The most sufficient way of training is normal training with stretching. It minimizes risk of injury and overall you get most skills gained for least conditions used. However that way is too slow. Power training is risking everything, racing against time to get fast results. For me I noticed something that injuries happens more when you train and end up outside the colour zone you started with. Example you start in the green and end up in the yellow or start in the yellow and end up in the orange. When you begin in the green, sometimes its hard to fill up all the way to keep yourself finish in the green because it will be a waste to overfill. That's why I find it easier at the orange/red zone.