Static vs. Dynamic.

The rational behind the static technique by the World Cup climbers.

When you go dynamic to the next hold you create a large amount of load, landing and grabbing the hold with your upper hand. When you instead take the next hold smooth and static, you enables for a millisecond rest plus the upper hand carefully positiones perfect directely.

The impact of the lower hand is less on a dynamic move compared to a static move where you have to lock-of. It might seem that the dynamic move is less fatigue but it is often the other way around. The dynamic move creates a lot of load on your forearm by landing meanwhile the static creates a lot of load on your biceps and shoulder muscles. The weakest link of the climber is often the forearm muscles so you should try to minimize the effort here.

In the end of a route, when you are tired, it is often impossible to climb static and lock-of meaning that you have to go dynamic. The WC climbers are often so programmed to only do static moves so you can often see them climbing static and controlled and suddenly they just fall off when the static chain is broken. The best climbers often climbs static in the beginning and then the last moves dynamic and are equally tired in the upper body, shoulders, triceps and biceps and the forearm muscles.

In bouldering, it is almost always just the forearm muscles that are finished.

Training

It is comparatively simple to perform a static move. The dynamic move is much more difficult to perform precise. Techniquewise you should put as much of your training on dynamic moves meanwhile your muscles training should be put on static moves.

However, in the beginning of your career you should focus on dynamic moves and get this technique in your backbone. Once you know this perfect you can go for muscles training. It is very difficult to do the opposite.

It should also been mentioned that once we are talking static moves we are mostly talking about knee-drop pull in moves which are so popular on competitions and also on limestone.

When the WC climbers lock-of and and grabs the next hold static, they make the upper hand rest for a milli second and there is low impact on the upper hand when grabbing the hold.