I pushed a for a little while and bobsledding is a tough go. Here are a couple of things. First off, there is a max weight a sled can have and this includes the pushers. The start is the most important because it is the only time you can accelerate the sled. Once you are in,you cannot make the sled go any faster. It is just minimizing errors on the way down. The theory is if you can beat someone by .1 at the start you multiply that by about 3 and get a .3 sec advantage at the bottom. In a perfect world you want to have heavy pushers,pushing a light sled. So you can push a light sled faster, than you take the advantage of your heavy pushers mass on the way down. Some teams that have light pushers have to add weight to their sleds to make them heavier, however it is obviously a slower sled to push.
Most of the male teams throughout the world have quit large pushers and most of our world class sprinters are currently on the lighter side. I was about 235lbs and was a decathlete in college. Our current pushers on the male side are quite large and most of the guys had really good weight room strength. Lolo is light, but quite strong in the weight room and she might need to bulk up several more kilos. It is much more common for heavy males to be really fast than heavy females. That is why i think you see some lighter females in bobsled. Think how fast some linebacker types are, girls with larger builds are not as compareably fast.
Bobsledding is a rough go. First off, their are a lot of politics, Lolo won't have to go through this, but it is hard to move up because you are at the mercy of the drivers. They more or less choose their pushers. The top drivers get the top equipment and those guys are tough to beat. Bobsled is an incredibly expensive sport and the technology in the top sleds is not cheap.
In a typical day of pushing you spend many many hours and only get a few runs. It's not like doing a set of hurdles and walking back to the start line. You have to spend lots of time prepping your runners(blades)Once you make a run, you then have to get the bobsled on a truck/lift and get it back up the hill. I remember spending many cold days outside and it is hard to stay warm/loose. Doing max velocity sprints in freezing cold conditions is tough, especially in Europe where sometimes there was only a tiny area to warm up.
The frustrating part about bobsled is having a good push and the your pilot screws up or you are just beat because of equipment. By the way there is a lot of cheating with the equipment, kind of like Nascar. The best part about bobsled is that you get really close to your teammates and you kind of become a family. It was a lot of fun, but there is zero money in the game and it was time to move on in life.