diff --git a/targets/watch/Info.plist b/targets/watch/Info.plist
index f683276..f095216 100644
--- a/targets/watch/Info.plist
+++ b/targets/watch/Info.plist
@@ -1,5 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
-  <dict/>
+  <dict>
+    <key>NSHealthShareUsageDescription</key>
+    <string>SwimBuddy needs access to your health data to track your swim workouts.</string>
+    <key>NSHealthUpdateUsageDescription</key>
+    <string>SwimBuddy needs to save your swim workout data to Health.</string>
+  </dict>
 </plist>
\ No newline at end of file
diff --git a/targets/watch/WorkoutManager.swift b/targets/watch/WorkoutManager.swift
index 997f509..00da603 100644
--- a/targets/watch/WorkoutManager.swift
+++ b/targets/watch/WorkoutManager.swift
@@ -5,7 +5,7 @@ import WatchKit
 import WatchConnectivity
 import CoreMotion
 
-class WorkoutManager: ObservableObject {
+class WorkoutManager: NSObject, ObservableObject, HKLiveWorkoutBuilderDelegate {
     @Published var isWorkoutActive = false
     @Published var savedWorkouts: [StoredWorkout] = []
     @Published var completedWorkouts: [StoredWorkout] = []
@@ -39,9 +39,41 @@ class WorkoutManager: ObservableObject {
     private var wasStationary = false
     private var stationarySince: Date?
     @Published var lapDetected = false
+    @Published var healthKitAuthorized = false
 
-    init() {
+    override init() {
+        super.init()
         healthStore = HKHealthStore()
+        requestHealthKitAuthorization()
+    }
+
+    private func requestHealthKitAuthorization() {
+        guard let healthStore = healthStore else { return }
+        let typesToRead: Set<HKObjectType> = [
+            HKQuantityType.quantityType(forIdentifier: .heartRate)!,
+            HKQuantityType.quantityType(forIdentifier: .activeEnergyBurned)!,
+            HKObjectType.workoutType()
+        ]
+        let typesToWrite: Set<HKSampleType> = [
+            HKObjectType.workoutType()
+        ]
+
+        if healthStore.authorizationStatus(for: .workoutType()) == .sharingAuthorized {
+            DispatchQueue.main.async {
+                self.healthKitAuthorized = true
+            }
+            return
+        }
+
+        healthStore.requestAuthorization(toShare: typesToWrite, read: typesToRead) { [weak self] success, error in
+            if let error = error {
+                print("HealthKit authorization failed: \(error)")
+            }
+            DispatchQueue.main.async {
+                self?.healthKitAuthorized = success
+                print("HealthKit authorization: \(success)")
+            }
+        }
     }
 
     // MARK: - Data Persistence
@@ -106,6 +138,12 @@ class WorkoutManager: ObservableObject {
     func startWorkout() {
         guard selectedWorkout != nil else { return }
 
+        if !healthKitAuthorized {
+            print("HealthKit not authorized, requesting...")
+            requestHealthKitAuthorization()
+            return
+        }
+
         isWorkoutActive = true
         currentSetIndex = 0
         currentRep = 0
@@ -116,12 +154,14 @@ class WorkoutManager: ObservableObject {
         wasStationary = false
         stationarySince = nil
 
-        startHealthKitWorkout()
+        startHealthKitWorkout(poolLength: selectedWorkout?.poolLength ?? 25)
         startHeartRateQuery()
         startCalorieQuery()
         startTimer()
         startLapDetection()
-        WKInterfaceDevice.current().enableWaterLock()
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+            WKInterfaceDevice.current().enableWaterLock()
+        }
         WKInterfaceDevice.current().play(.start)
     }
 
@@ -418,19 +458,26 @@ class WorkoutManager: ObservableObject {
 
     // MARK: - HealthKit
 
-    private func startHealthKitWorkout() {
+    private func startHealthKitWorkout(poolLength: Double) {
         guard let healthStore = healthStore else { return }
 
         let config = HKWorkoutConfiguration()
         config.activityType = .swimming
         config.locationType = .indoor
+        config.swimmingLocationType = .pool
+        config.lapLength = HKQuantity(unit: .meter(), doubleValue: poolLength)
 
         do {
             activeWorkout = try HKWorkoutSession(healthStore: healthStore, configuration: config)
-            let workoutBuilder = HKWorkoutBuilder(healthStore: healthStore, configuration: config, device: nil)
+            let workoutBuilder = activeWorkout!.associatedWorkoutBuilder()
+            workoutBuilder.delegate = self
             self.builder = workoutBuilder
             activeWorkout?.startActivity(with: Date())
-            workoutBuilder.beginCollection(withStart: Date()) { _, _ in }
+            workoutBuilder.beginCollection(withStart: Date()) { success, error in
+                if let error = error {
+                    print("Failed to begin collection: \(error)")
+                }
+            }
         } catch {
             print("Failed to start HealthKit workout: \(error)")
         }
@@ -438,11 +485,40 @@ class WorkoutManager: ObservableObject {
 
     private func endHealthKitWorkout() {
         activeWorkout?.end()
-        builder?.endCollection(withEnd: Date()) { [weak self] _, _ in
+        builder?.endCollection(withEnd: Date()) { [weak self] success, error in
+            if let error = error {
+                print("Failed to end collection: \(error)")
+            }
             self?.builder?.finishWorkout { _, _ in }
         }
     }
 
+    // MARK: - HKLiveWorkoutBuilderDelegate
+
+    func workoutBuilder(_ workoutBuilder: HKLiveWorkoutBuilder, didCollectDataOf collectedTypes: Set<HKSampleType>) {
+        for type in collectedTypes {
+            guard let quantityType = type as? HKQuantityType else { continue }
+
+            if let statistics = workoutBuilder.statistics(for: quantityType) {
+                DispatchQueue.main.async {
+                    switch quantityType {
+                    case HKQuantityType.quantityType(forIdentifier: .heartRate):
+                        let heartRateUnit = HKUnit.count().unitDivided(by: .minute())
+                        self.heartRate = statistics.mostRecentQuantity()?.doubleValue(for: heartRateUnit) ?? 0
+                    case HKQuantityType.quantityType(forIdentifier: .activeEnergyBurned):
+                        self.activeCalories = statistics.sumQuantity()?.doubleValue(for: .kilocalorie()) ?? 0
+                    default:
+                        break
+                    }
+                }
+            }
+        }
+    }
+
+    func workoutBuilderDidCollectEvent(_ workoutBuilder: HKLiveWorkoutBuilder) {
+        // Handle collected events if needed
+    }
+
     // MARK: - Sync to Phone
 
     private func syncCompletedWorkout() {
diff --git a/targets/watch/expo-target.config.js b/targets/watch/expo-target.config.js
index b16c9e0..a939029 100644
--- a/targets/watch/expo-target.config.js
+++ b/targets/watch/expo-target.config.js
@@ -4,11 +4,13 @@ module.exports = (config) => ({
 	type: "watch",
 	icon: "../../assets/icon.png",
 	deploymentTarget: "10.0",
-	frameworks: ["SwiftUI"],
+	frameworks: ["SwiftUI", "HealthKit"],
 	entitlements: {
 		"com.apple.security.application-groups":
 			config.ios?.entitlements?.[
 				"com.apple.security.application-groups"
 			] ?? [],
+		"com.apple.developer.healthkit": true,
+		"com.apple.developer.healthkit.access": [],
 	},
 });