Speed and power training is extremely helpful in order to gain distance. However, it is imperative that speed and power training is done correctly and appropriately. First, you must be strength training to give your body adequate support for handling "all out" effort exercises. If you don't, you are just increasing your injury risk. Also, more strength gives you more capability to have more speed/power. It doesn't mean you will automatically be faster and more powerful, but it does raise your ceiling of capability. Second, keep the reps low! High volumes of speed and power training doesn't have much benefit over low volumes. Also, as you are doing reps, once you start to fatigue you are no longer training for speed/power, rather more endurance and recruitment of muscle fibers. Third, your intent MUST be 100% on each rep. Speed and power can be gained by doing reps with max intent. That means giving everything you have into each rep. If you can check all three of these boxes then you will reap the benefits of true speed/power training.