The Myth of Cardiovascular Training for Weight Loss
Whether you have recently stepped on a scale to find that the numbers are not tipping in your favor or noticed your favorite pair of pants is getting too tight you may be thinking that it is time to lose some weight. Like most people you know that lowering your calories and starting an exercise program is the appropriate course of action. While this is likely the case, the type of exercise you choose can make a big difference in your success. Inevitably, people go straight to cardiovascular exercise. This time of year it is evidenced by all of the joggers out in the early morning and evening hours. In the winter time you can find these cardio addicts vying for the treadmills, ellipticals and stairmasters.
Certainly, cardiovascular exercise burns calories. So, why is it that for so many people it does not seem to be the right type of exercise for weight loss? Well, let’s look at caloric expenditure in general to answer this question. When calculating total caloric needs we have three types of ways we expend energy. First, we have our resting metabolic rate (RMR). Simply stated, this is the amount of calories one needs to stay alive with no activity. This comprises about 70% of total daily energy expenditure in sedentary individuals. Whether your body is using energy to allow your heart to pump, your digestive system to breakdown your food, or kidneys to filter out waste products, these all contribute to your resting metabolic rate.
In nutrition and fitness, we can estimate RMR by calculating your basal metabolic rate (BMR). Various formulas are available such as the Harris-Benedict or Katch-McArdle equations to estimate BMR. The second type of energy expenditure contributing to total caloric expenditure is the thermic effect of food. This is simply the amount of energy beyond what is expended through RMR that is used for the process of digesting food and storing the energy for later use. This generally comprises 6-10% of total energy expenditure. Finally, we have the energy that is expended through physical activity. This generally accounts for about 20% of total energy expenditure. You can see your total activity is not a large component of caloric expenditure by any means.
Cardiovascular Exercise and Weight Loss
What does this have to do with cardiovascular exercise? When you perform cardiovascular exercise you burn calories that are added to the physical activity portion of your energy equation. For a 150 lb individual this means that walking at a moderate pace for 30 minutes might burn 113 calories. Cycling at a pace of 12 to 13 miles per hour would burn 272 calories for the same amount of time and an elliptical trainer would help you burn 306 calories. Running at 6 miles per hour (10 minute mile pace) expends slightly more calories at 340 calories for half an hour. Seems low doesn’t it? Are you wondering how many hours of cardio it would take to lose one pound per week?
Let’s crunch some numbers. There are 3500 calories per pound of body weight. If you are willing to exercise seven days per week (which I wouldn’t recommend because it is not healthy) you would have to burn 500 calories per workout. If you want to accomplish that by walking it would likely take two hours and fifteen minutes of your time per day. Do you have time for that? I certainly do not.
Even if you could find the time to do lots of cardiovascular exercise, overtime this will cause additional problems. The first is that overtraining is very likely when you do long duration cardiovascular training. Exercise, while good for the body in moderation, is stressful when intensity and duration are too high. This puts quite a bit of strain on the body and can cause overuse injuries such as tendonitis, bursitis, iliotibidal syndrome, plantar fasciitis and other injuries. It can cause excess stress to the adrenal glands. When you exercise or are under stress this increases a hormone produced by the adrenals called cortisol. Cortisol levels should fall after exercise. However, with overtraining, there is prolonged stress on the body causing the adrenals to produce more and more cortisol. Cortisol can increase blood glucose levels and make the body store additional fat around the abdomen. This is certainly counterproductive to a weight loss goal. Eventually over time the strain on the adrenals is just too much. The adrenals begin to lose the ability to produce cortisol causing adrenal fatigue. This causes many symptoms including fatigue, postural hypotension, difficulty waking up, inability to handle stress, salt cravings, exercise intolerance, higher energy levels in the evening, a weakened immune system, asthma and allergies, dizziness, dark circles under the eyes, joint pain, loss of muscle, low blood sugar, loss of libido, and weight gain.
Another issue with doing excessive cardiovascular exercise is that it generally will substantially increase your appetite. Cardiovascular training is a type of aerobic exercise, meaning that it requires oxygen. Aerobic metabolism is a way of producing energy in longer duration exercise (more than two minutes). It is the energy system that we use most frequently for most activities. We preferentially use carbohydrates as the fuel for this system because they are most readily used. However, we may also use protein and fat. Generally, the lower the intensity of the activity (for example your body while you sit and read this article), the more likely your body is to use fat for fuel (Herein lies another myth, the myth of the fat burning zone! The lower the intensity of the activity the more likely you are to burn fat. However, you won’t burn very many calories without intensity.). As the workload increases your body does not have sufficient time to convert fat or protein into sugar (a process called gluconeogenesis which occurs in the liver) to use as fuel. So, when you return home from your hour jog, swim, elliptical session, or even Zumba class your blood glucose levels are low. The brain senses that fuel levels are too low and will trigger a hormone cascade to make you want to eat. The longer you wait to refuel after exercise the greater the likelihood that you will want to binge (often on all the wrong foods).
While resistance training does not burn that many calories (102 calories in 30 minutes), it still is an important part of any weight loss program. How is this helpful? Earlier I mentioned the Katch-McKardle equation which is used to calculate BMR. This equation is BMR=370 + (9.79759510 X Lean Mass in pounds). Lean mass includes everything in your body that is not fat. Resistance training is an ideal way to increase lean mass (muscle mass specifically). This ultimately will help to increase your BMR.
Choose 8-10 exercises for each of the major body parts including legs, chest, back, shoulders, biceps and triceps. The more muscles an exercise recruits, the more calories it will help you expend. This means squats, lunges, deadlifts, pushups and rows will help you burn more calories than lateral raises, hamstring curls, leg extensions, biceps curls, triceps kickbacks, calf raises and other single-joint exercises. Make sure to choose sets, repetitions and rest intervals appropriate for your training goal.
To increase strength levels, choose a heavy weight that you can lift only one to five times. Take longer rests, typically three to five minutes between sets. Since you will be doing fewer repetitions you can aim for four to six total sets. If your goal is to gain muscle, typically we aim for eight to 12 repetitions. Higher volume training is ideal for this goal so anywhere from three to five sets is ideal with 30 to 60 seconds rest between sets. If this is your first time doing resistance training, you are looking to improve endurance or are recovering from an injury choose to do 12 to 20 repetitions for a total of one to three sets. Taking minimal rest (0 to 90 seconds) is recommended. Consider varying your program every four weeks to allow your body to continue to make progress.
Circuit training for half an hour may still only burn 272 calories, but it will also help you gain lean muscle mass. Circuits generally contain 8-10 exercises including resistance training, calisthenics and plyometrics. An example circuit of moderate difficulty might include: squat jumps, lat pull, chest press, reverse lunges, 1-leg deadlift, reverse flies, stability ball crunch and calf raises. Since circuit training also counts as cardiovascular training this also increases your heart rate beyond typical levels found during strength training which allows you to burn even more calories.
Peripheral Heart Action
Looking for a greater cardiovascular challenge? Consider peripheral heart action training. This is a variation on strength training that alternates upper and lower body exercises. This forces the heart to work harder as it has to pump blood both to the upper and lower limbs in rapid succession. So, for example, an example of a basic peripheral heart action training program might be the following: forward lunges, pushups, squats, rows, deadlifts, shoulder press, step ups, triceps dips, stability ball hamstring curls, biceps curls.
If you are looking to increase lean muscle, but still burn a few additional calories consider compound sets. This type of training pairs two exercises back-to-back for different body parts with minimal rest. Consider pairing legs with shoulders, chest with back, and biceps with triceps. This will allow greater caloric expenditure, keep the workout fast paced, and presents a greater challenge for your heart.
Super sets are similar to compound sets. However, in this case you will do two exercises for the same body part back-to-back with minimal rest. You will need to do only six to 10 repetitions per exercise so that the total volume isn’t too high. Some example super sets might include:
- Bench press and pushups
- Pull ups and rows
- Lunges and Squats
- Shoulder press and reverse flies
- Deadlift and hamstring curls
Interval training approaches the fat loss equation from a different angle. An interval is simply a short period of work followed by an active rest. This can be done using cardiovascular equipment such as a treadmill, elliptical, recumbent or upright bike or stair master. It can also be done outdoors doing sprints (or fast walk) followed by a jog or walk. Resistance training, rebound training (trampoline), jump ropes and calisthenics may also be used. The higher the intensity of the interval, the shorter the duration should be. So, if you are going to do an all-out sprint (can also be done on an elliptical or bike for a lower impact option), consider an interval of just 10 to 15 seconds in length.
There are many benefits to using such a brief interval. The first is that when you do such a short sprint you are using an anaerobic energy system. This means the energy system does not require oxygen. When you do such a high intensity sprint you will not notice your breath until after you stop. Heart rate will continue to elevate even after you finish sprinting. This will help you burn more calories due to EPOC. EPOC stands for excess post-exercise oxygen consumption and means that your body’s metabolism will continue to be elevated even after you stop exercising. This occurs quite a bit with interval training and will also happen with various forms of resistance training (see above).
Eating for Weight Loss
I would be remiss to discuss weight loss without discussing diet (which is indeed a four letter word!). As a certified nutrition specialist (CNS), nothing frustrates me more than hearing about all of the fad diets. Most help you lose weight by cutting out a much needed category of nutrient. For example, the Atkins diet cuts out carbohydrates (even healthy fruits and many vegetables don’t make the cut in the induction stage of this diet). Each of us are biochemically unique. This means that one man’s food is another man’s poison. While that might seem trite, I have found this to be true. Some need to rely heavily on protein to keep them satiated and find that starchier foods such as grains and potatoes pack on the pounds. Others find that a predominantly plant-based diet high in fruits, vegetables, whole grains and beans is a better way to go. Regardless of your particular body chemistry there are certainly some basic guidelines that apply to all of us.
- Eat 7 to 11 servings of fruits and vegetables per day. Only 1-3 of these servings should be fruits. Include plenty of dark, leafy greens such as broccoli, Brussels sprouts, kale, arugula, spinach and Swiss chard, as well as brightly colored vegetables including peppers, carrots, radishes, sweet potatoes, squash, and eggplant.
- Drink half of your body weight in ounces of water per day. This means a 150 pound individual requires 75 ounces of water.
- Get adequate protein. 10% to 35% of calories should come from protein. This includes animal proteins including poultry, fish, shellfish, eggs, red meat, and dairy products. Vegetarian options include nuts, seeds, beans, tofu, seitan, tempeh, and even vegan protein powders (rice, pea, hemp, soy, etc.).
- Avoid eating too many refined carbohydrates such as white rice, white bread, white pasta, cookies, cakes, muffins, candy and other sugary treats. These will lead to elevated blood glucose levels, weight gain, insulin resistance, metabolic syndrome and Type-two diabetes.
- Make sure to include sufficient fat in your diet, but don’t eat too much fat either. Fat should comprise no more than 30% of your calories. Choose from healthy omega-3 rich fats such as fish oils, walnuts, and flax; olive oil; avocado, nuts and seeds; and coconut oil. Avoid partially hydrogenated oils which will increase your cardiovascular disease risk (often found in shelf-stable peanut butter, crackers, cookies, and margarine).
- Don’t overdo grains and make sure they are whole grains. Watch portion sizes. A cup of most whole grains (such as brown rice) contains 200 calories.
- Remember to watch overall caloric intake. Do not starve yourself as this is counterproductive, but do not eat excessive calories either.
- Allow yourself the occasional cheat. Better to eat a small amount of a favorite food than deny yourself which will likely cause you to binge on it later.
- Vary your diet. Avoid eating the same foods all the time. Not only does this limit your nutrient intake, but it can cause digestive problems and food sensitivities.
- Use plenty of spices and herbs. Not only do these add lots of additional flavor without calories, they are full of phytonutrients, antioxidants, anti-inflammatory properties, and some are even anti-microbial.
Remember, in the end your nutrition and exercise program should reflect your own personal goals, interests and needs. Clients always ask me what the best type of exercise is. The simple answer is anything that you enjoy. This is the only way to make it part of your lifestyle permanently. Food should also be enjoyable. Experiment. Try new things. You might be amazed at what you will discover!
Jessica Pizano is the owner of Fit to You, LLC, which offers clinical nutrition and nutrigenomic counseling, as well as personalized training programs. Her concentrations include genetics and nutrigenomics, general health and fitness, weight loss, food allergies/sensitivities, autoimmune disease, obesity intervention, pre- and post-natal exercise and nutrition, and Pilates. She earned a master’s degree in human nutrition that emphasizes functional medicine at the University of Bridgeport. She is a certified nutrition specialist through the Board for Certified Nutrition Specialists. She is continuing her studies at Maryland University of Integrative Health where she is pursuing a doctor of clinical nutrition and is also an adjunct faculty member teaching nutritional genomics. Currently, Jessica practices nutrition counseling, nutrigenomics, and personal training in her studio in Avon. She may be contacted at (860) 321-7234 or online at: www.fittoyouct.com.