There is a lot of information out there about what to eat before, during and after exercise. Much of what is published is done so by companies trying to sell products, many of these products are great, while some of them are terrible and full of chemicals. In this post there will be an attempt made to describe what you should be eating and when with regards to exercise.
It is important to note that how people fuel is very individualized. There is no substitution for experimentation. Make sure that you try a few different things to figure out what works best for you!
“Pre workout” is a very broad term. The general rule of thumb is that as you move closer to your workout your intake should get less and less and move towards simple carbohydrates. If you are:
The day before your average workout you should eat as you normally do, unless you normally eat fast food in which case STOP and eat something healthy. If you are the night before an event you should be eating a carbohydrate based meal that consists of primarily complex carbohydrates (brown rice, multigrain pasta, quinoa etc..). Most events will have a big pasta dinner the night before for all the competitors, but this is something that you will want to attend at your discretion. Often the day before a big event you should stick to things you know and cook yourself to minimize the chance of any gastrointestinal issues on race day.
2 or more hours away from your workout: you want to eat a whole meal. Preferably a balanced full meal consisting of primarily carbohydrates (50-60%), but also including some proteins and fats.
1 hour away from your workout: At this point you should be eating simpler carbohydrates. This can consist of fruits, seeds, nuts, juice or a meal replacement bar of some kind (preferably something healthy!).
30 minutes or less away from your workout: Now you are in pre workout mode. Either driving to the gym, trail, track etc... and if you need to eat at this point you are probably in a rush and did not have time to eat earlier. Simple carbs are key here and should only consist of things that will break down in your body quickly. A good rule of thumb is juicy fruits! Mangoes, pears, grapes, raspberries, oranges and pomegranates make great pre workout snacks.
There are many pre workout products out there and many of them contain stimulants. The stimulant varies from caffeine to ginseng, but they all have the same goal, which is to get you excited before your workout. Very few of these products are actually beneficial to the workout itself and can often have negative effects; however many people like to use them to get themselves psyched for what is to come.
60 minutes or less: you don’t need to consume anything during a short workout except water. If you have eaten properly throughout the day then your body has enough stored carbohydrate to get you through a hard 60 minutes.
Over 60 minutes: your bodies store of carbohydrates will be depleted after about an hour of hard work. It is important to make sure that if you are planning on continuing on beyond this point that you are fueling. Again this is going to consist of primarily simple easy to digest carbohydrates. While your body is working at a high level your digestive system slows dramatically to save energy for your muscles; therefore if you eat anything heavy or hard to digest while your exercising you will most likely not feel very good and the food will simply sit in your stomach and take up space!
Eating for endurance sports is very individualized and there are numerous products out there. These products are usually gels, drinks, bars or chomps (candy like substance that is usually full of quick burning carbohydrates). Again it is very important to experiment with different things before committing to one or another. A general rule to follow is consuming 3-400 calories per hour of exercise. This will leave you in a calorie deficit for the event, but will maintain your ability to work at a high level for a long time.
What to eat after a workout is the most debated subject in this topic, but the research is fairly conclusive in that the 20-30 minute window after exercise your body is trying to restore the muscle glycogen that it has lost, therefore the best thing to eat after your workout is carbohydrates. Most people that will argue this point will say that you need protein. While it is true that protein is the building block of all cells and is necessary for muscular recovery, the window immediately following workouts is a time for carbohydrates. Protein is not a bad thing to have after a workout, but it is not what is required for immediate recovery.
Longer than an hour or two after a workout your body will start to catabolize and break down muscle tissue if there is not enough substrate (food) for it to break down and use to facilitate the cellular repair. It is essential that you eat a full meal (or have a meal replacement type drink) within 90 minutes of your workout. This will decrease muscle soreness and increase muscular recovery.
All of the above information is based on the current working theories of exercise physiology. There are movements that swear by one trick or another, but the bottom line is that the above method is tried, tested and true and works very well for the vast majority of people. Experimentation is key due to our individual differences and tastes. Use the above as a general guideline to work from and you will be on the right track!