In training what is better fast or slow movement..? Largely it is relative to your purpose and outcome, therefore neither is better, only dependent on what you want to achieve. For most goals however you can achieve the same result with either tempo.
For example for weight loss, training at a slower pace can be a great way to achieve your goals and build your fitness at a rate that is safer. Training at a slower pace is also better for building and maintaining correct movement patterns. It can also be more meditative and help you to focus.
So what are the benefits of a faster speed training?
Depending on your goals, faster speeds can help to exert excess energy or stress and boost cardio levels, it can also help to boost your reaction time.
However the two can and do crossover you can get benefits from both types of training and both will help you improve fitness and lose weight/maintain a healthy weight.
Most importantly is to always listen to your body and be in touch with the needs of your own body and mind, and as always of course, enjoy your training 🙂🙏💫