Cycling is an "easy" way to get moving. Many of the Cat5 races are folks who are just starting their journeys into health and fitness. One major issue it that cycling alone is not really that beneficial. Sure, you will lose weight and even get fast but that is about it. Best to mix in other forms of exercise and improve the old eating habits.

I saw a big boy tear up a cat4 race around here. He had an amazing amount of power and energy reserves.