future_infantry: The three most important things about being in the infantry are
1. fitness
2. fitness
and
3. fitness
You don‘t need super high scores on the aptitude test, you don‘t need colour vision, or even 20/20 vision, you don‘t need Canadian citizenship, a high school diploma or a university degree. BUT, the infantry is a very very very physically demanding job. I would venture to say that it‘s almost entirely physical, but that wouldn‘t be true. It is also very mentally stressing, especially when you get into leadership positions, but the physicality is the primary aspect.
The better shape you‘re in, the easier it will be on you. In particular, upper body strength and cardio fitness. Infantry types love running, pushups, chinups, and heavy lifting. Learn to like running, a lot (or at least to tolerate it), and try to get your body fat down farely low, keeping within healthy norms. Go on long runs, long walks with weight on your back, lots of time in the gym on upper body weights, and just get fit.