diff --git a/lib/models/workout.dart b/lib/models/workout.dart
index 67dd828..671dfc8 100644
--- a/lib/models/workout.dart
+++ b/lib/models/workout.dart
@@ -28,7 +28,7 @@ class Workout implements DatabaseRecord {
     return {
       'motivationBefore': _motivationBefore,
       'motivationAfter': _motivationAfter,
-      'workoutDate': _workoutDate,
+      'workoutDate': _workoutDate.toIso8601String(),
     };
   }
 }