Confidence is the belief you can perform a task, it is built up from experience and exposure to situation (Magyar & Duda, 2000). As a Mental Training consultant and a coach, I think confidence is a state (that it can be modified), and that specific action can be taken, by the athlete and coach, to increase confidence.
To improve confidence, it is similar t
o motivation and comes back to the "challenge concept". To much challenge and the athletes can lose confidence, to easy of a challenge and the athlete will not gain any confidence. I need to find the challenge zone appropriate for the athlete. Also, the base confidence in a task allow the athlete to "push" his boundary more. The more confidence an athlete has, the more you can challenge them.
As a coach, I need to know the level of confidence of my athlete in specific task and situation (that is definitely the "art" of coaching!). To do so, early in the season I test my athletes in different situation to see how they react, how they ski and how they perceive they skied. Building that relation and communication help me understand what level of confidence they have. Once I have determined their "level" of confidence, I plan my training accordingly to prepare them to competition. Knowing what level of challenge they will have to face (in skiing all competitor might have to race on the same difficult hill) I progress the training environment to build that confidence. I can adjust many variable from session to session and event within a training session. For example, I can adjust the challenge to make it a bit easier at the end of the training session when the athletes are getting tired. I can also do the opposite if I know the athletes have a high confidence and I want to challenge them further.
Based on Bandura's Social-Congnitive theory (Bandura, 1977) self-efficacy (which include self-confidence) have transferability. In a 2013 article, alpine skier Erin Mielzynski said she was using mountain biking to help her gain confidence at higher speed in skiing, "It's just about pushing your limits,". Athlete can use off-season's activities to build their confidence, mental thoughtless and be prepare to take on new challenges in the new season. Erin uses mountain biking, but anything can be used. The previous two fall we use climbing and parkour to build confidence. Thing as simple as strength training in the gym can also be used to improve confidence. By reaching a higher box jump, learning a new movement or lifting a heavier weight, we can help our athletes improve their confidence.
Magyar M.T., Duda J.L. Confidence restoration following athletic injury. The Sport Psychologist, 2000, 14, 372-390