Does Morning Cardio Burn More Fat?

This is interesting I am going to keep an eye on this topic.

I'm used to hearing this from trainers too. The theory is that if you exercise on an empty stomach, your body has no carbs to burn so it goes for fat. However, the second energy source in your body is protein, so you could actually be breaking down lean muscle to fuel your workout.

Seems plausible, however it goes against everything I'm learning in school to become an Athletic Trainer and Sports Nutritionist.

It goes both ways. In the morning your metabolism and body temp are low. Exercising in the morning revs them up for breakfast and maybe even lunch. At the same time doing cardio toward the evening revs it up for dinner, usually the largest meal. Personally I go with both. I do half an hour in the morning and half before dinner. Metabolisms up most of the day and I've seen many reports that say doing say 30 mins twice a day is better than an hour once a day. I also drink a glass of ice water in the morning, the body needs to warm up the core temp because of the water so it has to raise the metabolism. It's hard but 10lbs in 3 weeks doesn't lie.

The biggest mistake that people make in discussing these topics is that they think of a workout as a discrete event unrelated to what occurs the other 23 hours of the day, 7 days a week, etc. Metabolism is an ongoing process and the body is constantly using a mixture of fuel substrates.

The main factor that drives permanent fat loss is maintaining a consistent negative calorie balance. The fuel substrate burned during exercise has no independent effect on fat loss.

So there are conditions under which the body will burn a higher percentage of fat as fuel during a workout, including some workouts done in the "fasted" state. However, not only is the amount of fat burned miniscule (less than an ounce under optimal conditions), the body regulates fat oxidation the rest of the day so that at the end of 24 hrs, there is no difference.

In other words, if you do a workout which burns 50% or 60% of the calories from fat vs one the burns 30%-40% from fat, the body adjusts fat oxidation the rest of the day--so that at the end of 24 hours total fat oxidation is equal (and small).

A beginning exerciser can make substantial gains in fitness in a relatively short period of time which will far, far, far outstrip any trivial differences that might occur as a result of things like exercise timing, meal timing, meal frequency, workout sequence (cardio or weights first), supplements, etc.

That is why people starting a program should focus on basics and not waste effort or energy on these peripheral issues. Things like maintaining a focused, appropriate intensity level, adding 10 min to average workout time, adding an extra day to your routine, maintaining a consistent frequency of exercise--these things will help you improve and lose weight more than all the peripheral concerns combined--by a huge margin.

If you haven't eaten in the morning before you workout you will most likely burn muscle for fuel. Not good!

When glycogen is depleted (in the morning) or when you don't get enough calories, your body burns muscle first. When a marathon runner or triathlete takes a drink during competition it is not water. It is fuel, mostly glucose and some protein. Why? they burnt all their glycogen off and they will start wasting muscle. Glycogen depletion happens in about 60-90 minutes of intense exertion defined by heart rate. It also happens over night why you sleep. If runners and triathletes re-fuel when glycogen depleted, why would you wake up glycogen depleted and workout before restoring it?

Most of your glycogen is stored in your muscle, then blood, then liver.

Do the smart thing. Make sure you are fueled for your workouts and make sure you replenish your fuel afterwords. Best time to refuel is 30-60 minutes after completion. The sooner the better.