Why Cardio Is Not Your Answer to Weight Loss!

Skeleton on Treadmill   by Maren Sederquist, MES, CSCS, CPT 

Have you ever noticed the person who’s been in the gym on the elliptical trainer for an hour, 5 or 6 days a week, and doesn’t look any different than they did a year ago?

Have you ever seen the person who’s been doing the same aerobic exercise for a decade, but they’re actually gaining weight?

Have you ever known that person who’s been training for a marathon and steadily increasing their mileage, but they’re not losing any weight? Or at least not any more than the little bit they did right in the beginning of their training program?

Or maybe that is you?! 

Whether any of the above examples are you, or you just want to prevent them from being you, read on! 

Numerous studies published over the last few years show overwhelming evidence disproving the myth that steady state cardiovascular exercise is the answer to weight loss.

“But, wait!” you say. “I’ve done it before!” The first time you wanted to lose weight, all you did is start adding some cardio in, and you lost weight. The second time you didn’t lose weight as quickly or as much, but you did lose some. The third time, not so much. Hmmmm… Your real red flag should be that you had to try it again! If your weight loss plan was a success, you should be able to maintain the changes you made and keep the weight off. ”But it worked before, why isn’t it working again?!”

I’ll tell you why… 

Cardiovascular exercise is catabolic. That means it breaks down muscle. When you first start a cardiovascular exercise program you might initially build the little bit of muscle that is needed to perform the exercise, and you burn calories you weren't before, during the session. Then, very quickly, your body adapts to the exercise - and your body works efficiently, using as little energy as possible to complete the task. Pretty soon, you're burning less calories for each cardio session, but you're still eating as much as you were when you increased the exercise. The only solution is to then eat less, or add more cardio to see some results again. Since we're all limited in the amount of time we can spend exercising each day, and we don't want to put ourselves at risk of injury by exercising too much, that's not a good solution!

Another myth is that cardio exercise should be done at low intensity so you're in a "fat burning zone". While it's true that you burn a larger percentage of fat at lower intensities - in fact the lowest percentage while you're resting! - you burn more total calories, and therefore more calories from fat, at higher intensities. Your body never uses one fuel at a time for energy anyway. At any given time it may burning glucose, glycogen, fat or even muscle to provide it with the energy it needs. Exercising in a fat burning zone will just keep you burning less calories.

More importantly, doing cardio exercise at a low intensity will do nothing for your EPOC (Excess Post-Exercise Oxygen Consumption). Defined as the “recovery of metabolic rate back to pre-exercise levels” it “can require several minutes for light exercise and several hours for hard intervals.” Why not take advantage of EPOC to burn more calories after you're done exercising?!

Is steady state cardio exercise good for your heart and other organs? Absolutely! But so is losing weight. And the methods of exercise I’m going to teach you about are going to do both!

Studies are showing

  • Steady state cardiovascular exercise adds next to nothing toward weight loss when added to dieting.
  • Time spent on interval training creates more fat loss than twice as much time spent on steady state cardio. You burn more calories all day afterwards. And it builds muscle, boosting your metabolism.
  • Strength training by itself creates more fat loss than steady state cardio by itself.
  • Proper nutrition is more important than exercise for weight loss, but strength training and interval training will help get more weight off and keep it off!

Here is some of the specific research

  • In a 3 month study, women exercised at 78% of their max heart rate for 45 minutes, 5 days a week and lost no more weight than those who dieted alone!
    Utter AC, Nieman DC, Shannonhouse EM, Butterworth DE, Nieman CN, Influence of diet and/or exercise on body composition and cardiorespiratory fitness in obese women. Int J Sport Nutr. 1998 Sep;8(3):213-22.
  • In a 6 month study, subjects did 50 minutes of cardiovascular exercise 5 days a week, and lost no more weight than those who dieted only.
    Redman et al. Effect of calorie restriction with or without exercise on body composition and fat distribution. J Clin Endocrinol Metab. 2007 Jan 2.
  • In a 12 month study, subjects did aerobic exercise for 60 minutes a day, 6 days a week, and only lost an average of 3.5 pounds for the whole year!
    McTiernan et al. Exercise Effect on Weight and Body Fat in Men and Women. Obesity 2007 June - 15:1496-1512.
  • In another study, 20 weeks of endurance training cost subjects 28,861 calories, while 15 weeks of interval training caused subjects to burn 13,614 calories, yet the interval training subjects showed 9 TIMES greater subcutaneous fat loss (when corrected for energy cost) that the endurance group.
    Tremblay A, Simoneau JA, Bouchard C. Impact of exercise intensity on body fatness and skeletal muscle metabolism. Metabolism. 1994 Jul;43(7):814-8.
  • Another study compared 3 times a week training for 15 weeks, 20 minutes of interval training vs. 40 minutes of steady state training. Both groups ate the same. The interval training group lost 5.5 pounds of body fat and increased lean mass. The steady state actually gained an average of 1 pound of fat!
    Trapp EG, Chisholm DJ, Freund J, Boutcher SH. The effects of high-intensity intermittent exercise training on fat loss and fasting insulin levels of young women. Int J Obes (Lond). 2008 Jan 15.
  • This strength training group lost significantly more fat and maintained more muscle than the aerobic training group.
    Geliebter A, Maher MM,  Gerace L, Gutin B, Heymsfield SB, Hashim SA. Effects of strength or aerobic training on body composition, resting metabolic rate, and peak oxygen consumption in obese dieting subjects. Am J Clin Nutr. 1997 Sep;66(3):557-63.
  • In a 12 week study of 3 groups: diet only, diet plus aerobics (5 times a week, progressing from 30 mins to 50 mins) and diet plus aerobics plus weight training. Diet group lost 14.6 pounds of fat, diet plus aerobics lost 15.6 pounds, and diet plus aerobics plus weights lost 21.1 pounds of fat (44% and 35% more than the other groups, respectively).
    Kramer, Volek et al. Influence of exercise training on physiological and performance changes with weight loss in men. Med. Sci. Sports Exerc., Vol. 31, No. 9, pp. 1320-1329, 1999.
  • In a low calorie dieting study, those who added resistance training prevented lean body mass and increased their metabolism while they lost fat, whereas a dieting and aerobic exercise group lost lean body mass and decreased their metabolism.
    Bryner RW, Ullrich IH, Sauers J, Donley D, Hornsby G, Kolar M, Yeater R. Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate. J Am Coll Nutr. 1999 Apr;18(2):115-21.
  • A study showed strength training done in a circuit training protocol with 4 sets of only 3 exercises done for 10 reps each - taking 31 minutes - elevated calories burned for the next 38 hours.
    Schuenke MD, Mikat RP, McBride JM. Effect of an acute period of resistance exercise on excess post-exercise oxygen consumption: implications for body mass management. Eur J Appl Physiol. 2002 Mar;86(5):411-7. Epub 2002 Jan 29.

What You Should Do

Since everyone has a limited amount of time each week, it's important to prioritize what you spend your time on. In order of priority, here's how you can best spend your time if you have a weight loss (or maintenance) goal. Only go onto the next number if youy've taken care of the preceeding ones.

 1. Use correct nutrition. NONE of the above matters without the right nutrition. You can destroy your week’s worth of workouts if you’re not eating in a way to support your efforts. How should you eat? Start here.

2. Do "metabolic" resistance training. It burns lots of calories for the session and for an extended time afterwards, and builds the muscle that elevates your metabolism. Best results are with 3-times-a-week programs.

3. Do interval training. The higher intensity will keep your body burning more calories and fat after your workout. Once or twice a week is all you need.

4. Do higher intensity steady state cardio training. The higher intensity will keep your body burning more calories and fat after your workout. The point here is that low intensity won't help much with weight loss. Only add one more per week if you have time.

5. Do any other activity. This is where your steady state cardio comes in. IF you have time in your week after you've taken care of your higher priority exercise, by all means do some more, and enjoy it. :-) Doing too much high intensity exercise will depress your immune system. You need rest after all your hard work for the week!

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