diff --git a/src/pages/workouts/components/LineWithLineChart.ts b/src/pages/workouts/components/LineWithLineChart.ts
index e620d79..376e89d 100644
--- a/src/pages/workouts/components/LineWithLineChart.ts
+++ b/src/pages/workouts/components/LineWithLineChart.ts
@@ -35,17 +35,21 @@ class LineWithLineController extends LineController {
     const ctx = this.chart.ctx;
     const topY = this.chart.scales.linearAxis.top;
     const bottomY = this.chart.scales.linearAxis.bottom;
-    const zoom =
-      (this.chart.chartArea.right - this.chart.chartArea.left) /
-      this.chart.config.data!.labels!.length;
     const xVertical = this.getMapX();
+    // The X axis is a time scale with irregular intervals (pauses), so the
+    // pixel position must come from Chart.js itself, not from index * zoom.
+    const meta = this.chart.getDatasetMeta(0);
     for (const i in xVertical) {
-      // console.log("xVertical", xVertical)
-      // console.log("ctx", this.chart)
+      const idx = Number(i);
+      const point = meta.data[idx] as { x?: number } | undefined;
+      const x = point?.x ?? NaN;
+      if (!Number.isFinite(x)) {
+        continue;
+      }
       ctx.save();
       ctx.beginPath();
-      ctx.moveTo(xVertical[i] * zoom, topY);
-      ctx.lineTo(xVertical[i] * zoom, bottomY);
+      ctx.moveTo(x, topY);
+      ctx.lineTo(x, bottomY);
       ctx.lineWidth = 3;
       ctx.strokeStyle = "#666";
       ctx.stroke();