Yeah, that's the point, it forces you to slow down and take in more information on the subject you are drawing. Most people call bullshit on the exercise, but most of the time they are not really, REALLY looking at what they are drawing, but basically glancing at it from one generalized point to the next generalized point, rather than using your eyes to follow the actual visual imaginary lines of the object and drawing them as such.
Don't go too fast or too slow, if you are getting done really fast, try those exercises, starting from the least amount of time to the longest.
>10 sec., 30 sec, 1 min., 3 min., 5 min., 10 min., exercises with basic objects
Challenge yourself to expand, draw a boot, or shoe is a good one, getting all those intricate details and textures without lifting your pencil or looking at your page, try at least drawing 3 each of the times exercises from your shoulder pivot too.