The Institute of Medicine has spent more than a year rigorously examining the various physical fitness tests - the sit-ups, mile-long runs and other such tasks - that schools use to test students' fitness.

They find, in a 230-page report out Thursday, that as many a middle school student may have long suspected, there's barely any evidence that most of these tests predict better health outcomes later in life. 

The committee’s review of the scientific literature revealed that studies on fitness measures for youth often were not designed to answer questions related to understanding the relationships between fitness measures and health across all ages, genders, and racial/ethnic populations.

 The committee came out especially strong against flexibility tests, things like attempting to touch one's toes while sitting -- the dreaded "sit and reach," that has vexed many inflexible eighth graders. Due to a "lack of evidence for an association between flexibility tests and health outcomes," it recommends against "including such tests" in any national guidelines for physical fitness testing.

Then, there were those sit-ups. The idea there is generally to measure muscle strength - "musculoskeletal fitness," in wonk terminology. But the committee thought these weren't measuring muscle fitness the right way.

It is apparent that many of these test items do not satisfy the physiological definitions of the three dimensions of musculoskeletal fitness. Muscle endurance fitness test items arguably may be considered the most physiologically valid field tests in youth as opposed to those measuring muscle strength and power, which are more subject to velocity control, loads, and number of repetitions.

The committee does not suggest throwing out all fitness tests, the position my eighth-grade self would have strongly endorsed. Instead, it suggests focusing on the three where there's strong evidence for a relationship to a health outcome. They are a measure of BMI, the shuttle run (to measure cardiorespiratory endurance) and a standing long jump (to measure muscle strength).