diff --git a/rowers/dataprep.py b/rowers/dataprep.py
index 3874fa3f..9868964a 100644
--- a/rowers/dataprep.py
+++ b/rowers/dataprep.py
@@ -1448,6 +1448,8 @@ def save_workout_database(f2, r, dosmooth=True, workouttype='rower',
                 logarr = datautils.getlogarr(maxt)
                 dfgrouped = df.groupby(['workoutid'])
                 delta, cpvalues, avgpower = datautils.getcp(dfgrouped, logarr)
+                filename = 'media/cpdata_{id}.parquet.gz'.format(id=w.id)
+                df.to_parquet(filename,engine='fastparquet',compression='GZIP')
 
                 res, btvalues, res2 = utils.isbreakthrough(
                     delta, cpvalues, r.p0, r.p1, r.p2, r.p3, r.cpratio)