diff --git a/bin/make-workout.js b/bin/make-workout.js
index bf3d617..170a56b 100755
--- a/bin/make-workout.js
+++ b/bin/make-workout.js
@@ -1,14 +1,14 @@
 #!/usr/bin/env node
 /* eslint-disable @typescript-eslint/no-var-requires */
 const fs = require("fs");
-const { generateZwo, parse, stats, parseCliOptions } = require("../dist/index");
+const { generateZwo, parse, stats, formatStats, parseCliOptions } = require("../dist/index");
 
 const opts = parseCliOptions();
 
 const workout = parse(fs.readFileSync(opts.file, "utf8"));
 
 if (opts.stats) {
-  console.log(stats(workout));
+  console.log(formatStats(stats(workout)));
 } else {
   console.log(generateZwo(workout));
 }
diff --git a/src/index.ts b/src/index.ts
index 733a032..6ff812d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,6 @@
 export { generateZwo } from "./generateZwo";
 export { parse } from "./parser";
-export { stats } from "./stats";
+export { stats, formatStats } from "./stats";
 export { parseCliOptions } from "./parseCliOptions";
 
 // types
diff --git a/src/stats/index.ts b/src/stats/index.ts
index 773eca3..dc6a250 100644
--- a/src/stats/index.ts
+++ b/src/stats/index.ts
@@ -1,24 +1,41 @@
 import { Workout } from "../ast";
+import { Duration } from "../Duration";
+import { Intensity } from "../Intensity";
 import { averageIntensity } from "./averageIntensity";
 import { normalizedIntensity } from "./normalizedIntensity";
 import { totalDuration } from "./totalDuration";
 import { tss } from "./tss";
-import { zoneDistribution } from "./zoneDistribution";
+import { zoneDistribution, ZoneDuration } from "./zoneDistribution";
+
+export type Stats = {
+  totalDuration: Duration;
+  averageIntensity: Intensity;
+  normalizedIntensity: Intensity;
+  tss: number;
+  zones: ZoneDuration[];
+};
 
 // Generates statistics
-export const stats = ({ intervals }: Workout): string => {
+export const stats = ({ intervals }: Workout): Stats => {
   const duration = totalDuration(intervals);
-  const avgIntensity = averageIntensity(intervals);
   const normIntensity = normalizedIntensity(intervals);
-  const zones = zoneDistribution(intervals);
+  return {
+    totalDuration: totalDuration(intervals),
+    averageIntensity: averageIntensity(intervals),
+    normalizedIntensity: normalizedIntensity(intervals),
+    tss: tss(duration, normIntensity),
+    zones: zoneDistribution(intervals),
+  };
+};
 
+export const formatStats = ({ totalDuration, averageIntensity, normalizedIntensity, tss, zones }: Stats) => {
   return `
-Total duration: ${(duration.seconds / 60).toFixed()} minutes
+Total duration: ${(totalDuration.seconds / 60).toFixed()} minutes
 
-Average intensity: ${(avgIntensity.value * 100).toFixed()}%
-Normalized intensity: ${(normIntensity.value * 100).toFixed()}%
+Average intensity: ${(averageIntensity.value * 100).toFixed()}%
+Normalized intensity: ${(normalizedIntensity.value * 100).toFixed()}%
 
-TSS: ${tss(duration, normIntensity).toFixed()}
+TSS: ${tss.toFixed()}
 
 Zone Distribution:
 ${zones.map(({ name, duration }) => `${(duration.seconds / 60).toFixed().padStart(3)} min - ${name}`).join("\n")}
diff --git a/src/stats/zoneDistribution.ts b/src/stats/zoneDistribution.ts
index 53a15bd..0d4508b 100644
--- a/src/stats/zoneDistribution.ts
+++ b/src/stats/zoneDistribution.ts
@@ -5,7 +5,7 @@ import { intensityValueToZoneType, ZoneType } from "../ZoneType";
 import { intervalsToIntensityNumbers } from "./intervalsToIntensityNumbers";
 
 type NumericZoneDuration = { name: string; duration: number };
-type ZoneDuration = { name: string; duration: Duration };
+export type ZoneDuration = { name: string; duration: Duration };
 
 const emptyZones = (): Record<ZoneType, NumericZoneDuration> => ({
   Z1: { name: "Z1: Recovery", duration: 0 },
diff --git a/test/cli.test.ts b/test/cli.test.ts
index 6b3cf8a..1f84125 100644
--- a/test/cli.test.ts
+++ b/test/cli.test.ts
@@ -1,9 +1,9 @@
 import * as fs from "fs";
 import { generateZwo } from "../src/generateZwo";
 import { parse } from "../src/parser";
-import { stats } from "../src/stats";
+import { formatStats, stats } from "../src/stats";
 
-const createStats = (filename: string) => stats(parse(fs.readFileSync(filename, "utf8")));
+const createStats = (filename: string) => formatStats(stats(parse(fs.readFileSync(filename, "utf8"))));
 const createZwo = (filename: string) => generateZwo(parse(fs.readFileSync(filename, "utf8")));
 
 const filenames = [