Confidence, which dictionary.com defines as “belief in oneself and one’s powers and abilities,” is critical to athletic success. We all know this. Yet we seldom pause to reflect on the nature of confidence or to think about how best to manage it. This leads to some bad assumptions about confidence—such as the notion that more is always better—and poor confidence-management practices. The goal of this article is to give you a slightly different perspective on confidence that will help you manage your confidence better.

There are two major sources of confidence: external and internal. The main external source of confidence is experience. Like most other kinds of belief, “belief in oneself and one’s powers and abilities” requires an evidentiary foundation. Through the training process we learn what we are capable of, and in learning what we are capable of we set goals, and in pursuing these goals we look to the training process for evidence that we are moving toward them.

This component of confidence is—or should be—entirely rational. Confidence is beneficial only inasmuch as it serves to coax the best out of us, and your confidence will only coax the best out of you if your beliefs about what you are capable of are accurate. It does no more good to believe you can do more than you really can than it does to believe you can’t do as much as you really can.

This was shown in a study conducted by researchers at Michigan State University and Brock University and published in Psychology of Sport and Exercise in 2017. Seventy-five subjects answered questions designed to assess their self-efficacy (“an individual’s belief in his or her capacity to execute behaviors necessary to produce specific performance attainments”) before being asked to hold a prone plank as long as they could. Those who scored either very low or very high on the self-efficacy test failed to hold the plank as long as they expected to, whereas those in the middle matched their expectations. When the plank test was repeated, the subjects with both low and high self-efficacy scores improved, whereas those in the middle did not, indicating that only the individuals possessing realistic initial expectations for their performance had given their best effort the first time around.

It’s not at all difficult to imagine what it was that only the subjects with a realistic sense of their planking ability performed up to their potential on the first try. Those who underestimated their ability simply quit when they had done as much as they’d thought they could, while those who overestimated their ability became frustrated when they discovered planking was harder than they thought  and quit for that reason. Do you believe you can fly? Then get ready for a hard landing. As these findings indicate, contrary to popular conceptions of confidence, you cannot believe your way to optimal performance. You achieve optimal performance by being right about what you’re capable of.

That being said, there is a role for positivity in managing confidence. Now we’re talking about confidence’s internal source. All athletes have good workouts, bad workouts, and average workouts. Insofar as confidence is necessarily dependent on proof of one’s capabilities, it is possible and not uncommon for individual athletes to experience significant fluctuations in their confidence level from workout to workout. A good workout boosts confidence, a bad workout lowers confidence, and an average workout has no effect.

The most successful athletes don’t operate this way, however. Instead, their confidence level is anchored specifically to their best recent performances, and therefore it fluctuates less and is generally higher than the confidence level of athletes who give equal weight to every single workout in assessing their capabilities. Perhaps this sounds like blind optimism to you, but in fact it is not, because an athlete’s best workouts are actually the most accurate indicators of their current fitness level and performance capacity.

Think about it: No athlete can perform beyond their physical capacity in a workout. If you do something in a workout, it is because you are fit enough to do it, period. There are no miracles or flukes. Bad workouts are a different story. It is quite easy, and even unavoidable over the course of intensive training, to perform below the level of your fitness in a workout due to fatigue carried from prior training. Therefore it is simply rational to look to your better training sessions only for evidence of you current fitness level and performance capacity, and by the same token it is irrational to allow your confidence to take a hit when you have a single bad workout. And here we arrive at the title I’ve chosen for this post: If one bad workout lowers your confidence level, you weren’t confident in the first place!

To the extent that confidence is an internal psychological trait, it consists in precisely this: a resistance to letting fear, insecurity, and other irrational factors influence one’s assessment of one’s powers and abilities. The older I get and the more I experience I acquire as an athlete, a coach, and a student of endurance, the more convinced I become that good, old-fashion level-headedness is probably the single most underappreciated contributor to success in endurance sport.