diff --git a/src/app/api/measurements/series/__tests__/route.test.ts b/src/app/api/measurements/series/__tests__/route.test.ts
index 421908782..982c849de 100644
--- a/src/app/api/measurements/series/__tests__/route.test.ts
+++ b/src/app/api/measurements/series/__tests__/route.test.ts
@@ -133,6 +133,21 @@ describe("GET /api/measurements/series", () => {
     const res = await GET(req("kind=weight&days=3651"));
     expect(res.status).toBe(422);
   });
+
+  it.each(["restingHeartRate", "heartRateVariability", "vo2Max"])(
+    "accepts kind=%s (v1.5.5)",
+    async (kind) => {
+      // v1.5.5 — the iOS app surfaces these as series-capable; the
+      // previous enum rejected them with 422 even though the
+      // underlying MeasurementType already carried the values.
+      vi.mocked(getSession).mockResolvedValue(SESSION_OK as never);
+      vi.mocked(prisma.measurement.findMany).mockResolvedValue([] as never);
+      const res = await GET(req(`kind=${kind}&days=30`));
+      expect(res.status).toBe(200);
+      const body = (await res.json()) as { data: { kind: string } };
+      expect(body.data.kind).toBe(kind);
+    },
+  );
 });
 
 describe("GET /api/measurements/series — 422 multi-issue (v1.4.43 W6)", () => {
diff --git a/src/app/api/measurements/series/route.ts b/src/app/api/measurements/series/route.ts
index 95e7f2fba..02536ac2b 100644
--- a/src/app/api/measurements/series/route.ts
+++ b/src/app/api/measurements/series/route.ts
@@ -34,6 +34,14 @@ const kindEnum = z.enum([
   "totalBodyWater",
   "boneMass",
   "oxygenSaturation",
+  // v1.5.5 — the iOS app surfaces these as series-capable, but
+  // the route used to reject the trend/detail view request with a
+  // 422. The underlying MeasurementType enum already carries each
+  // value; this list extends the camelCase wire shape so the route
+  // matches the data it can serve.
+  "restingHeartRate",
+  "heartRateVariability",
+  "vo2Max",
 ]);
 
 const querySchema = z.object({
@@ -58,6 +66,9 @@ const KIND_TO_TYPE: Record<z.infer<typeof kindEnum>, MeasurementType> = {
   totalBodyWater: "TOTAL_BODY_WATER",
   boneMass: "BONE_MASS",
   oxygenSaturation: "OXYGEN_SATURATION",
+  restingHeartRate: "RESTING_HEART_RATE",
+  heartRateVariability: "HEART_RATE_VARIABILITY",
+  vo2Max: "VO2_MAX",
 };
 
 interface SeriesPoint {