There is a truism we know intuitively but one that we rarely rely on when we start exercising, or when we continue and develop our exercise regimens. The body is a system. It is not a collection of interworking parts and processes. Specifically, if changes occur in one area, the entire body will be affected. Exercising to build muscle, for example, usually has a positive impact on bone density. The body just knows to do this because it is a system, not a collection of parts.
I have never found that building muscle made my athletic life better. I grew bigger but with the added weight or density I was slower. I have the muscle I need because I work out aerobically and my body system adjusts the muscle density to accommodate the activities that I am pursuing. Do not get me wrong. Muscle building has its place for certain activities, such as football, or other high-contact sports. It also has many positive consequences when you get older. But it has a limit. Ask any body builder what happens to their bodies if they start to back off weight lifting. Every one of them will tell you that they gain body fat like crazy. The body is a system and without the consistent calorie-burning of weight lifting, it adjusts itself to the added muscle tissue.
If you want to have a better surfer, or snow skier, or horseback rider, or something like this, then building your cardiovascular system will do you much more good than lifting weights. If you condition your body to operate at a high level of activity, then surfing, snow skiing, horseback riding, etc. will be much, much easier. You have allowed your body system to adjust and adapt.
If you want to know what kind of exercises to do in order to be a better skier, surfer, etc., look at the training methods of the professionals in that sport. Most of them incorporated a weight lifting regimen but in a limited fashion. They do aerobic exercise to refine their lung capacity, drive up their metabolism, and accustom their bodies to high-impact activity.
The body is a system and if you train it like a system you will find the best results. If you lift weights, then expect to drop some weight. Just do not focus too much on this aspect of exercise. If you run long distances, you can expect, over time, your legs to get stronger, your bones to get stronger, and most especially, your lung and metabolic ability to improve drastically.
While I was in the military, we never lived weights. That is, we never went to a gym and 'pumped iron.' We had the muscle tissue we needed because during a normal day we were lifting things, and pushing things, and otherwise using the muscles of our bodies in the way that we needed to use them. We exercised and focused on cardio, and raising the metabolism, and 'jacking up' our aerobic capacities.
So, do not be fooled by crazy exercise equipment. Do not be convinced that going to the gym and lifting weights will definitely make you a better surfer, or snow skier. It will not. You probably will not lose the weight you want to lose, either. You have to treat your body like a system in order for it to operate like a system, which is the only way it knows.