time gap

Question
Hi,

I was curious to know how much time gap is recommended between your meal and your exercise routine.
case 1. if you are going to exercise after breakfast. How much time after your breakfast ?
case 2. if you are going to exercise after lunch. How much time after your lunch ?
case 3. if you are going to exercise after dinner. How much time after your dinner ?

Also, I was wondering that how much time should one wait after the exercise and then eat something.
case 1. how much time should one wait after the exercise and have breakfast ?
case 2. how much time should one wait after the exercise and have lunch ?
case 3. how much time should one wait after the exercise and have dinner ?

thanks.

Anil

Answer
Hi Anil,
Thanks for your question.  Lets start with some physiology that will help make sense of my time recommendations.  The body stores food as glycogen in the liver.  The liver is about a 3 pound organ that is capable of holding 300 calories of digested food.  During typical daily activity the average human burns 100 calories per hour.  So, in 3 hours our body will have burned off the glycogen stores in our liver.  At this point our body begins to switch from utilizing glycogen to utilizing stored body fat.  This is the point at which we want to turn up the energy output (via exercise) to maximize fat loss.  

So, to answer your first question, in all three cases you would want to wait three hours after eating before exercising.  If you eat and then immediately exercise your body will be utilizing the food you just ate for energy and thus will not be tapping into your stored body fat.  This is why I can go to the gym and make significant changes in my body while others look the same month after month.  They are only burning the food they ate and never getting into their body fat.   Now, this assumes that your goal with the exercise is removal of body fat.  If you are wanting to build muscle or improve performance this is not the ideal time, and I can explain further if you you would like.

To answer your second question of how much time to wait after exercising before eating, we must go back to the body's physiology.  When you begin an exercise session your metabolic rate is low.  Within a few minutes it begins to rev up and will continue to climb to meet the demands of the exercise.  The more intense the exercise, the more demand for energy by the muscles and lungs.
When you finish exercising your metabolism does not drop straight back down, but rather, takes time to return back to a baseline level.  This process takes about 60 minutes (depending upon the intensity of the workout of course).

Now, lets say that you waited 3 hours after eating to workout.  Your entire workout you were utilizing stored body fat for energy.  If you were to wait an additional 30 minutes after your workout before eating, what would your body be using for energy during that time?  Stored body fat!  And it is using it at a high level because your metabolism is still quite high from the workout.  If you wait 60 minutes after your workout to eat then your body will be using stored body fat that entire time.  

I would not recommend going beyond 60 minutes as your body will begin to sense starvation and will respond by lowering your metabolism to conserve energy - not something we want to have happen.  I personally wait 30 minutes, as this is when the metabolism is the highest.  It is like getting a bonus 30 minutes of fat burning after every exercise session.  This has really been the secret for the way I am able to get so lean so quickly.

Give this a try and let me know how it works.  And please feel free to let me know if I can clarify anything, or if you are utilizing the exercise for a goal other than fat loss.

best of health,
Dr. Bret

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