The wide range of elaborate athletic watches strapped to the wrists of runners, cyclists, swimmers, and even those working out in the gym is a testament to the preoccupation of time amongst athletes. They are utilized to time workouts, pace a run, aid in cutting off a couple minutes to achieve a personal record, or even determining when one will get to quit working out and go home. Thus, it is evident that while training, time is clearly on the mind. This should also be the case when coordinating your meals and snacks in order to maximize your workouts.
If you fast before your event you could impair your performance 
by depleting energy, stored as glycogen, in your liver that your body needs for aerobic exercise. If you eat carbohydrate too close to your event you raise your blood sugar and signal your body to release insulin which leaves you with low blood sugar and causes your workout to take a hit. This also hinders the release of energy from your liver. Both circumstances can lead to muscle degradation, lack of energy, and consequently the proverbial ‘hitting of the wall’ which I’m sure we have all experienced at one time or another (I know I have).
So to exploit your grub to the fullest choose low fat, low fiber foods, medium to low glycemic index carbohydrates, moderate protein, and plenty of fluids several hours or so prior to your workout. This will allow your body time to clear your gut of its contents so you can avoid cramping up while allowing for fluid absorption for hydration, maintaining an appropriate level of blood sugar, and preserving glycogen stores which are all integral components of achieving the most out of your workout.
For endurance athletes (>90 minutes), those in extreme environments (extreme heat, cold, or altitude), or those with long intense interval training workouts, eating additional carbohydrates throughout the workout can prevent hitting the wall during a workout over one hour by maintaining blood sugar levels.
It is also important to refuel the body within thirty minutes to one hour post workout. This is because the stores of energy (glycogen) in the muscles are low because the body was feeding off of that energy. As a result, the muscles are more willing to replenish those stores with as much energy as possible. Eating a carbohydrate rich snack or meal within thirty minutes to one hour
of exercise can provide the muscles with the energy it needs and will help fuel the next workout while aiding an athlete in meeting their daily needs. It is also important to add protein to the post workout snack or meal to enhance muscle protein building and repair. Great post workout snacks such as peanut butter smeared on a slice of our freshly milled and freshly baked 100% whole grain bread or a glass of chocolate milk are not only carbohydrate rich but also protein rich as well (not to mention they provide phytochemicals and essential vitamins and minerals). Eating small amounts of protein shortly before exercise can also aid in this as well.
When do you like to work out? When do you like to fuel up?
*Remember, individual needs vary person to person. Find what you can personally tolerate and what meets your needs to sustain energy and a healthy body weight. Consult with your physician to determine an appropriate level of physical activity and/or your dietitian to further assess your individual needs.
