diff --git a/src/components/WorkoutPlot.tsx b/src/components/WorkoutPlot.tsx
index de8c3b1..2e5575d 100644
--- a/src/components/WorkoutPlot.tsx
+++ b/src/components/WorkoutPlot.tsx
@@ -1,6 +1,6 @@
 import React from "react";
 import styled from "styled-components";
-import { Interval, Intensity, IntensityRange, FreeIntensity, Duration } from "make-workout";
+import { Interval, Intensity, IntensityRange, FreeIntensity, Duration, totalDuration } from "make-workout";
 
 type BarProps = {
   width: string;
@@ -37,9 +37,6 @@ const zoneColor = (intensity: Intensity | IntensityRange | FreeIntensity): strin
   return "#7f7f7f";
 }
 
-export const totalDuration = (intervals: Interval[]): Duration =>
-  intervals.reduce((total, interval) => total.add(interval.duration), new Duration(0));
-
 const toBarProps = (interval: Interval, workoutDuration: Duration): BarProps => ({
   background: zoneColor(interval.intensity),
   width: `${interval.duration.seconds / workoutDuration.seconds * 100 - 0.1}%`,