Dear Dr. Bell,
I was told to always do cardio before breakfast for the session to be most effective, is this correct? Does it really make a difference? I would love for you to weigh-in.
I prefer to workout before breakfast and have trained my body to do that! Cortisol levels are highest when you wake-up and provide extra energy for your exercise. If you ate adequate Complex carbohydrates, protein and essential fatty acids the day prior, you will have sufficient stores for a hard workout. Some people prefer to workout after breakfast. If you do, you will need to wait 2-3 hours post eating before starting to exercise.
Breakfast is a meal and any meal will produce physiological effects that are not conducive to exercise.
You have a limited blood supply. The three areas of the body that require the most blood flow are the brain, your muscles and your digestive system. When you begin to exercise immediately after eating a meal, you will start a conflict within the body on where to prioritize blood flow. The more you have eaten, the more blood is needed for digestion. Similarly, the longer and harder you exercise, the greater the demand of blood flow will be to your working muscles.
Another problem is your endocrine system is conflicted in aiding digestion and your muscles. The insulin response to your eating will result in less total energy available for exercise activity. Other physiological responses to eating also conflict with physical activity.
Therefore, it is recommend that you wait 2 hours after meal consumption to begin exercise or 3 hours after a particularly big meal.
Supplements such as BCAAs or Protein Shakes in liquid forms leave the system rapidly so you need little delay before exercise, typically 15-20 minutes. Coffee will typically kick in to boost energy when consumed 15-30 minutes prior to a workout. If you add cream and sugar to your coffee, don’t worry. Most studies indicate that calorie intake under 200 calories does not result in an insulin response. Post-Exercise, you want to have a source of fast-acting protein and carbohydrate as quickly as possible when your session ends. If you wait 2 hours past excise like the old recommendation, you risk unwanted Ketosis at worst or miss an opportunity to initiate muscular anabolism at best. Recovery and adaptation begin when your body has the nutrients readily available for building and repair.
I recommend a Protein supplement with carbs before and after workouts. Post workout Protein with simple carbs are best. Researches have seen great results with Chocolate Milk.