diff --git a/src/stravavis/cli.py b/src/stravavis/cli.py
index a964c88..76f8139 100644
--- a/src/stravavis/cli.py
+++ b/src/stravavis/cli.py
@@ -117,6 +117,8 @@ def main():
 
     print("Processing data...")
     df = process_data(filenames)
+    if df.empty:
+        sys.exit("No data to plot")
 
     activities = None
     if args.activities_path:
diff --git a/src/stravavis/process_data.py b/src/stravavis/process_data.py
index 42ab411..6e928fa 100644
--- a/src/stravavis/process_data.py
+++ b/src/stravavis/process_data.py
@@ -38,8 +38,11 @@ def process_gpx(gpxfile: str) -> pd.DataFrame | None:
 
     for activity_track in activity.tracks:
         for segment in activity_track.segments:
-            x0 = activity.tracks[0].segments[0].points[0].longitude
-            y0 = activity.tracks[0].segments[0].points[0].latitude
+            if not segment.points:
+                continue
+
+            x0 = segment.points[0].longitude
+            y0 = segment.points[0].latitude
             d0 = 0
             for point in segment.points:
                 x = point.longitude
diff --git a/tests/gpx/empty-trkseg.gpx b/tests/gpx/empty-trkseg.gpx
new file mode 100644
index 0000000..48bf947
--- /dev/null
+++ b/tests/gpx/empty-trkseg.gpx
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<gpx version="1.1" xmlns="http://www.topografix.com/GPX/1/1" creator="https://github.com/georust/gpx">
+  <trk>
+    <trkseg />
+  </trk>
+</gpx>