back to Step 1) Every minute or so, the level changes. This is signaled, usually, by a double beep or, possibly, a voice cue. The required speed at the new speed level will be 0.5 km/h faster. Notes: The distance between the "start" and "turn around" markers is usually 20m; however, the test can also be carried out using a 15m track. Shuttle completion times are modified in proportion. Leger specified a 1-minute protocol: that is, each level was meant to last approximately 1 minute. However, because speed changes mid-shuttle confuse matters, the algorithm for a change in level is as follows: "the next level commences on completion of the current shuttle when the absolute difference between the time spent at the level and 60 seconds is the least". Scoring A runner who fails to reach the relevant marker in time is cautioned; if they want to continue, they must touch the marker before turning back. Two consecutive failures terminates their attempt. Their most recent successfully completed shuttle is marked as their score. Scoring is usually done using "Level.Shuttle" terminology; for example, 10.2, which means "completed 2 shuttles at level 10". Estimating VO2 max VO2 max, or milliliters of oxygen per kilogram of body mass per minute (e.g., mL/(kg·min)), is considered an excellent proxy for aerobic fitness. Attempts have been made to correlate MSFT scores with VO2 max. Do note that such estimations are fraught with difficulty as test scores, while substantially dependent on VO2 max, also depend on running efficiency, test familiarity, anaerobic capacity, personal drive, ambient temperature, running equipment (floor, shoes) and other factors. A paper by Flouris, et al. (2005) determined the following: An earlier paper by Ramsbottom, et al. (1988) suggested the following: Variations Luc Léger, the originator of the multi-stage fitness test, never did patent it. Consequently, organizations around the world have been able to incorporate subtle variations into the test. The most common variations are: First level at 8.0 km/h The Léger test requires the first level to be run at 8.5 km/h. Some organizations require it to be run at 8.0 km/h. Note that the second level is always run at 9.0 km/h. Also, speeds at subsequent levels always increment by 0.5 km/h. The impact of this variation is insignificant as almost all runners' scores easily exceed level 1. Time spent at each level All versions of the test evaluate for a change