The cells are 1000mah, but to equal the performance of 4-cell nimh pack 4-LifePO4 cells would be wired in a 2S2P configuration. Making them 2000Mah at 6.4V. Since LiFePO4 cells perform better under load than NiMH cells, the 2000mah Capacity equals a the performance to a 3300mah battery in heavy use.
Since these cells have a fairly flat discharge up to 2.5 volts then dump sharply a users can still have punch to the very end of the race.
To give you an idea of how much power 2000mah is, that would be a constant 15amp load for 8min. Sounds like more than enough capacity for practice heats or even 5min races.