Sometimes when we want to lose weight, we focus on the number on the scale and forget about the importance of losing body fat. The majority of body fat (over 80 percent) is stored in fat cells. To get rid of it, you need to use it for energy.

This is one of the great things about ketosis: when your body is accustomed to burning fat for fuel, it can use body fat as well as dietary fat. And when you increase the amount of energy your body needs by exercising, all that extra energy comes from burning more fat! But if you are a sugar burner and fuel your body with carbs, you just burn sugar instead, making it much harder to lose body fat.

Ketosis is great for athletic performance, too. Our bodies can store over 40,000 calories of fat but only 2,000 calories of carbs, so when we’re burning fat instead of sugar, there’s a lot more fuel available at any given time. This is why carb-burning marathoners “hit the wall” during a race and need gel packs and Gatorade—they’ve used up the glucose they had available for fuel. They are low in performance at the end of the race, too, due to the depletion of carbs in their muscles and liver. Here’s something to think about: migratory birds and whales rely on stored fat to fuel their long journeys.

Developing your fat engine will increase the amount of energy you can generate and reduce the amount of carbs you use. Added together, you have a more stable and enduring energy supply, better endurance, and faster finish times.

In this section, I’ll look at some of the most effective kinds of exercise and offer my tips for getting the best results from exercise.

cardio

Awesome things happen to your body when you work out at an intense rate. Not only does cardiovascular exercise improve the efficiency of your heart and lungs, it also increases the rate at which your body burns fuel. Over time, burning more fuel means that you will lose weight.

I know that those of you who are fans of Gary Taubes, who wrote Why We Get Fat , will think I am wrong. He believes exercise has nothing to do with weight loss, and I understand his points, but I have seen the benefits of exercise and cardio, especially when it comes to losing body fat. Studies show that a number of metabolic changes occur with cardiovascular exercise that uniquely enhance fat metabolism, including the following:

All this data shows that with consistent, progressive cardiovascular exercise, we can truly expand our bodies to be awesome fat-burners. When our bodies are tired and we want to stop exercising, it’s gratifying to know that when we push through the pain, we are creating more fat-burning furnaces (mitochondria)!

pumping iron

Iron is needed to carry oxygen to the mitochondria of your cells, where fat is burned during oxidation. (As you might guess from the name, oxidation requires oxygen.) If you have an iron deficiency, therefore, it is hard for your body to burn fat. Worse, when you push yourself too hard, you end up depleting this mineral even more. Women, take note: if you are feeling tired, losing your hair, and not losing weight with exercise, you are likely low in iron. About 90 percent of women who are low in iron can attribute the deficiency to three causes: menstruation (loss of blood equals loss of iron); a diet filled with gluten, which inhibits the body’s ability to absorb iron; and/or excess cardio.

strength training

Most women use their valuable time for cardiovascular or aerobic exercise, and I used to be one of them. I would run twelve miles a day and compete in marathons, but the scale didn’t budge. I finally started taking a fitness class called BodyPump, which uses light to moderate weights, and the pounds began to melt off. I stopped running so much and started strength training.

I found that there are other benefits to strength training, too, in addition to weight loss:

• It helps lift your mood. Studies prove that watching yourself lift heavier and heavier weights builds confidence and reduces depression, even if you aren’t losing weight.

• It helps you develop a strong and healthy body for daily movement throughout life.

The most beneficial movements are multi-joint exercises, which use more than one muscle in a single movement—one example is a bench press, which uses both the shoulder and elbow joints as well as several muscle groups. Your metabolism and heart rate are directly related to the total volume of muscle mass being used, so multi-joint movements burn more calories by stimulating more muscles.

Some people are concerned that a low-carb diet, like the ketogenic diet, will prevent them from building muscle with strength training. However, in a well-designed low-carb, high-fat diet, there is less protein oxidation and double the fat oxidation, which means muscle is preserved while you burn fat!

There are a lot of myths floating around about strength training. Let’s take the top myths down one by one.

are you gaining weight with strength training?

One reason women say their pants fit tighter after lifting heavier weights is that they are overconsuming carbohydrates or protein. Don’t grab oatmeal and skim milk—or worse, a brownie—after all your hard work. Did you know a pound of fat is 3,500 calories and running a whole marathon burns only about 2,500 calories? So don’t think that just because you performed a kick-butt workout, you can have a bag of Twizzlers. Learn the proper ways to fuel your body—it’s essential for your health and outward appearance. And treat yourself in other ways! A one-hour massage is a great way to reward your muscles for their hard work.

Myth 1: For weight loss, I should do only cardio exercise.

While cardio is important, it isn’t the only type of exercise that can help you lose fat. Strength training increases muscle mass, and the more muscle you have, the more calories you’ll burn all day long.

Muscle is denser than fat and takes up less space. That means when you lose fat and gain muscle, you’ll be slimmer and trimmer.

Myth 2: To tone my muscles, I should use lighter weights and do more reps.

In order to create strong muscles, you must lift enough weight to break down the muscles, so they can be repaired to be even stronger. Muscles break down as you lift, and they repair and grow as you rest. If you plan on doing fifteen triceps extensions, choose a weight that allows you to only do fifteen reps. You want your body to feel the difficulty of lifting the weight in order for the muscle to become defined. That lean, defined look comes from losing body fat, which means heavy weights equals more fat-burning!

Myth 3: Strength training makes women bulk up.

This popular myth continues regardless of the fact that women don’t have the amount of testosterone required to build huge muscles. In fact, even men struggle to gain muscle and spend hours lifting to create a muscular physique.

Lifting heavy weights can benefit both men and women. In fact, challenging your body with heavy weights is the only way you’ll really see results and get stronger. I’ve been lifting heavy weights for years, and I have never even come close to looking like a bodybuilder; most women who lift weights regularly would agree. Remember, muscle takes up less space than fat. Adding muscle (along with doing cardio and eating a healthy diet, of course) helps you lose fat, which means that you’ll be leaner and more defined.

interval training

Interval training is my favorite way to burn the most calories possible. Not only do you burn a ton of calories while you’re doing it, it also stimulates your metabolism to a far greater degree than lower-intensity training. This is referred to as the afterburn effect. Interval training causes your muscles to go crazy with activity; I call it a metabolic disturbance. This crazy metabolism boost causes lots of calorie-burning after exercise to get your body back to normal. The result is that you end up burning more fat and calories in the post-exercise period as your body tries to get things under control.

Interval training is basically what it sounds like, alternating intervals of high-intensity and low-intensity exercise. It’s based on a simple concept: go fast, go slow, repeat. It sounds simple, but this formula has an incredible number of potential variations and strategies.

• It saves time. If you normally spend an hour and a half in the gym following the “fat-burning zone” philosophy, know that you’ll work yourself just as hard in forty-five minutes with interval training.

• Higher intensities stimulate your metabolism far more after the workouts than lower-intensity training. This means you continue to burn calories and fat for long periods after you’re done training—an extra 150 to 250 calories burned without any extra work!

• It combats boredom. It’s fun, and time flies during each session because you’re working in cycles of high and low intensity instead of spending a long time at any one activity. I like to make a playlist of songs to match the intensity of the workout: a warm-up song, a fast-paced song, a recovery-paced song, and repeat!

• It challenges your aerobic and anaerobic systems at the same time, so you’re improving your body’s capacity to burn calories at a higher rate.

• It helps you add new muscle, which speeds up your metabolism of fat even at rest.

Many studies have proven the value of interval training. One followed a group of overweight women and assigned them to one of two groups. The first group worked out using high-intensity intervals, which involved two minutes of maximum effort followed by three minutes at a lower intensity. The second group worked out at a constant pace the whole time. The lengths of the workouts were varied so that both groups burned 300 calories. At the conclusion of the study, fitness levels in the interval group had improved by 13 percent, while no improvements were found in the steady-state group. The first group also continued to burn calories after the workout was finished.

human growth hormone

Human growth hormone is necessary for building muscle (which, in turn, increases metabolism), but it’s also the fat-burning hormone. The combination of the two means that more growth hormone is great for losing weight.

Growth hormone is inversely related to insulin: if one is high, the other is low. So if you eat something (especially carbohydrates) before a workout, you will be spiking your insulin level and your growth hormone level will be low. This is one reason it’s helpful to exercise on an empty stomach ( see here for other reasons). Short, high-intensity workouts are also awesome for stimulating growth hormone, and when lifting weights, that burn that you feel at the end means an increase in growth hormone.

circuit training: strength + cardio

Circuit training is a combination of strength training and cardiovascular exercise. If you’re looking for a workout that provides allover fitness benefits, from revving up your metabolism to extending your endurance, look no further than circuit training.

A circuit-training workout combines cardio activity like jogging with a resistance workout, with little to no rest between exercises. The absence of long rest periods makes circuit training as effective as a cardio-based high-intensity interval workout ( see here ), which raises your heart rate and boosts metabolism by building muscles. Like interval training, circuit training burns a ton of calories, not just during the workout but for hours afterward—the afterburn effect. Minimizing rest time between exercises is as important as the exercises themselves. The more downtime between movements, the more your heart rate and metabolic rate decrease.

I love a circuit-training class at my local gym called Bootcamp. We rotate stations that include one strength-training activity and one cardiovascular activity, and two people share each station. For example, one station might be biceps curls for one person and explosive step-ups over an elevated step for the second person; you switch every minute or two. Once you are done with a station, you quickly do fifteen push-ups, sit-ups, or squats and then move on to the next heart-pumping station.

For a more advanced workout, repeat the whole cycle. Then walk to cool down and stretch!

yoga

About eight years ago, I taught yoga at the Andersen Windows corporate office over the lunch hour. Just about everyone in the class was brand-new to yoga. They mostly wanted a break from their desks and a time to relax. But after the first class, they all were surprised at how much they sweated and “felt the burn” while de-stressing at the same time. They were hooked. I loved hearing after each class that yoga had changed their lives in some way—they had less back pain, were making better food choices, felt happier and calmer, and more.

Yoga is one of the most helpful workouts for fighting stubborn fat stores. Research has found that yoga decreases levels of stress hormones and increases insulin sensitivity, which helps the body burn rather than store energy. In addition, stress, bad food habits, lack of energy, and thyroid problems can all be sources of weight gain, and practicing yoga can help with all of these.

That said, most types of yoga don’t have the calorie-burning abilities of aerobic exercise. A 150-pound person will burn 150 calories in an hour of yoga, compared to 311 calories in an hour of walking at 3 miles per hour. Yoga’s best benefit when it comes to weight loss is that it puts you in touch with your body in a way nothing else can.

Yoga isn’t just exercise; it is a mind-body connection. It helps us become more in touch with our bodies and how we feel. It creates a sense of mindfulness, which is the ability to monitor what is happening internally. It helps change the relationship between the mind and body, and in time, that translates into a change in eating habits. The strong mind-body connection forged in yoga makes you more aware of what you eat and how it feels to be full, and the conscious awareness of your body translates to better appetite control. You become more aware of which foods nourish you and which make you feel lethargic.

So if you think you want to change your routine or the way you approach food, or get over harmful eating patterns, yoga can help you make those changes.

exercise helps break bad habits

Habits are hard to break. Instead of just stopping a bad habit, I like to help people form new healthy habits in its place—it makes stopping the bad habit much easier, and of course it offers benefits of its own. Exercise can be an effective tool as one of those helpful good habits. Here’s an example from my own life: I grew up eating a bedtime snack, and it was the hardest habit for me to break. Practicing a bedtime yoga routine, which calms the mind and body, helped me replace that unhealthy snack with a habit that’s actually good for me.

exercise tips for burning more fat

There are some tricks to exercising that can increase fat-burning. Granted, these tips will not work for everyone since we need to fit in exercise whenever we can, and some people may want to enhance performance rather than burn fat. But if fat loss is your goal, check this out!

• Exercise in the morning on an empty stomach. If your goal is to burn fat, it’s best to exercise first thing in the morning on an empty stomach. (To prevent dehydration, drink a large glass of ice water mixed with a touch of quality salt first.) This will burn 300 percent more body fat than exercising any other time of the day because there is no glycogen (stored carbohydrates) in your liver to burn, so your body has to go directly into the fat stores to get the energy necessary to complete the activity. However, if you are diabetic or have other medical issues, this is not healthy. This suggestion is only for people who have no medical conditions and are not training to win races.

• Do cardio exercise right after weight training. It takes twenty to thirty minutes of exercise to exhaust the glucose immediately available for fuel (unless you’re working out first thing in the morning on an empty stomach—see above). It’s only then that you’ll start to burn body fat. By performing weight training exercises before cardio, you’ll deplete your available glucose faster, so you start burning fat sooner. Lifting weights first also means you have lots of energy to focus on correct posture, decreasing the chance of injury.

• Change the exercise. When you do one exercise consistently, your muscles get used to it. Workouts get easier and those muscles don’t have to work as hard, so you burn fewer calories. Frequently changing your exercise makes your muscles work harder and causes an increase in heart rate, which means an increase in calories burned.

• Change the duration of exercise. This is important because you want to prevent your body from adjusting to a constant amount of activity. As soon as the body adapts to a kind of exercise, it’s easier for the muscles to perform. This is good for performance, but it becomes tougher to reach the fat-burning zone. Extending the length of your workout can compensate.

the exercise of daily activities

There are two kinds of physical activity: planned activity, such as running on a treadmill, and the unconscious movements that we perform daily, such as tapping a foot in a meeting or simply moving to get from one place to another. Both kinds of activities require fuel and affect our metabolism, which determines how our bodies burn fuel. Overall, activity level makes up 15 to 30 percent of our metabolism.

But we often overestimate how much fuel we really burn during planned exercise. To put it in perspective, a runner burns about 2,500 calories during a marathon, and it takes 3,500 calories to burn 1 pound of fat! Plus, it can be difficult to make time for exercise; we’re all so busy, it can be hard to get in three one-hour workouts a week. Here’s the good news: the calories burned during unplanned activity can add up fast. Going to the grocery store and cooking dinner can burn as many calories as a boring forty-minute run on a treadmill.

So instead of going to the gym after work, stressing out on the way home because you don’t have anything planned for dinner, and stopping at a restaurant for takeout, go to the grocery store, power shop, and go home and make your family a healthy meal! You’ll have burned the same amount of calories, and you’ll be giving your body the healthy fuel it needs to thrive.

This is not to say that exercise is unimportant. It definitely is! It strengthens your heart, lungs, and muscles, which is important for overall health. Recent studies have found that exercise is more helpful in treating depression than antidepressant medications. But when it comes to weight loss, it’s not everything. Do I exercise? Yes, I run, bike, walk, lift weights, practice yoga—I love to move. But I did all this when I was fat, too. Nutrition was the missing key to successful weight loss.

I see exercise as a tool to help you live a healthy lifestyle. Do not push yourself by living at the gym or on a treadmill in order to lose more weight. It is more about what you put into your mouth than how many miles your legs can run.

fitness tip: wear a pedometer!

Every car has an odometer that records the miles it has traveled. Similarly, a pedometer measures steps. Walking 10,000 steps a day burns 300 to 400 calories. Wearing a pedometer can enhance your motivation to increase your number of daily steps. Focus on one day at a time. Over time, you will find yourself going for an extra walk, taking extra steps from the parking lot, and expending a few more calories here and there. These small changes add up over time and lead to stable, lifelong results.

the dangers of too much exercise

I love to exercise for so many reasons. I love my morning run in the country: the silence, the feeling of gratitude, seeing deer. But it took me years to enjoy running. When I first started, I was aiming for a half mile, and even that was tough for me. Now I run every morning without hardship, and I do it not for weight loss but because I enjoy it.

I did, however, sign up for a marathon for weight loss six years ago, and guess what happened while I was running twice a day? I gained weight, even though I was eating the same low-carb diet. What was going on?! I was overtraining. My high-intensity exercise routine had pushed my body’s stress response too far, which led to a cascade of biochemical responses that damaged my health.

Most people do cardiovascular exercise to lose weight. Unfortunately, too much cardio stimulates cortisol, a stress hormone that tells your body to hang on to fat stores. Cortisol is released when the body is under all kinds of stress—work, family life, lack of sleep, poor eating habits, and, yes, excess exercise (such as marathon training) can all stimulate cortisol.

Chronically high levels of cortisol aren’t just a problem for weight loss. They also increase your risk for a variety of health issues, such as depression, sleep disturbances, and digestive issues. Also, cortisol and testosterone seem to conflict; the more aerobic work you do, the more cortisol is released and the less testosterone is available to build muscle (plus, for men, lower testosterone has all kinds of effects on libido and erectile function).

Aside from cutting back on excessive intense exercise, there’s a simple way to lower cortisol: get more sleep! (This is why people tend to gain weight in the summer: with the longer days, they’re not getting enough sleep.)

Stress, whether from excess cardio or other life stressors, also affects neurotransmitters such as serotonin, GABA, and dopamine. These are our feel-good, antianxiety brain chemicals, and burning them out with stress and too much intense exercise can lead to depression, chronic fatigue, and sleep disorders. A shortage of these neurotransmitters also can cause serious thyroid conditions, such as hypothyroidism, which is known to cause weight gain, depression, and digestive dysfunction. Plus, low serotonin levels are associated with cravings for carbohydrates and binge eating.

If you are already living a life filled with stress from work, school, or family, know that exercise is another stressor. True, exercise is known to be more of a “healthy stress,” but your adrenal glands don’t know the difference. If you have adrenal fatigue, you may want to read the section on yoga, which is a great low-impact exercise that can also help you de-stress ( see here ).