Classes today (Saturday 9/23) will be held as usual. The lion dance was postponed.

There are a lot of misconceptions when it comes to weight loss, and these misconceptions can lead to a lot of frustration for those trying to lose weight. As a trainer, I came across many such misconceptions, but these three were by far the most common.

Myth 1: With the right combination of diet and exercise, I can look just like [insert actor/model/whatever here]. We like to think that we are in total control of our bodies (this particular logical fallacy is known as attribution bias for those keeping score at home), but in reality, there are significant and permanent limitations on that control.

First, your basic shape (skeletal structure) is determined by genetics. Some people have thin frames, others have heavier frames. In addition, we all tend, regardless of diet or exercise, to carry a certain amount of weight on those frames (exercise physiologists divide people into three categories: ectomorphs, mesomorphs, and endomorphs). This cannot be changed. A lot of people who want to be "thin" simply can't be. (Similarly, many "99-pound weaklings" want to have large muscles, but no amount of training will achieve this.) This is NOT to say that diet and exercise cannot achieve weight loss and muscle development or even, within limits, change the shape of your body. However, the effects of diet and exercise are determined to a large extent by genetics and physiology. Realistic goals are important for weight loss; if you want something that's physiologically impossible, you will only set yourself up for failure.

Secondly, the effects of diet and exercise are not exclusively, nor even primarily in most cases, reflected in changes to structural shape/appearance. In other words, the functional effects may be far more substantial than the structural ones. For example, marathon runners have highly developed but not large muscles, while power lifters often appear fat and out of shape, but they can lift immense loads. Both groups of athletes have highly conditioned muscles, but have them switch roles, and the results would not be very impressive, regardless of their diets and exercise regimens. Training is crucially important, but it doesn't trump genetics.

Lastly, some people gain/lose weight easily, others do not. This is not particularly well understood but likely comes down to genetics as well. The bottom line is that you must learn to embrace the fact that you have only so much control over your body; reasonable weight loss is a very achievable goal, but remember that a healthful diet and routine exercise are intrinsically important for health regardless of how much they affect your weight.

Myth 2: To lose weight, just do lots of repetitions with light weights. This seems to make intuitive sense, but it's quite wrong. Much of the confusion stems from the unfortunate concept of "burning fat". Most people seem to think that when they do more, they "burn" more calories, which will come from fat. Not really. A strenuous, one-hour long workout will probably burn, at most, about 300 calories; that's the equivalent of an apple and a small granola bar. To make things worse, most of those calories will not come from fat. Although fat has a lot more energy per gram than carbohydrates (9 kcal/g vs. 4 kcal/g, respectively), it's a much less readily accessible energy source (i.e., it's a much slower process to release energy from fat than from carbohydrates). So, the bulk of those 300 calories will come from muscle glycogen, not fat.

How, then, do you use fat? You will not burn much fat during a workout, but you will for less pressing energy demands, namely those associated with staying alive. The average adult has a basal metabolic rate of 1200-1400 kcal/day; that's the energy you expend to keep your heart pumping, your organs functioning, and your core temperature stabile. In other words, just being alive for a day takes about 4 times the energy that a strenuous one-hour workout requires. What exercise does is increase (slightly) your metabolic rate and create energy deficits (by depleting glycogen levels, creating minor tissue damage that must be repaired, etc.). Since fat is a slow but rich energy source, it is ideal for these kinds of processes. Therefore, you do burn fat as a result of exercise, but mostly in the 24 hours or so after your workout has ended. Furthermore, this effect has little to do with the kind of workout you do (this isn't strictly true, but I am simplifying a bit for the sake of clarity); generally speaking, the effect is roughly proportional to the intensity of the workout, not the kind of workout. There are a few things you should keep in mind, however.

First, if you are eating more calories than the combination of your basal metabolic rate and your exercise deficit (in this example, 1500-1700 kcal/day), you will likely not see any significant weight loss, as any fat you burn will quickly be replaced. Weight and weight loss are not exclusively determined by the balance between intake and expenditure of calories, but it is a significant component.

Secondly, because fat is such a rich energy source, it goes a long way. No matter what the amount of carbohydrates you burn through in a workout, it take less than half that amount of fat to replace that energy.

Lastly, people tend to burn fat according to the "last stored, first used" principle. Your body will use its most recent fat deposits first, working backward to its earliest deposits. Where your body stores fat (and in what order) is largely determined by genetics.

Myth 3: If I do enough crunches, I'll lose the last of my tummy fat. By now, you probably have a sense for why this is wrong. Muscle glycogen is site specific, fat is not. In other words, crunches will definitely deplete the glycogen in your abdominal muscles, but not necessarily the fat in your abdomen; there is no connection between the location of an exercise and the location from which fat is utilized. Think about those power lifters again; they all have exceptionally strong muscles, but most of them also have a fairly large amount of fat on them as well, even in places where their muscles are most heavily worked.

What should you take from all this? Here are a few general guidelines for losing weight:

(1) Set realistic goals. It is unhealthy to lose more than 2 lbs. per week, but it is also unrealistic to expect major physical changes in a short time. Accept your shape and basic physiological body type, and work with what you've got.

(2) Use yourself as a model, not, well, a model. It's much better to think "I'd like to look like I did when I was 30" than to think "I'd like to look like Brangelina".

(3) Even better, forget how you look--how do you feel? Focusing on how you feel, especially after you've been on a new regimen for at least a few weeks, will often be a better guage of success than a mirror or a scale. For example, are you sleeping better? Do you have more energy? Are you stronger? Has your mood changed? etc.

(4) Input < output. If you eat more than you use, you will probably not lose weight. However, don't starve yourself. You will not only fail to achieve sustained weight loss, but you will also do considerable harm to your body (and mind). Start with small dietary changes and gradually modify your habits until your diet is in line with your needs.

(5) Your diet should be composed of as much natural food (i.e., unprocessed or minimally processed foods) as possible. Fresh meat, eggs, nuts, legumes, vegetables, and fruits and minimally processed foods, such as yogurt or juice, are generally better for you than heavily processed foods like chips, granola bars, or breakfast cereal.

(6) Combine regular, strenuous exercise (3-6 days/week) with everyday exercise (e.g., use stairs instead of escalators/elevators, use a push mower instead of an electric/gas mower, rake instead of using a leaf blower, walk/bike instead of driving when feasible, play with your dogs/kids/whatever, etc.).

There are three general attributes of skeletal muscle that athletes try to develop: strength, power, and endurance. Although these attributes are not really separable, they reflect the different physical capacities of muscles.

Strength

Strength is simply the maximum contractile force that a muscle can exert. Functionally, this is defined as your one repetition maximum, or 1RM. For example, if the absolute maximum amount of weight you can curl one time is 40 lbs., that gives you an estimate of the strength of your biceps brachii. Physiologically, strength is determined predominantly by cross-sectional muscle area. Basically, the bigger the muscle is, the stronger it is. (Although other variables are involved, such as the communication between nerves and muscles and the efficiency of energy metabolism, these have a much smaller overall effect on strength.) To understand the link between cross-sectional muscle area and strength, think of muscle as being a little bit like rope; the more strands there are in the rope, the greater the load it can lift without snapping.

Power

Power is the amount of work you can do per unit of time. Unlike strength, which is simply a measurement of contractile force, power is the application of that force to do work (e.g., to move something or move yourself) as a function of time. Consider two examples, based on the one above.

If you can curl 40 lbs. in 1 second, that is twice as powerful as curling 40 lbs. in 2 seconds.

If you can curl 80 lbs. in 1 second, that is twice as powerful as curling 40 lbs. in 1 second.

This is why power is often used interchangeably with concepts like "explosiveness"; it is not just the force your muscles exert but the way that force is applied.

Although cross-sectional muscle area is a component of power, other variables, such as nerve-muscle communication, muscle fiber recruitment, and muscle fiber composition, play a much larger role.

Endurance

Endurance is the ability of a muscle to sustain repeated contractions for an extended period of time. Functionally, let's return to our previous example. If your 1RM is the maximum amount of weight you can move one time, endurance is the number of times you can move a certain amount of weight. Since we know your 1RM is 40 lbs. for the curl, to test the endurance of your biceps brachii, you may instead determine how many times you can curl, say, 15 lbs. before you reach muscle failure (the inability to initiate a contraction). That gives you an estimate of muscle endurance.

Endurance is determined mostly by muscle fiber composition, cardio-pulmonary efficiency, and energy metabolism.

Now, as mentioned above, you cannot completely separate these three capacities of skeletal muscle in reality. All workouts will contribute to all three attributes, but you can emphasize one over the others to some extent. There are many many ways to design workouts that focus on one or two of these components (many of which will be the subjects of future posts), but here is a general rule: as you move from power to strenth to endurance, increase the number of repetitions (by decreasing the resistance) and decrease the rest between sets:

Power: 3-5 sets of 1-5 repetitions, 2-5 minutes of rest between sets

Strength: 3-5 sets of 8-12 repetitions, 1-2 minutes of rest between sets

Endurance: 3-5 sets of >15 repetitions, <1 minute of rest between sets

Future posts will explore more sophisticated ways to train these attributes.

Any given workout should have, at its most basic level, three components:

1. Warm-up

2. Primary workout

3. Cool-down

The first part of a workout, the warm-up, is typically 5 to 10 minutes of light to moderate activity designed to ease you into a more vigorous workout. It is important for several reasons. First, as the term suggests, it warms up your muscle tissue, making it more pliable and more responsive, thus reducing the risk of injury and improving performance. Secondly, warming up loosens the joints, which helps to prevent injury and enable proper mechanics. Thirdly, it gradually raises your heart rate and blood pressure and dialates your blood vessels, preparing your cardio-pulmonary system for increased activity, and begins diverting blood flow from organs like the liver and kidneys to the muscles. Lastly, warming up can safely alert you to any areas that are sore, stiff, or mildly injured, so that you can properly address them prior to strenuous exertion.

Good warm-ups typically include two components:

Light movement of the whole body, such as jogging, jumping rope, or any other activity performed at low to moderate intensity; generally speaking, the more fit you are, the closer to moderate intensity your warm-up should be.

Dynamic stretching, which involves moving through the (nearly) full range of motion about the major joints without holding the stretch or straining your flexibility; this includes such exercises as arm circles, hip rotations, and torso twists.

Some general guidelines for warm-ups:

The colder the ambient temperature, the longer the warm-up should be. Ten minutes is generally sufficient in all but the most inclement conditions, and as little as 5 minutes is fine in warm environments.

Avoid static stretching (i.e., holding stretches for extended periods to improve flexibility); when muscles are not warmed up, they are not pliable, and so it is both ineffective and potentially harmful to stretch this way without properly warming up first.

Avoid explosive or other high-intensity movements or exercises; begin slowly and progress gradually when warming up.

The second part of a workout, the primary workout, is obviously the central component, and will be discussed in greater detail in subsequent "Workout 101" posts. However, there are a few things to keep in mind when designing your primary workout. Most importantly, what is the goal(s) of the workout? For example, you might have general functional goals (e.g., to improve/maintain speed, agility, stamina, balance, coordination, responsiveness, etc.), specific functional goals (e.g., to improve/maintain muscle strength, endurance, or power), mental goals (e.g., to maintain a program consistently, overcome a mental "block", etc.), or structural goals (e.g., to recover from a previous workout or to prepare yourself for future workouts. These elements will be discussed in greater detail in future posts.

The last part of the workout, the cool-down, is much like the warm-up in reverse. It gradually returns your body from its enhanced, exercise-oriented mode to its baseline. Generally speaking, the same activities you do for a warm-up can be done for a cool-down, but consider the following:

Static stretching is better than dynamic stretching at this time. Static stretching capitalizes on the pliability of your now-warm muscles to improve your flexibility safely.

The length of the cool-down is proportional to the intensity of the workout; the higher the intensity, the longer the cool-down. A cool-down should be at least 5 minutes, but it can last as long as you'd like.

When planning a fitness program (and do note that having a plan is a good thing), there are four things you should focus on:

1. Type of activity

2. Frequency

3. Duration

4. Intensity

(Fitness professionals use the mnemonic FITT, Frequency Intensity Time Type.)

These are the four aspects of any fitness program that you can (and should) modify to suit your needs: What type of activity will you be doing (e.g., kung fu, running, weight-lifting, &c.)? How often will you do it (e.g., three times a week)? For how long will you do it (e.g., one hour each time)? How intensely will you do it (e.g., jog, trot, or sprint)?

Why is it important to modify these four aspects?

Varying the type of activity, also known as cross-training, is important for several reasons. First, it allows you to take advantage of the strengths (and minimize the weaknesses) of different activities. Swimming, for example, is fantastic for cardio-pulmonary development but terrible for building strength. Weight-lifting is great for building strength but lousy for training agility. Secondly, cross-training minimizes the risk of injury. Doing the same activity over and over, particularly if it is a highly repetetive activity like cycling or running, increases the risk of repetetive strain injuries and promotes the development of muscle imbalances, which can lead to acute injuries. Thirdly, cross-training helps keep you from becoming bored with your workouts. The psychological aspects of training are often ignored, but one of the most important parts of a fitness program is that it has to be something you want to do. For most people, a certain variety is helpful in this respect. Lastly, cross-training helps to produce more complete fitness. Professional athletes will focus on a particular set of physical skills, but for most of us, general, functional fitness is more useful. Spending three hours a day in a batting cage is important for baseball players, but won't help with most of the activites you do in your daily life. Varying the type of activity you do helps you to become generally fit rather than narrowly talented.

Determining the frequency of activity is largely an issue of time management and organization. First, it is important to schedule at least one rest day per week. At least one day out of every seven should be reserved for rest so that your body can repair the small amounts of damage that occur with exercise and so that you can take a mental break as well. Secondly, you want to distribute your workouts so that they complement each other. For example, if Monday is a really intense weight-lifting session, then don't schedule your second really intense weight-lifting session for Tuesday. Try to spread out your workouts so that there is day-to-day variation in type, duration, and intensity. Lastly, your workouts need to fit within your busy life. If you schedule a hard workout at the end of what you know will be a very busy day, you're a lot less likely to do it. Try to plan your workouts so that they fit comfortably within your schedule, and acknowlege that on some days, it's just not going to happen. Work, family, and other obligations are important; working out should be a source of stress relief, not a cause of stress.

Varying the duration of activity, as with frequency, is largely about time management and organization. If you know you will only have a half an hour one day, for example, that's a better day for a high-intensity workout than for a slow jog. It's also important to consider how much time you will need to get the workout you want. Generally speaking, the cardio-pulmonary benefits of biking for 60 minutes may be achieved in 40 minutes of running or 20 minutes of swimming. Also, if you are new to an activity, you should start with a short duration and gradually increase it over time.

Varying the intensity of activity is largely about the trade-off between training benefits and recovery time. Generally speaking, working out at a higher intensity increases the efficiency of your training (i.e., greater benefits in less time) but also increases the recovery time. Recovery is not the same as rest--recovery can occur during performance of an activity--but it is just as important. Furthermore, some levels of intensity train different abilities better. For example, low-intensity activities tend to be better for training endurance, high-intensity activities tend to be better for training power.

A final note about progression. You will no doubt be unsurprised to learn that you must increase "something" in order to improve your level of fitness. Doing the same things week after week will allow you to maintain your current level of fitness/health but will not help you to improve it. But what do you increase and how? Generally speaking, for any particular type of activity, you should increase first the frequency, then the duration, and lastly the intensity. This will make the transition from easier to harder workouts as smooth as possible and minimize the risk of injury.

 



 

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