the exercise program (12 patients) or were part of a control group (15 patients).
     The training group exercised on a stationary bicycle 30 minutes 3 times a week for 3 months. This was followed by a 3 month training period at home. The control group did not change their physical activities. We studied both muscle and muscle-related enzymes by taking muscle biopsies of the legs at study start, and at 3 and 6 months. Leg muscle strength and endurance were also measured.
     Exercise capacity improved in the training group. Some enzymes became more active while others did not. This kind of training did not change the distribution of slow-twitch and fast-twitch muscle fibers.
     We found that bicycle-type exercise improved exercise endurance in CHFers but did not greatly improve strength or muscle fiber type.
 
Title: The effect of physical training on skeletal muscle in patients with chronic heart failure
Authors: Kiilavuori K, Naveri H, Salmi T, Harkonen M
Source: Eur J Heart Fail 2000 Mar;2(1):53-63
PMID: 10742704

 Moderate Exercise Pays Off

March, 1999 - Moderate exercise may be the best therapy for CHFers. A recent study shows that CHF patients in a 14 month exercise program lived longer, had less risk of heart-related death, and had fewer hospital readmissions than a control group during a 3 1/2 year follow-up.
     Ninety-nine patients with stable CHF (88 men, 11 women) were randomized into an exercise (E) group and a non-exercise (NE) group. Fifty patients exercised 3 times a week for 2 months on a stationary bicycle, and then twice a week for a year. Each session was a 20 minute warm-up followed by 40 minutes of cycling, supervised by a cardiologist.
     Almost 3 times as many patients in the NE group were re-hospitalized for CHF than in the E group. While 20 patients in the NE died of CHF, only 9 in the E group died. Six patients in the NE group suffered sudden cardiac death compared to one in the E group. Patients in the E group reported a higher quality of life. Stress tests and oxygen uptake tests improved in the E group. Catecholamine levels went down in the E group. Catecholamines are adrenaline-like substances that worsen heart failure.
     "These results clearly show that moderate exercise improves function and this means a better outcome for patients with stable CHF," says Dr. Georgiou. "We believe that exercise not only improves blood flow in the heart, but that it also increases blood flow to the skeletal muscles. This increases CHFers' ability to function." he says.
     Dr. Georgiou cautions that even stable CHF patients should ask their doctors before starting an exercise program.
 
Title: Randomized, Controlled Trial of Long-Term Moderate Exercise Training in Chronic Heart Failure
Authors: Romualdo Belardinelli, MD; Demetrios Georgiou, MD; Giovanni Cianci, MD; Augusto Purcaro, MD
Source: Circulation. 1999;99:1173-1182

 Exercise Really Does Pay Off

June 22, 2000 - Patients with chronic heart failure may benefit from a home-based exercise program. Although several questions remain about best training methods and intensity, the findings are important, writes Dr. Rainer Hambrecht.
     Seventy-three men under age 70 with chronic CHF participated. One group exercised while the other group did not. For the first 2 weeks the exercise group exercised on a bicycle for 10 minutes 4 to 6 times a day under hospital supervision. For the rest of the 6 month program, they exercised 20 minutes a day at home.
     "After 6 months, patients in the exercise group had significant improvements compared to the inactive group, in heart class, maximum ventilation, exercise time, and exercise capacity. They also had a lower resting heart rate and increased stroke volume," the authors report. In the exercise group, heart size went down. In the control group, heart size went up.
 
Source: JAMA 2000;283:3095-3101

 Exercise a Plus for CHF Patients

July, 1996 - Several reports show that short-term aerobic training improves exercise tolerance, shortness of breath on exertion, and fatigue in patients with heart failure. However, these patients are not often sent to cardiac rehab.
     This uncontrolled trial studied the long-term effects of aerobic training in chronic heart failure patients. Twenty-one people with class 2 or 3 heart failure enrolled in a program of supervised, progressive walking, 5 days per week for one year. Compliance was excellent; 15 of 21 patients completed all 52 weeks of training.
     Resting ejection fraction increased from 21% to 27% at one year. Performance on 6-minute walk test greatly improved within 4 weeks and leveled off at 16 weeks. Gains in heart and lung function developed more slowly but also leveled off at 16 weeks. Quality of life score improved. Improvements were noted at 4 weeks, 16 weeks and continued over the full 52 weeks.
     This is the first study to show that early gains from aerobic training in heart failure patients last for at least 12 months and correspond to higher life satisfaction. The safety and low cost of structured exercise support its broad use in CHF patients.
 
Title: Quality of life and cardiorespiratory function in chronic heart failure: Effects of 12 months' aerobic training
Authors: Kavanagh T et al, Heart 1996 Jul; 76:42-49
Source: Journal Watch: Cardiology 1 November 1996

 Exercise Improves CHFers' Survival

November, 1998 - Heart failure patients often have a poor quality of life, much of which is due to their exercise intolerance. Trials have shown that exercise training improves vasodilation, blood flow in the legs, muscles' ability to use oxygen, and quality of life. However, no study has been large enough to fully test whether or not exercise training will improve survival, or if it is safe.
     We studied the benefit of cardiac rehab on survival. Using the Duke database, we identified all patients with an ejection fraction less than 40%. After excluding patients with a recent heart attack, congenital heart disease, and primary valve disease, we identified patients who had participated at Duke's cardiac rehab facility.
     We came up with 70 patients with weak hearts who did cardiac rehab and 1,350 patients without cardiac rehab. There were some important differences between rehab and non-rehab patients. The rehab group had more men and less patients with history of heart failure. This wasn't surprising since heart attack patients' insurance pays for rehab and CHF patients' insurance often does not.
     We adjusted for these differences in our survival model. At 4 years, 92% of the rehab patients were still alive versus 64% of the non-rehab patients. We were not able to tell exactly how many rehab sessions would improve survival.
     Our conclusion is that cardiac rehab improves survival. The likelihood of harm for heart failure patients seems low. However, this was only a single-center observational study with only 70 rehab patients. Second, while at the rehab center, patients may receive information on other ways to improve their life style; so we may be seeing the combined effect of many life style changes. Third, we couldn't pin down how many rehab sessions it takes to provide a benefit.
 
Title: Cardiac Rehabilitation is Associated With Improved Survival in CHF Patients
Speaker: David J. Whellan, MD
Source: AHA 71st Scientific Sessions, November, 1998

 Exercise Capacity Predicts Mortality

March 13, 2002 - Dr. Jonathan Myers collected data on 6,213 men who had treadmill exercise testing. During 6.2 years of follow-up, 1,256 men died. That's an average mortality of 2.6% per year. More deaths happened in men who were older, and men with lower maximum heart rate, lower maximum blood pressure, and lower exercise capacity - in other words in men who were out of shape.
     When Dr. Myers adjusted for age, he found that the strongest predictor of mortality in both healthy men and in men with heart disease was peak exercise capacity measured in METS. "Every one MET increase in exercise capacity meant a 12% improvement in survival."
     "Our findings show a link between exercise capacity and overall mortality, but not for sure cause and effect," Dr. Myers adds. "Nevertheless, given our findings, doctors should encourage patients to improve their exercise capacity," researchers say.
 
Source: N Engl J Med 2002;346:793-801,852-853 and Reuters Health

 Figuring Target Heart Rate

August 16, 2003 - Finding the heart rate at the anaerobic threshold - the point where the body begins to starve for oxygen during exercise and lactic acid builds up in your muscles - may be the best way to determine proper target heart rate for exercise after a heart attack.
     Dr. Wybe Nieuwland measured exercise capacity in 91 men who had experienced a recent coronary event. Researchers compared Vo2max with peak exercise capacity. They also compared heart rate at anaerobic threshold with target heart rate.
     At anaerobic threshold, heart rate ranged from 55% to 96% of peak rate. For about 40% of the patients, heart rate at anaerobic threshold was more than 10% off their so-called "target" heart rate.
     So what does that mean? It means that individual exercise prescriptions based on a certain "target" heart rate may set the wrong intensity level for exercise. That may be why exercise programs are poorly tolerated by some heart patients.
     Dr. Alain Cohen-Solal adds that, "In about 15% to 20% of the cases, especially in the patient with severe heart failure and an erratic breathing pattern, the anaerobic threshold cannot be detected for sure and other methods should be used."
 
Source: Int J Cardiol 2002;84:15-21

 Exercise Lowers Risk of Heart Event

April 2, 2003 - C-reactive protein (CRP) is a sign of inflammation - high levels mean higher risk for blocked arteries (CAD). Now it seems that regular physical exercise lowers levels of this substance.
     2,833 men and women were in the PRINCE study. Forty-one percent had a history of CAD and 59% did not. All were divided into 4 groups and each group's average CRP levels were different:

Amount of ExerciseAverage CRP Level in mg/dL
those who exercised less than once a week0.26
those who exercised once a week0.20
those who exercised 2 to 3 times a week0.18
those who exercised 4 or more times a week0.17

Dr. Michelle Albert said the drop in CRP with exercise was seen in every subgroup, including smokers, nonsmokers and those with and without heart disease - even after adjusting for cholesterol levels and age. Greater drops in CRP levels with exercise were seen in men than women. Maybe women do less intense exercise or have a lower overall activity level.
     Dr. Albert said, "Physical activity may reduce inflammation and lower cardiovascular risk without drug therapy."
 
Source: 52nd annual scientific session of the American College of Cardiology

 Exercise Reverses Heart Remodeling

July 14, 2003 - The long-term effect of moderate exercise on LV remodeling, work capacity, and quality of life (QOL) was studied in 90 patients with stable CHF. All had LV systolic dysfunction. There was an exercise group of 45 patients and a control (non-exercise) group of 45 patients.
     Exercise training lasted 6 months and included riding stationary bicycles, walking, and calisthenics, done at least 3 times a week. The control group was told to avoid physical activity that caused breathlessness or fatigue. All patients had a resting echo, an exercise stress test, 6-minute walk test, and QOL measurement at study start and again after 6 months.
     At study start, EDV (end-diastolic volume) and ESV (end-systolic volume) were similar in both groups. These are measures of heart size. Ejection fraction, work capacity, peak Vo2, and walk distance were also similar in both groups.
     After 6 months, heart size decreased in exercise patients - EDV lowered from 142 to 135 mL/m2 and ESV lowered from 107 to 97 mL/m2. In non-exercising patients, it increased - EDV rose from 147 to 156 mL/m2 and ESV rose from 110 to 118 mL/m2.
     In exercise patients EF improved, but was unchanged in non-exercise patients. Exercise patients had significantly improved work capacity, peak Vo2, walk distance, and quality of life. No such improvements were seen in non-exercise patients. Exercise patients were also less likely to be readmitted to the hospital for worsening shortness of breath.
     This suggests that in stable chronic heart failure, long-term moderate exercise training helps reverse heart remodeling - improving heart size. Exercise also improves ability to function and quality of life.
 
Title: Antiremodeling Effect of Long-Term Exercise Training in Patients With Stable Chronic Heart Failure. Results of the Exercise in Left Ventricular Dysfunction and Chronic Heart Failure (ELVD-CHF) Trial.
Authors: Pantaleo Giannuzzi, Pier Luigi Temporelli, Ugo Corra, Luigi Tavazzi.
Source: Published online before print - 10.1161/01.CIR.0000081780.38477. Circulation. 2003;108:554-559.

 Resistance Training Helps HF

November 2, 2005 - Doctors often do not prescribe resistance training (like lifting weights) for fear it may somehow overstress the heart muscle. These researchers studied how 8 weeks of resistance training affected the hearts of 8 male CHFers, while 7 CHFers were a control group not exercising.
     Before and after 8 weeks of training, patients had a resting echo to measure their end-diastolic (EDD) and end-systolic dimensions (ESD), their EF, fractional shortening (FS) and stroke volume (SV). During the 8 weeks of resistance training, no bad effects on LV measurements were seen.
     After 8 weeks of resistance training, EF and FS of the exercising patients was significantly higher than in control patients. EF was 11% higher and FS was 8% higher in exercising patients. Now doctors should realize that resistance training is not only safe for CHFers but also improves them physically. The researchers recommend adding resistance training to cardiac rehab for people with heart failure.
 
Title: The effect of resistance training on left ventricular function and structure of patients with chronic heart failure.
Authors: Itamar Levingera, Roger Bronksa, David V. Codyb, Ian Lintonb, Allan Daviea.
Source: Int J Cardiol 2005;105:159-163.

 CHF, Men, Women, and Exercise

June 6, 2003 - Men with heart failure may get more improvement from an exercise program than women. This may be related to a protein called myosin heavy chain isoforms or MHCI. These are proteins produced by the body to make all kinds of muscles contract properly.
     Failing hearts have less MHCI than healthy hearts. Heart failure patients have similar problems in their skeletal muscles - like your arm and leg muscles. These abnormalities worsen exercise intolerance in CHFers. Dr. Steven Keteyian studied whether exercise training would reverse some of these abnormalities in both men and women with CHF.
     The researchers compared the effects of exercise training on exercise capacity and muscle chemistry in 10 men and 5 women with chronic heart failure. The patients completed a 14 to 24 week exercise program.
     Peak oxygen consumption improved but this was almost entirely from improvement in men (+20%) versus women (+2%). Men had lower MHCI at study (33%) start than women (50%).
     "Capillary density at study start was greater in men than in women, and neither group showed much change with training," Dr. Keteyian said. They found no differences between men and women in muscle enzyme activity before or after training.
 
Source: Am Heart J 2003;145:912-918.

 Exercise And Heart Failure

June 22, 2003 - Cardiologists discussed skeletal muscle changes during CHF at the 2003 Heart Failure meeting in Strasbourg, France. Dr. Rainer Hambrecht stated that heart function abnormalities contribute to muscle changes. He also said that abnormalities not directly caused by reduced heart function contribute to skeletal muscle changes in CHF. No clear link has been found between left heart function and exercise capacity.
     In CHF, cells' mitochondria shrink in size and volume. Dr. Hambrecht's study showed that exercise training increases both the endurance of skeletal muscle and increases the size of muscle cells' mitochondria.
     A substance called iNOS increases production of nitric oxide. Levels of iNOS are higher in CHFers' muscles than in healthy people. Amount of iNOS goes up as our ability to exercise goes down (as our Vo2max goes down). A study by Gielsen showed that exercise training reduces skeletal muscle iNOS production in CHFers. A key enzyme for quick energy use in cells is called mi-CK. CHFers are low in mi-CK compared to healthy people. We have less of it in our muscle cells.
     All this means that CHFers muscle cells don't make or use energy as well as healthy people do - regardless of our heart function.
 
Does exercise really help any of this? -  Dr. Alain Cohen-Solal said that CHF causes problems with muscle cells that can lead to cachexia and that change muscle fiber types, the amount of blood vessels in muscles, and in heavy myosin chains. Myosin is necessary for energy production.
     Dr. Cohen-Solal said that Type 1 and Type 2a fibers decrease in CHF, and slow twitch Type 2b fibers increase. Deconditioning, getting used to constant low oxygen input, and general muscle cell weakness all make it hard to function physically day to day. He believes that exercise training can improve the structure, function, and energy use of CHFers' skeletal muscles.
 
What kind of exercise works best? -  Is endurance or strength training better for CHFers? Doing some of both is best. The doctor noted that resistance training increases muscle size and strength, while endurance training increases Vo2max and endurance.
 
Beta-blockers affect muscle cells too -  Dr. Hambrecht reported on a study of how beta-blockers encourage enzymes that "kill" free radicals. Free radicals cause oxidative stress that often hurts or destroys muscle cells in the body. So beta-blockers reduce free radicals, helping skeletal muscle. Dr. Hambrecht believes these effects may partly account for the improvement in exercise capacity seen in CHFers on beta-blockers.
 
Does exercise affect CHFers' life span? -  Dr. Romualdo Belardinelli said that trials show exercise improves Vo2max, may reduce the size of enlarged hearts and improve heart function, and prevents constriction of blood vessels. He stated that EF does not predict response to exercise training, or outcome from it. Dr. Belardinelli agreed with Dr. Hambrecht that EF and exercise capacity are not related!
     Reporting on a study of 135 patients, Dr. Belardinelli said that long-term exercise training is more effective than short-term training, and can reduce 10-year mortality by 20%. His study disagrees with the EXERT trial, which showed that exercise training did not improve survival.
     Dr. Belardinelli's 99 patient study showed that Vo2max improved at 2 and 11 months versus untrained patients. Four years later, survival was higher in the exercise group. This study also suggests that exercise gives benefits in CHFers regardless of age or cause of heart failure.
     Dr. Belardinelli also mentioned the ExtraMATCH trial. This 801 patient study showed that exercise training reduced all-cause deaths and hospitalizations compared with no training - but that 28 weeks or more of training were needed for an effect on survival. In this study, CHFers with ischemic CHF had a better outcome than idiopathic CHFers.
     Dr. Belardinelli summed up by saying there is strong evidence that exercise training reduces hospitalizations and that it may improve survival. There is also strong evidence that it improves ability to function on a daily basis.

 Weight Training Helps Heart Failure

October 1, 2001 - Doctors worry that lifting weights will stress CHFers' heart. Actually, pressure load on the heart during normal weight training is the same or even less than during aerobic exercise like fast walking. Deconditioning hurts posture and weakens bones. Weight training reverses these changes and helps prevent injuries, improves balance, and improves how some very important enzymes work in your body.

Am I too old? - A study by Fiatarone showed that weight training in frail men and women 87 to 96 years of age greatly improved their strength and coordination. These older people exercised at 80% of their maximum strength for 10 weeks without complications. Strength, walking speed, stair climbing power, balance, and willingness to be active all increased.

Is Weight Training Safe? - The heart's oxygen use is better with high-repetition weight lifting than with maximum treadmill exercise. Fewer arrhythmias occur with weight lifting than with aerobic exercise in CAD patients. Trials suggest that moderate weight-lifting does not hurt CHFers and that it does improve heart function.
     When starting aerobic exercise like walking on a treadmill, your doctor may order a Vo2max test to see what you can safely do. For weight training, first get a medical exam from your heart failure specialist to see if it's okay for you to lift weights. Then start a regular and well-planned resistance training program like the one described at chfpatients.com/faq/exercises/exercises.htm.

Weight Lifting Can Be Done 2 Ways

Circuit Training - Do a series of different weight exercises all in a row - one set of each exercise. So you do one set of exercise A, then one set of exercise B, etc. You use less weight - about 30% to 50% of your maximum ability. The weight is lifted as many times as possible before moving to the next exercise "station." A weight that allows 12 to 20 repetitions is good. A 15 to 30 second rest period is taken between stations. (Healthy people don't rest between exercise stations) Each station is a different exercise for a different muscle group. You should try to use at least 5 stations per workout, going around the "circuit" 2 to 3 times.

Pumping Iron This focuses on strength and will not increase your endurance as much as circuit training. You do one set of 6 to 10 reps, rest one to three minutes, then do another set of the same exercise. Three sets per exercise is usual, but even one set per exercise will increase strength over time. Then, you use the same pattern on your next exercise.
     Often you do your upper body one day and your lower body the next; then take a day off and repeat the pattern. (Jon's Note: I do pushing muscles one day, pulling muscles the next day, then legs the next day) You need to use a higher percentage of your 1-RM than with circuit training, maybe 50% to 70%. See the next section.

How Much Weight Should I Use?

See chfpatients.com/faq/1rm.htm for the technically correct way to figure how much weight to use. I just try it light and work my up to a weight that lets me do only 6 repetitions before I tucker out. That's where I start.

Why You Should Lift Weights - The Technical Stuff
 
or go to the final summary now

Aerobics and other exercises - Activities like running and bicycling are "aerobic" because while doing them, your muscles depend on oxygen from the lungs for energy. Aerobic exercises increase strength very little but they help your endurance.
     Weight lifting is "anaerobic" because it is done at near-maximum intensity for very short periods of time (one set at a time). While lifting weights, your body uses immediate energy from ATP and creatine phosphate. Lifting weights increases strength using the "overload principle" where you make a muscle do more than it is used to doing - forcing it to adapt.

Heart failure changes muscles - Muscle loss and weakness are common in CHFers. Heart failure worsens blood flow, metabolism, and biochemistry, making activity harder. Heart rate problems also make activity harder.
     One study showed that 68% of CHFers had muscle atrophy. This causes weakness and reduces the number of muscle "motor units" available for activity. Posture suffers, you walk differently, and have poor balance, increasing risk of injury. Once atrophy happens, recovery is slow because of changes in our muscle fibers. That's why it's important for CHFers to lift weights.
     After 20 days of bed rest, oxygen uptake goes down 25% in a healthy person. The heart's stroke volume and output also go down. The human body requires activity to function properly.

Muscle fiber types - Aerobic exercise improves oxygen use in heart failure patients but reduces muscle mass. It does nothing for arms, shoulders and chest. Aerobic exercise uses mostly type one fibers (slow-twitch). Type one fibers are fatigue-resistant and are used during long activity. Weight training uses mostly type 2 (fast twitch) fibers.
     Physical training can change fibers from one type to another type. Runners have more slow-twitch fibers because of their training. Power lifters have more fast-twitch fibers because of how they train. Not using your muscles can also change slow-twitch fibers to fast-twitch fibers. That reduces your endurance without building strength. You get weaker and you get tired faster. Weight training increases strength and causes fewer muscle fibers to be needed for activity, making it easier and less tiring.
     On top of all that, in heart failure your body produces less of some enzymes. This causes more muscle fatigue and weakness. Weight lifting improves MHC (myosin heavy chain protein) makeup and this improves the situation, reducing your fatigue.

Nitric oxide - Deconditioning in heart failure patients reduces production of an enzyme called nitric oxide synthase. That's what releases nitric oxide (NO) from the cells lining your blood vessels. NO relaxes blood vessels, which reduces CHF symptoms, so less NO synthase is a bad thing.
     Cells in the endothelium that produce NO don't work right in CHFers. This is partly from deconditioning. Meyer showed that deconditioning happened in CHFers only 3 weeks after stopping exercise training. So it is critical for CHFers to stick with a regular exercise program.
     One reason you get so tired during activity is that waste builds up in your muscles. To correct this, the body usually increases blood flow to the muscles where wastes build up. This is called "reactive hyperemia." Part of that solution is to relax blood vessels so they enlarge to carry more blood - called "vasodilation." In heart failure, our blood vessels don't react properly - they don't relax and enlarge. Instead, they shrink. That's another reason we wear out so fast. Since NO relaxes blood vessels, its production and release is very important to how active we can be.
     Weight-lifting helps because it increases stress (friction) on the endothelium from direct contact with flowing blood. That makes NO be released. The resulting NO relaxes a lot of blood vessels. With regular weight lifting, over time the endothelium gets less stingy with its NO release. We then have less fatigue and shortness of breath during activity.
     So improvement from regular weight training is from several factors: Increased strength, better balance of muscle fiber types, fewer muscle motor units being needed for activity, and increased NO release.

Weight training with heart failure - Cardiac rehab programs don't focus on building strength - they build endurance. A study by Ploutz showed that less muscle is needed to lift a load after regular weight training. That means you don't get tired as fast when you are pushing, pulling, lifting, or climbing stairs.
     Studies show that weight training in people with advanced CAD is just as safe as and easier on the heart than graded treadmill exercise The same researchers showed that the heart's oxygen use is better with most-reps-possible weight lifting than with maximum treadmill exercise.
     Something many people don't know about are the "motor units" the body uses to activate your muscles. Motor units are recruited according to their size and firing rates. Small motor units are called on first, when you begin low intensity physical activity like walking. These small motor units are made of slow-twitch fibers. Large motor units are made of fast-twitch fibers. Using maximum strength requires all these motor units, at a high firing rate. Weight training increases our ability to recruit all our motor units when they are needed.
     Physical training also reduces catecholamine levels during activity, especially norepinephrine. Weight training improves blood sugar, insulin sensitivity, bone density, and energy level. Weight training may be one of the most effective and cheapest ways to improve functional ability in heart failure patients. It can be done at home with fairly cheap equipment.

Summary 

Weight training increases strength and endurance; improves muscle fiber type distribution; reduces the number of motor units needed to do work; lowers catecholamine levels in the blood; reduces heart failure symptoms when doing the normal activities of daily living; increases NO (nitric oxide) production, which relaxes arteries; and increases bone density.
     Doctors don't prescribe weight training only because they don't know much about it. Because deconditioning is common in heart failure patients, we can benefit a lot from weight training.

Title: The Effects of Resistance Exercise on Skeletal Muscle Abnormalities in Patients With Advanced Heart Failure
Author: Captain Major L. King, PhD, RN
Source: Prog Cardiovasc Nurs 16(4):142-151, 2001.

 

All information on this site is opinion only. All concepts, explanations, trials, and studies have been re-written in plain English and may contain errors. I am not a doctor. Use the reference information at the end of each article to search MedLine for more complete and accurate information. All original copyrights apply. No information on this page should be used by any person to affect their medical, legal, educational, social, or psychological treatment in any way. I am not a doctor. This web site and all its pages, graphics, and content copyright © 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Jon C.

Talk to Jon Site Index