There is no question that indoor climbing is the most effective medium for learning many basic climbing techniques. The modular holds and controlled environment found in a rock gym are ideal for simulating exact situations to train for and to memorize climbing positions and movements.
The complexities of the climbing technique can be broken down into some fundamental and universal moves that can be practiced with repetition and consistency indoors.
Techniques for resting, weight transfer, body positioning, and movement are ideally suited for indoor training. There are, however, limitations to indoor climbing. The subtle nature of real rock is impossible to economically duplicate indoors, so many techniques such as crack climbing and friction climbing still require an outdoor apprenticeship.
Using the indoor walls with the intent of training for outdoor climbing can be very effective if some important differences between the two types of climbing are recognized.
One major difference between indoor and outdoor climbing is that indoor climbing terrain is generally easier to “read.” In other words, the handholds and footholds indoors are obvious and easy to see; they protrude clearly from the wall. The top of the climb is clear.
There is no mystery about where you are going and how much strength you need to conserve to get you there. Rarely while climbing indoors does one have to stop mid-route and deal with equipment or protection problems. It is easy and common to climb indoors by literally taking a deep breath at the bottom of the wall and climbing in an all-out effort to reach the top.
Outdoor climbing is quite often the opposite. Hand- and footholds are difficult to see because they blend in with the rock. Sometimes it takes patience and poise to sort out the right holds. Outdoor routes can be long and devious. The climber must carefully pace his or her strength output.
And outdoor climbing, especially multi-pitch traditional routes, requires that the climber is able to handle protection equipment and ropes with one hand, often while hanging from the other hand in the most precarious perches. All of these outdoor climbing demands mean that the climber must be in balance, relaxed, and efficient.