He's talking about the sprint bars in-game when selecting a kit. I seem to recall someone put a screenshot of this up before, but I can't find it. Basically:
2 bars = shorter sprint distance (i.e. less stamina)
3 bars = longer sprint distance (i.e. more stamina)
Essentially those kits that include body armour can't sprint for as long.
2 bars = shorter sprint distance (i.e. less stamina)
3 bars = longer sprint distance (i.e. more stamina)
Essentially those kits that include body armour can't sprint for as long.