Contrary to a popularly-held belief, cardio generally does not burn more calories than weight training.  I say "generally" because so many confounding factors play a part (i.e., duration, intensity, interval training, etc.).  Taking into account the same duration and comparable intensity levels (i.e., METS), weight training burns more calories than cardio.  The primary reason for this is twofold:

1. Weight training promotes muscle mass preservation and growth
2. Muscle is a highly metabolic tissue which stimulates caloric expenditure for up to 36 hours after the weight training session, a condition known as EPOC (Excess Post-exercise Oxygen Consumption).  

BOTTOM LINE:  If you want to burn more calories in order to lean out or lose body weight, be sure to lift the weights!
Note:  Steady-state cardio generally does not cause EPOC although interval and HIIT cardio sessions do cause EPOC.  

     Myths abound and are prevalent in our society because people like to believe in easy, quick fixes for losing weight and gaining muscle mass.  As a result, there is a plethora of products preying on naive consumers in order to make money.  The media is mostly to blame since this is how most people obtain information or misinformation in this case.  
     Many magazine and website editors continually encourage the publication of articles which lack much in the way of factual information and peddle it as new or novel approaches to training or supplementation.  The reality is the information provided is simply a retread of what has already been said countless numbers of times, only written in a different way to make the article seem interesting.  
     But let's not direct all our blame onto the media.  Ignorant consumers who "believe" the newest training routine (e.g., the Insanity Workout, P90X, etc.) is the way to achieve the perfect physique are only deluding themselves and actually encourage unscrupulous salespersons to take advantage of the opportunity to rip us off.  There is nothing magical about these new trends in exercise routines.  If you see it in a late night infomercial, be very wary and view it with a healthy sense of skepticism.  Once again, the name of the game is to separate you from your pocketbook.  
     There is no magic bullet for losing weight or gaining muscle since each individual's body responds uniquely to training stimuli.  The key is to utilize the technique of trial and error in discovering which exercises, sets, reps, rest periods, workout splits, etc. work best for you and you alone.  Just because the big guy in the gym has built a physique worthy of admiration does not mean he knows exactly what works for you to get big.  He may have spent most of his life building his body to what it is today through many years of dedicated and persistent training.  Again, everyone responds differently to exercises, nutrition and supplements.  Supplement and equipment salespersons' main objective is to sale their product no matter if there is a lack of scientific or biomechanical evidence to back up the product.  
     Here are some of the common myths regarding exercise, nutrition and supplementation:

• MYTH:  You can get rid of cellulite by exercising the particular bodypart (e.g., legs).

     Wrong!  Cellulite is caused by fatty deposits and fibrous tissue within the subcutaneous layer of the skin.  Remember the concept of spot reduction being a worthless way to tone certain muscle groups?  The same concept applies here as well.  You cannot tone any muscle and expect cellulite to magically go away.  The body just does not work that way.  Although there is some evidence within the scientific literature indicating that the dimpling caused by cellulite can be temporarily reduced or smoothed out by daily deep tissue massage.              

• MYTH:  You can burn more bodyfat by performing low-intensity cardio (e.g., less than 60% of MHR).

     Low-intensity cardio can be effective in burning bodyfat if performed for long durations (e.g, more than 30 minutes), but interval training can be just as effective in burning an equivalent or more bodyfat in less time.  The key is the amount of total amount of calories burned during the exercise--that is all that matters as far as the body is concerned.  Nutrition is also a big factor in that the body can more efficiently burn bodyfat when there are carbs available.  In other words, fat burning occurs more readily when in the presence of carbs.  So performing cardio while on a low-carb diet is not the best way to burn bodyfat.
  

• MYTH:  Aerobic exercise is the only exercise you need to do to effectively lose weight.

      The optimal exercise prescription is one that recommends the combination of cardio and weight training for losing bodyweight.  The increase in metabolism caused by muscle stimulation and increased lean body mass causes more calories to be expended, which in turn increases weight loss.

• MYTH:  The more you sweat while exercising, the more bodyfat you lose.

       Don't mistake losing bodyweight with losing bodyfat!  They are two completely different animals.  But more to the point, the bodyweight lost is merely water weight and fluctuates throughout the day.  This is why checking your bodyweight before and immediately after working out is only useful for determining how much water you lost and therefore how much you should drink to rehydrate your body.  Actually believing you lost poundage from fat after working out is wishful thinking to put it mildly.  Incidently, any weight lost by wearing a rubber suit or a sweat shirt while exercising will be mostly water weight, not bodyfat.  As soon as you replenish your body with fluids (or food for that matter), those pounds you lost in the gym will return almost as fast as they left.  Of course sweating is indicative of a strenuous workout session and can ultimately lead to weight loss.

• MYTH:  You can burn bodyfat away from specific areas of the body simply by exercising those areas.

      I think by now you know this idea is preposterous.  The phenomenon of "spot reduction" has absolutely no supportive evidence.  

• MYTH:  Your muscles will turn to fat when you stop exercising regularly.

     Let's get this straight:  Muscle tissue is not the same as fat tissue--they are completely distinct body tissues and therefore it is an impossibility for muscle to turn into fat.  But having said this, it is true that muscles will lose size and shape from lack of regular exercise--a process called atrophy wherein muscle tissue is wasted away.  In laymen's terms, "use it or lose it!"

• MYTH:  Losing weight is extremely difficult.

     Actually, losing weight is relatively easy for most people without metabolic problems (e.g., disfunctional thyroid gland).   It's keeping the weight off that's the hard part and what causes weight cycling (and hence yo-yo dieting) in many people.  The diet industry will continue to stay in business because most people cannot maintain their bodyweight.  The solution is simple:  Combine a sensible exercise and complementary nutrition plan to encourage permanent weight loss.  

• MYTH:  If I stay consistent with my workout program I will eventually succeed in my fitness goals.

     
     Unfortunately this is not the case.  If you continue to perform the same workout without progression (e.g., increased loads or sets), you will inevitably continue to get the same results--a condition known as stagnation.  This is where a reputable personal trainer can provide valuable knowledge and expertise in getting you on the right path to achieving your fitness goals.

• MYTH:  Heavy weights make you bigger and lighter weights get you defined (toned).

     The above statement is a myth because it is too simplistic.  In order to gain appreciable muscle mass, relatively heavy weights (e.g., 65 to 75% 1-RM), moderate reps (e.g., 8 to 12 reps), short rest periods (e.g., less than 1 min), and compound exercises incorporating large muscle groups (e.g, squat, deadlift) is what is needed to cause the growth hormone and testosterone release necessary to stimulate appreciable muscle mass.  In order to define the body, relatively light weights (e.g., 50 to 65% 1-RM), high reps (e.g., 15 to 25 reps), and isolation exercises (e.g., leg extension, leg curl) may "tone up" your muscles but at the expense of some muscle being burned in the process.  In order to maintain muscle mass, it's better to continue lifting relatively heavy weights.  Heavy weight training tends to burn fat due to the retention of muscle mass.  A keen nutrition program in conjunction with cardio and heavy weight training is more likely to get you ripped than light weights with high reps.

• MYTH:  Women will become overly muscular when strength training. 
  

     Testosterone levels largely determine one's gain in muscle mass from training.  Studies have shown that women produce only about 10 percent of the testosterone that men produce, which significantly reduces their potential to gain considerable muscle size. On the other hand, women should perform strength training to at least maintain a lean physique.  Strength training improves body composition by reducing fat mass while increasing lean body mass (i.e., muscle).  Bottom line:  women should train no differently than men when it comes to strength training.  Thus, squats, bench presses, deadlifts, pull-ups, pushups, etc. are exercises all women should perform to look sexy and strong!  

• MYTH:  If you don't feel sore the day after a workout, you haven't worked out hard enough.

      Feeling sore, an indication of what's known as delayed onset muscle soreness (DOMS), is not required in order to gain muscle mass, tone up, etc.  What's important is that your workout is productive and intense enough to stimulate more strength in your muscle tissue, nerves and bones.

• MYTH:  Performing crunches will flatten my stomach.

      If this were true, shouldn't there be more people sporting flat stomachs in the world?  If seems everywhere you look in the gym, you'll see somebody doing abdominal crunches--it's a ubiquitous exercise for sure.   Unfortunately, the reality is crunches do not flatten the stomach.  Instead, the exercise will help to strengthen your core muscles (e.g., rectus abdominus) under that layer of fat tissue called subcutaneous fat.  In other words, crunches will get your abs stronger but will not burn your belly fat (see the spot reduction myth above).  A healthy, clean nutrition plan will help to reduce the fat around your midsection and allow your hard-earned six-pack to appear.  

• MYTH:  Cardio burns muscle.
  

     This myth most likely got started when physique competitors began eating less food (i.e., low carbs) while doing cardio in an effort to lean out.   It's not the cardio that is the culprit but rather caloric intake that's really at issue here.  Of course cardio may become a factor when it is performed for over an hour every day of the week.  But in most cases, the decrease in muscle mass is more likely to be attributed to not eating enough food to accommodate the hard training.   Adequate protein (i.e., whey protein shakes post-workout) is especially crucial to maintain muscle mass when caloric intake decreases.  

• MYTH:  Eating soy protein can have estrogen-like effects on the body.

     This myth got started from a study which indicated eating soy may increase estrogen within the body.  But all of the hoopla needs to be taken down many notches because the amount of soy needed for this to happen was not emphasized.  In other words, one would have to eat large amounts of soy protein every day for estrogen levels to increase.  Most people don't eat nearly enough soy for this to occur.

•  MYTH:  I cannot get lean because of genetic limitations.
  

      This provides an easy excuse for why you're not losing bodyfat.  It takes hard work, dedication, discipline, and most of all, consistency when it comes to leaning out.  Your nutrition, cardio and weight training needs to be well-planned and adhered to in order for progress to be made.  We all have the capacity to accomplish our fitness goals but the key is hard work and some sacrifice to get there.

• MYTH:  Weight loss means fat loss on the body.

       This myth will not die!  Weight loss should never be confused with fat loss.  The weight scale only displays body weight, not fat weight.  I'm always entertained by many gym goers who weigh themselves before and after weight training.   They believe by what the scale shows that they're losing fat weight when in reality they're losing water weight.  There's no way you can burn an appreciable amount of bodyfat from just one training session but you can become dehydrated and therefore lose water weight.  I bet the same people who believe you can burn bodyfat from each training session also believe you can accelerate the fat burning process by wearing a sweatshirt while working out.  Please!  Again, the weight lost is water weight, not fat weight.  The best way to ascertain whether or not you're burning bodyfat is to perform a skinfold assessment or simply look in the mirror.  The mirror does not lie.  How you look tells the story.  

• MYTH:  Eating "low-fat" or "fat-free" foods is a great way to lean out and get ripped.

        Ah, if only it was this easy--everyone would have ripped abs for the summer if this was true!  The reality is that eating foods labeled as "low-fat" or "fat-free" may actually make you fatter.  Why?  Because these foods tend to have more sugar, salt, preservatives, and chemicals than regular foods in order to make them as palatable and to increase shelf life.  Remember fat makes food tasty and rich.  The manufacturers are compelled to add sugar and sodium to "low-fat" and "fat-free" foods to sell their products.  Unfortunately, high carbs (from added sugar) and excess sodium (from added salt) wreak havoc on a lean diet.  Highly processed foods may actually reduce one's metabolism when consumed regularly and make the process of leaning out even harder.  Instead, eat a cheat meal at least once per week  to satisfy your craving for sweet or fattening foods.  This way, you'll less likely want to overindulge in decadent foods.