Femtosecond pump-probe spectroscopy is used to measure the excited state absorption dynamics in triplet excitons generated by continuous wave excitation of a conjugated polymer. Saturation of the T-1-T-n transition is observed, allowing a cross-section of 2.0 x 10(-16) cm(2) to be established. Relaxation to T-1 occurs with a 300 fs timescale, but 20% of T-n states dissociate into charges.