Is your workout making you fat?

Lately, I have been bombarded with calls and emails from women and men, who are doing tons of cardio AND gaining weight! Correct, they are doing loads of cardio exercise (1-3 hours day) and are gaining, not losing weight.

Is this possible? My first thought is, perhaps they are simply gaining muscle? Well, maybe? However, if they are doing tons of cardio, trust me when I tell you, this is NOT an anabolic workout (a muscle-building workout) this is a catabolic workout (a muscle-breakdown workout). Thus, a high amount of cardio usually results in muscle loss, not muscle gain. Have you ever seen a really muscular marathon runner? I certainly have not. Most elite marathon runners look emaciated. They are super lean yet have very little muscle. You see, long distance endurance activities are very catabolic. They end up breaking down muscle — not building it.

Over time, this means:

Lots of cardio=catabolism=Less muscle = lower metabolism = Fat gain

Most people think the opposite:

Lots of cardio = more calories burned = weight loss

Shouldn’t this be the right equation? Well, it would be, however, you are leaving out one very important component — hormones.

Lots of cardio = elevated cortisol, decreased T3 (active thyroid), and increased estrogen (fat storing hormone) = Muscle breakdown + lower thyroid function = FAT gain and muscle loss.

Is it really possible to gain fat while doing tons of exercise?

Yes. Here is what is really going. After about an hour of exercise, your cortisol levels increase and stay elevated until you have finished your extended cardio workout. Cortisol is a major body stress hormone. Exercise is stress. Thus, long duration exercise elevates cortisol for extended periods of time. Elevated cortisol is very catabolic, it breaks tissue down. Once your glycogen stores (long-chain sugar stored in the muscles) are used up, cortisol starts to mobilize (burn) not only fat, but also other tissues: muscle, organ, and bone. The longer your workout session, the longer cortisol stays elevated, the more tissue breakdown can occur.

In addition, about 30-45 minutes after you start your workout your thyroid hormones plummet.  The thyroid senses the bodies increased metabolic needs so it starts slowing many metabolic processes down (immune system, hormones, digestion) to conserve energy.  As thyroid drops, the stress hormones rise so the body can start using its own energy stores (fat, muscle, tissue).

Now, don’t get me wrong — initially the long cardio sessions will help you lose “weight”, since you will be burning fat (AND burning some muscle). But at what cost?  The cost of valuable muscle, bone, and tissue?

You are losing muscle, so your Basal Metabolic Rate (BMR/how many calories your body will burn at rest) drops. Although you are burning many calories during your extended workout, you actually start to burn fewer calories while you are not working out.   Which long term means less calories burned in any given day.

Your body starts to adjusts to the longer workouts by becoming more efficient.  Which means an increase endurance fitness level, but an overall slower metabolic rate at rest. Eventually, you find you have to workout even longer to burn the same amount of calories — or you start gaining fat again. Does this sound like something you may be going through? Do you feel you have to work out longer to stay thin — or if you miss a workout the fat and weight gain is a really fast process?

To make matters worse, like I said above, without proper nutrition, during your long cardio sessions, your active form of thyroid (T3) plummets. T3 needs sugar to work properly. If you utilize all your body’s stored sugar (glycogen) for exercise and do not replenish these stored glycogen stores, T4 stops being converted to T3 in you liver. Once T3 can not be converted, your metabolism slows and your body then releases more cortisol and the cycle continues.

If your workout is making you fat…

Here are 10 things you can do to make sure you will be losing fat — not gaining — in your workout:

  1. Shorter workouts: Keep your workout sessions under 60 minutes — especially if you are a beginner.
  2. Lift: Engage in weight training to build muscle, which will increase your metabolism.
  3. HIIT: Try high intensity interval training (20-30 min workouts that are short but very intense).
  4. Eat right: If you want to train for an endurance event, make sure your nutrition is in check. It is imperative to eat the right combination of carbs, protein, and fats before, during, and after the workout to help replenish your glycogen (sugar) stores and keep your metabolism working optimally.
  5. Intensity: Work harder — not longer. Stop using long cardio sessions as a way to lose fat. Longterm, it does not work.
  6. Sleep: Get plenty of REST to help your metabolism heal.
  7. No dieting: If you are dieting while doing long cardio sessions…STOP immediately, this is killing your metabolism even more!
  8. Essential nutrients: A good diet will contain all your vitamins and minerals.  ONLY take supplement if food is not available to meet mineral and vitamin needs.
  9. Ask for help: If none of this works, or you are a little confused, ask an expert for help.
  10. Patience.  Healthy fat loss takes time, and commitment.

Do yourself a favor — allow your body to start working for you, not against you.

Get off the cardio wheel of insanity. There are far better methods for long term fat loss and leanness.

Your Optimal Health Coach,


* I do want to make a side note that there are many competitive, endurance athletes out there that are lean, muscular and fit. However, 99% of these athletes have never used their sport as a weight loss tool. They workout to compete NOT to lose fat. They eat five to ten thousand calories a day to support their metabolism and all their activity. They train at a very high aerobic threshold, usually 80-85% of their max heart rate, their sport is their life, yet trust me, if they ever stop…they will gain fat!