The weakest link in the chain is braking on downhill, but I don't mean the bike chain, but personal fitness. If you push yourself to the limit and think about yourself, you can notice that it is often not your driving skills that limit your speed, but rather individual parts of your body that prevent you from going faster due to a lack of strength and endurance. The core muscles as well as the chest, back and shoulder areas play a crucial role. If the upper arms are involved, especially the triceps, then it looks very good. It's only annoying when it's your fingers that can no longer hold the handlebars sufficiently and the brake levers feel like torture instruments. Then, at the latest, your fingers will slow you down, but how can I prevent that? Choosing one suitable handle with good cushioning properties and ergonomic shape protects your grip strength and prevents pressure points. In addition, targeted training of the fingers helps. And now the good news, because with one Finger trainer you can greatly increase your finger strength and forearm endurance in a short time. Long descents will quickly lose their fear and by the 5th lap in the bike park, your fingers and forearms will still feel loose. The advantage of finger training is that the training device is easy to take with you and it is sufficient to train for 1-2 minutes 2-3 times a day. You can find the corresponding exercises here LINK.
Another tip at the end: If you have mutated into a forearm monster, be careful when shaking hands, because the other person could misinterpret it as a personal attack ;-)