The first thing that is important to understand is the context for track and cross country. These are their own sports, NOT just supplemental training. Unless the energy system and timing of the event is similar, training to get better at these sports will likely have no cross over to any other sport.
Cross country is long, steady distance training. This stands in contrast to the context of almost every other team sport that focuses on high intensity, short duration effort. You can train to be aerobically fit with a high aerobic threshold and a majority of type 1 muscle fibers OR you can train to be explosive, powerful, and quick with a majority of type 2 muscle fibers. It’s not that simple, of course, but the main focus needs to be on the fact that “doing cross country” is not going to keep you in shape for tennis or make you a better tennis player. In fact, it’s likely to have the opposite effect.
With that said, if you want to make running your primary sport, then by all means, go for it! I ran track and cross country for years as a scholastic athlete and was much better for it. All I am concerned with is the transparency and understanding that these sports are not inherently beneficial when it comes to athletic development!
If you are an athlete with aspirations outside of running sports, my recommendation is to pursue track with a focus on short to mid distance running (100-800 meters). This is because there is a much higher emphasis placed on correct form and running mechanics for these athletes than there is with the long-distance runners. The more power, speed, and performance you demand from your body, the less room for error you can have.
Running is a skill. It requires strength, control, balance, coordination, and a high pain tolerance. Anyone can go out for a run, all you need is a pair of shoes and a bit of space. That’s why running is considered as a ubiquitous mark of health and fitness because it is accessible by everyone. Unfortunately, this also creates a problem. Just because you can go run, doesn’t mean you have the ability to run well. Without a focus and practice of proper technique, a solid foundation of strength, and a base of movement specific conditioning, many people run themselves straight into injury. Pun intended.
As bipedal mammals (moving on two feet instead of four) there are two different types of movement patterns available to us: walking and running. The difference is the introduction of flight phase, or time spent in the air. When we walk, we always have one foot on the ground. As you step from side to side you are just shifting your weight from one foot to the other. This is an amazing achievement for a mammal. Most animals have 4 legs and cannot stand upright for long periods of time as a result. Since we can move on two limbs, we are able to use our arms to work with tools and hold things! And you can thank your heels for this. The ability to heel strike and maintain a balance as we step walk with a long ground contact time allows us to cover long periods of distance steadily. We sacrifice a great deal of speed and running velocity by being bipedal movers, just go race a horse or dog and tell me how it goes.
But the moment we transition into a jog, no matter how slow, we introduce flight into our stride. This means we are jumping from one foot to the other. This new move requires a new movement pattern – the fore foot strike. To help you visualize this, imagine you are jumping rope, with no shoes. You’re jumping on the front of your foot, right? Now shift to jumping on your heels. Not as easy and pretty painful... Our ankles, calves, and Achilles’ heel are designed to work as shock absorbers for our strides. This allows us to land softly, absorb force, and reproduce is effectively hundreds and thousands of times in a row without injury.
