Exercising for long periods or doing high-intensity workouts with no intake of food for long duration can lead to low blood sugar and fatigue.
The adversity one can go through with no or less intake of food before a workout can be classified into short and long term effects
Short term -
Exercising for long periods or doing high-intensity workouts with no intake of food for long duration can lead to low blood sugar and fatigue. Your body uses carbohydrates as a main fuel source for workouts, and if you do not have enough carbs stored in your body which comes from the foods you eat, your body will start burning the stored fats.
However, if your diet is severely restricted, your body will burn muscle tissue and even organ tissue to create energy, which can cause lossof muscle mass, fatigued and can develop into long term health problems.
If you have nourished your body over a long period of time, months of years, it may go into starvation mode, burning body tissues for energy and holding onto any calories you consume to keep your basic systems running. Starvation mode makes it hard to lose weight and poses serious health risks such as bone loss, irregular heart rhythms and even heart attacks.
The size and timing and the content of your pre- and post-exercise meals and snacks plays an important role for your energy levels during workout. Here’s what you need to eat and drink to get the results you want! How well your body recovers and rebuilds after your workout, and whether the calories that you consume will be used as fuel or stored as fat.
Your Pre-Exercise Fluid Needs
Being well hydrated will make your exercise easier and more effective. Try to drink 16-20 ounces of water during the 1-2 hours before starting your workout.
Most of the fuel you use during exercise doesn’t come from the food you’ve recently eaten! It actually comes from the carbohydrates (called “glycogen”) and fat that’s stored in your muscles, liver, and fat cells. That’s enough to fuel 1-2 hours of very intense exercise or 3-4 hours of moderate intensity exercise.