To eat or not to eat before a workout, shall you consume a sports drink during and what shall you eat afterwards?
Nothing. That is the simple answer.
Let me explain.
The goal for most people of the exercise is to stimulate metabolism to then tap into the fat reserves, resulting in weight loss, as well as building muscles.
When you exercise, you induce a stress event that breaks down your muscles, which burns up sugar (glycogen) in the muscles, then tap into body fat and finally, your body is going into recovery mode. During the recovery process is where your digestion is occurring and where your body is building back up. Many trainers and nutritionists say we need to eat before the workout for energy and after eat after to replace your glycogen stores and consume protein so your body can build more muscle mass. But what is the optimal way for fat loss and muscle building?
What is a glycogen reserve?
Glycogen is the storage of sugar/glucose in your muscles and in your liver. The body works in a way that we have to burn off all the sugar/glycogen stores before it taps into the fat. Now, why would you eat or drink anything during or after work out if the goal is to burn fat?
So, in reality, if you eat during the exercise you are going to slow down the benefits of weight loss and muscle building.
But what about protein shakes?
Now, we need protein to build muscle mass. This is a fact. But it will take 24 hours, if not longer for that protein shake to be digested, go through your liver and end up in your muscles. It’s the meal that you ate the day before that is going into the muscles. As well, if your liver is overloaded with too much protein, it won't end up in your muscles. Our body does very well to build muscle mass if your liver is healthy and you don't overload it and you have all the trace minerals that help with the building of the muscle.
The sports meal replacement industry is a multi-billion dollar industry. Why have we been told by protein supplement businesses that we need a protein shake within 30 minutes after a workout, or our body won't have a chance to build muscles efficiently. Is this a marketing scam? Yes.
The other thing is that if you were going to eat or drink something that is highly concentrated in protein, such as whey protein it will trigger insulin. Insulin has a profound effect on both protein and lipid (fat) metabolism. What does insulin do? It stops fat from burning completely and stimulates the liver to store glycogen. In other words, each time you are consuming whey protein you are actually raising insulin - in fact, every time you eat you stimulate insulin.
The bottom line
Exercise stimulates growth hormone that's the main fat burning hormone, if you eat foods or drinks high in sugar/carbohydrate or protein it will spike insulin and block the growth hormone. Which will not give you the effect of fat loss or muscles building.
The benefit of exercise actually occurs 24-48 hours after your workout, especially in your sleep. So the key points are to get better sleep and not eat before, during or after a workout.
But there are some exceptions:
If you're an athlete or work out twice a day
If you're a bodybuilder
If you're training for a marathon or do long-distance running
If you are a diabetic and have blood sugar fluctuations
So, if you’re not doing extreme exercise or are planning to do some serious muscle building. My recommendation would be to eat 1.5 hours before exercise and wait 30-60 minutes (or longer after exercise before eating.
http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/pancreas/insulin_phys.html\
https://www.sciencedaily.com/releases/2017/04/170406152651.htm