What's the name for those times when your attempts to get a task done right eventually get you to momentarily perform increasingly worse?

If you've tried to perfect a difficult, long task by repeating it multiple times, you'll know what I'm talking about.

You start tackling the first few phases of the problem, until you succeed. Then you fail later on and you must start over. After enough restarts, you'll eventually start having trouble performing the first few phases you thought you had down pat, way before those where you were really trying hard to get through. It's as frustrating as short-lived however: after a few more tries, you'll return to previous or higher levels of performance.

If you are the visual kind of person, here's a terribly confusing and misleading graph about what I'm talking about:

Solution 1:

You might want to look into the phenomenon of 'choking', which is believed to be a sudden regression, under stress, to an early learning phase known as 'explicit learning'. Here is an excellent article on this subject which explains the difference between explicit learning and implicit learning which is akin to what we might call 'muscle memory'.

The article explains that each type of learning uses a different part of the brain, and that even those with a high level of expertise can suddenly revert to beginner level, albeit temporarily. The example used in the article is the fascinating Wimbledon ladies' final from 1993 where Jana Novotna suffered a textbook example of 'choking' in her loss to Steffi Graf. Novotna went on to win the tournament in the same venue five years later.

Solution 2:

In software development, regression, "reappearance of a bug in a piece of software that had previously been fixed", is a commonly-used term, which in general means a regressing, a return to a previous state.

You might also refer to going stale, overtraining, or backsliding. Overtraining means:

Overtraining is a physical, behavioral, and emotional condition that occurs when the volume and intensity of an individual's exercise exceeds their recovery capacity. They cease making progress, and can even begin to lose strength and fitness.