This is a universal phenomenon in sports these days. In every sport, the athletes are getting bigger, faster and stronger. The level of training that these athletes do is light years ahead of what they were doing 10 and 20 years ago. Not only is the training getting more sophisticated, it is becoming more specific to the sport. Gone are the days of "hitting the gym". Athletes are participating in very directed and specific training regiments with a variety of targeted activities. Nutrition plans are helping fuel athletes better than ever and the use of trainers and sports psychologists is par for the course. To top it all off, these athletes are getting very serious about their sports at a younger age now. These athletes are being developed at these high levels earlier than in the past and the results are bigger stronger athletes. It is part of why I personally think that the NFL still has rising numbers when it comes to concussions even though they are trying to implement ways to reduce them. There isn't more contact in the sport, the players are just hitting harder than in the past. Bigger and stronger means hitting harder.