Limitations

There are many ways for athletes to be limited without having an injury, or one that can be seen for that matter. This may include many things such as asthma or an iron or sodium deficiency. I, personally, have an iron and sodium deficiency that can sometimes become hard to deal with. I overheat very easily and black out. This forces me to sit down until I can see clearly. Sometimes this might cause me to actually pass out, but I have it under control. There are ways to deal with this though, including taking iron pills and including enough sodium in your diet. Limitations can be dealt with in many ways and are simply what they sound like: factors that limit what you do. These limits can be broken or tweaked.
While it may seem difficult for someone who has, per say, asthma to compete there are ways to deal with it. I know many athletes who own inhalers that they use whenever they seem a little too out of breath. They might need to take a small break to simply re-energize themselves and give their lungs a break. It is not a bad thing to have to take a break, especially at practice. I bet if you asked most athletes they would say practices are sometimes more intense than games or meets. During games or meets you get more breaks than at practice, which provides athletes with a sense of relief. At practice you are trying to build endurance so it is a good thing to be out of breath. Athletes need to push themselves at times, but just be careful to not push too far beyond your boundaries.
If you are an athlete who has something that is limiting your performance do not be ashamed or embarrassed. It is perfectly normal to be out of breath, or need to take a break, whether it is for the same reasons as others or not. Every athlete is unique and has their own knowledge of what their body can take. After all you do know your body better than anyone else. Push yourself to achieve your goals and don't let these things get in the way. Take precautions and everything will be okay. These types of limitations should not affect whether you can play or not, unless it is a serious case. With a positive outlook, everything will be okay.