This study examined the relationship between force and cytosolic free calcium concentration ([Ca²⁺]_c) in different fiber types from Xenopus before, during, and after cells underwent postcontractile depression (PCD). During a standardized fatigue run, force in the two fast fatiguing (FF) fiber types (types 1 and 2, n = 10) fell more quickly (5.8 vs. 8.1 min) and to a greater degree [0.36 vs. 0.51 of initial (P_o)] than in the slow fatiguing (SF) fiber type (type 3, n = 11). After the initial fatigue run, both FF and SF experienced a drop in force to <15% P_o (PCD) at a similar time (20.6 vs. 21.4 min). A second stimulation period, undertaken during PCD, produced significant recovery of force in both groups, but significantly more so in SF than FF (64 ± 7 vs. 29 ± 2% P_o). This force recovery during PCD was accompanied by a significant increase in peak [Ca²⁺]_c, particularly in SF. However, despite the significant recovery of force during stimulation while in PCD, the amount of force produced for a given peak [Ca²⁺]_c was significantly lower in both groups during PCD than at any other point in the experiment. A final stimulation period, initiated when all fibers had recovered from PCD, demonstrated a recovery of both force and peak [Ca²⁺]_c in both groups, but this recovery was significantly greater in SF vs. FF. These data demonstrate that with continuous electrical stimulation, it is possible to produce a significant recovery of force production during the normally quiescent period of PCD, but that it occurs with a decreased muscle force production for a given peak [Ca²⁺]_c. This suggests that factors other than structural alterations of the sarcoplasmic reticulum are likely the cause of PCD in these fibers.