You may be skilled, but can't run the full 90 minutes. Or you're fit and skilled, but don't know how to counterattack or ... you get the picture. Most coaches like teaching skill and tactics, but the fitness part can be perplexing.
This game requires most aspects of fitness; endurance, speed, power, strength, etc. You know I think endurance is very important. But just running three to four miles at a good pace is not soccer-specific endurance.
Soccer has many aerobic periods (walking and jogging) as well as periods where aerobic energy isn't coming fast enough, causing you to add energy anaerobically, which makes you tired. We tend to neglect an important aerobic period: recovery from higher-intensity exercise.
In my opinion, the key to physical performance in soccer is your ability to recover quickly from one run so you can run again, sooner or at a faster pace than your opponent the next time you have to run. Plus, games may be scheduled less than 48 hours apart, so you have to recover from the first game to be ready to play the next game. This is the first of a three-part series on recovery.
The game is repeated short bursts of hard activity broken up by periods of lower-intensity running and standing. When you walk or jog, energy comes from the use of oxygen metabolizing fats and carbohydrates (glucose and glycogen) into waste products of carbon dioxide and water. These are handled easily by the body. When you increase the speed of running to a cruise, sprint, or when dribbling (the most intense part of the game), you add energy from the anaerobic metabolism of glucose/glycogen.
The problem is the waste product -- lactic acid. Once lactic acid is produced, the body has to get rid of it, and this is done during recovery while running slower, walking or while standing. During reduced intensity work, you still inhale lots of oxygen -- the more oxygen your lactic-acid-filled muscles can use (a training adaptation), the faster the lactic acid is eliminated. Therefore, to teach the body to learn to recover fast, you must train to recover.
This is done by playing games that have restrictions that force intensity and limit recovery: small sided games (e.g. 4v4) with restrictions to force running, lots of ball contact and minimal rest. 11 v 11 games at practice are not intense enough and have too many long rest periods. The body must learn that it has to eliminate lactic acid fast, so you force high-intensity play with minimal rest during these small-sided games. This will promote a good aerobic system -- the key to fast recovery.
The fuel for the game is part fat (for low-intensity work) and part glucose or glycogen (for low- and high-intensity work). Even the leanest player has plenty of fat for a whole game, but the problem is that the body has to work at metabolizing fat and you can't run real fast if fat is your main fuel. Carbohydrates, on the other hand, provide energy very quickly -- thus you have the energy quickly to run faster.
The problem is that the carbohydrate tank is limited, and if you run out, fat becomes the fuel source and you can't run fast if fat is the only fuel. Most players start to run low on carbohydrates in the last 15 to 30 minutes of a 90-minute game. When this happens, you can't run as fast or run fast very often because you are low on fuel (carbohydrates). So, in spite of a good aerobic system, limited fuel for high-intensity work means you won't run fast. Ever wonder why so many goals are scored late in a game?
There are ways to boost energy while playing. Most players don't eat real well (too little carbohydrate at the wrong times of the day) and go into the game with a less-than-optimal tank of carbohydrates. Consuming some carbohydrate right before the game and at halftime can keep blood glucose levels up and give the muscles some fuel they wouldn't have had. You can increase your running volume and intensity late in the game this way. This has been shown in soccer, running, cycling, triathlon and other sports where low carbohydrate is a factor in fatigue.
While some players can eat candy of some sort, most people don't like the solid food in their stomach while playing. New drinks can deliver lots of carbohydrate that are rapidly absorbed by the small intestine and then delivered by the blood to the muscles in need of the fuel. The carbohydrate is formulated is such a way that it shows up in the blood within a few minutes.
Carbonated sodas are never the correct choice. Instead try products like EnduroxR4 or GatorPro, PowerAde, or others you might find in a nutritional or grocery store (ingredients should say maltodextrin, or high fructose corn syrup, or glucose polymers).
But training to recover fast, and drinking the right source of carbohydrates for that game is only one part of the recovery process. Now you have to recover from the game to play the next game. That involves repairing the damage to muscles that occurs as a result of exercise and refilling your fuel tank so you have more fuel for exercise in your tank than your opponent -- the topics of parts 2 and 3.
You will see that research has led to advances in post-exercise recovery that have been incorporated into new products that can help prepare for, and recover from, competition.
Next: Repairing muscle damage