From b4da24b5727d32d209aee6bf414e66470149e134 Mon Sep 17 00:00:00 2001
From: Alexander Bocken <alexander@bocken.org>
Date: Sat, 11 Apr 2026 17:40:49 +0200
Subject: [PATCH] feat: add hold timer for timed exercises with full sync
 support

- Play/Stop button replaces checkmark for duration-only exercises
- Green countdown bar with auto-completion and rest timer chaining
- Display duration in seconds (SEC) instead of minutes for holds
- ActiveWorkout model now preserves distance/duration fields on sync
- Hold timer state syncs across devices via SSE
- Workout summary shows per-set hold times for duration exercises
- Template diff compares and displays duration changes correctly
---
 package.json                                  |   2 +-
 src/lib/components/fitness/SetTable.svelte    | 128 ++++++++++++++--
 src/lib/js/workout.svelte.ts                  | 138 +++++++++++++++++-
 src/lib/js/workoutSync.svelte.ts              |  22 ++-
 src/models/ActiveWorkout.ts                   |  24 +++
 .../api/fitness/workout/active/+server.ts     |   6 +-
 .../[active=fitnessActive]/+page.svelte       |  72 ++++++---
 7 files changed, 351 insertions(+), 41 deletions(-)

diff --git a/package.json b/package.json
index 0b458dc..203100f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "homepage",
-	"version": "1.25.3",
+	"version": "1.26.0",
 	"private": true,
 	"type": "module",
 	"scripts": {
diff --git a/src/lib/components/fitness/SetTable.svelte b/src/lib/components/fitness/SetTable.svelte
index d9dd5bd..47e5493 100644
--- a/src/lib/components/fitness/SetTable.svelte
+++ b/src/lib/components/fitness/SetTable.svelte
@@ -1,5 +1,5 @@
 <script>
-	import { Check, X } from '@lucide/svelte';
+	import { Check, X, Play, Square } from '@lucide/svelte';
 	import { METRIC_LABELS } from '$lib/data/exercises';
 	import RestTimer from './RestTimer.svelte';
 	import { page } from '$app/stores';
@@ -16,8 +16,13 @@
 	 *   restAfterSet?: number,
 	 *   restSeconds?: number,
 	 *   restTotal?: number,
+	 *   holdAfterSet?: number,
+	 *   holdSeconds?: number,
+	 *   holdTotal?: number,
 	 *   onRestAdjust?: ((delta: number) => void) | null,
 	 *   onRestSkip?: (() => void) | null,
+	 *   timedHold?: boolean,
+	 *   onHoldSkip?: (() => void) | null,
 	 *   onUpdate?: ((setIndex: number, data: Record<string, number | null>) => void) | null,
 	 *   onToggleComplete?: ((setIndex: number) => void) | null,
 	 *   onRemove?: ((setIndex: number) => void) | null
@@ -31,8 +36,13 @@
 		restAfterSet = -1,
 		restSeconds = 0,
 		restTotal = 0,
+		timedHold = false,
+		holdAfterSet = -1,
+		holdSeconds = 0,
+		holdTotal = 0,
 		onRestAdjust = null,
 		onRestSkip = null,
+		onHoldSkip = null,
 		onUpdate = null,
 		onToggleComplete = null,
 		onRemove = null
@@ -52,7 +62,9 @@
 	 */
 	function handleInput(index, field, e) {
 		const target = /** @type {HTMLInputElement} */ (e.target);
-		const val = target.value === '' ? null : Number(target.value);
+		const raw = target.value === '' ? null : Number(target.value);
+		// For timedHold exercises, duration input is in seconds — convert to minutes for storage
+		const val = (timedHold && field === 'duration' && raw != null) ? raw / 60 : raw;
 		onUpdate?.(index, { [field]: val });
 	}
 
@@ -60,7 +72,10 @@
 	function formatPrev(/** @type {Record<string, any>} */ prev) {
 		const parts = [];
 		for (const m of mainMetrics) {
-			if (prev[m] != null) parts.push(`${prev[m]}`);
+			if (prev[m] != null) {
+				const v = (timedHold && m === 'duration') ? Math.round(prev[m] * 60) : prev[m];
+				parts.push(`${v}`);
+			}
 		}
 		let result = parts.join(' × ');
 		if (prev.rpe != null) result += `@${prev.rpe}`;
@@ -84,7 +99,7 @@
 				<th class="col-prev">{t('prev_header', lang)}</th>
 			{/if}
 			{#each mainMetrics as metric (metric)}
-				<th class="col-metric">{METRIC_LABELS[metric]}</th>
+				<th class="col-metric">{timedHold && metric === 'duration' ? 'SEC' : METRIC_LABELS[metric]}</th>
 			{/each}
 			{#if editable && hasRpe}
 				<th class="col-at"></th>
@@ -118,17 +133,20 @@
 					</td>
 				{/if}
 				{#each mainMetrics as metric (metric)}
+					{@const displayVal = (timedHold && metric === 'duration' && set[metric] != null)
+						? Math.round(set[metric] * 60)
+						: set[metric]}
 					<td class="col-metric" class:col-weight={metric === 'weight'}>
 						{#if editable}
 							<input
 								type="number"
-								inputmode={inputMode(metric)}
-								value={set[metric] ?? ''}
+								inputmode={timedHold && metric === 'duration' ? 'numeric' : inputMode(metric)}
+								value={displayVal ?? ''}
 								placeholder="0"
 								oninput={(e) => handleInput(i, metric, e)}
 							/>
 						{:else}
-							{set[metric] ?? '—'}
+							{displayVal ?? '—'}
 						{/if}
 					</td>
 				{/each}
@@ -148,17 +166,51 @@
 				{/if}
 				{#if editable}
 					<td class="col-check">
-						<button
-							class="check-btn"
-							class:checked={set.completed}
-							onclick={() => onToggleComplete?.(i)}
-							aria-label="Mark set complete"
-						>
-							<Check size={16} />
-						</button>
+						{#if timedHold && !set.completed}
+							{#if holdAfterSet === i}
+								<button
+									class="check-btn hold-stop"
+									onclick={() => onToggleComplete?.(i)}
+									aria-label="Stop timer"
+								>
+									<Square size={14} />
+								</button>
+							{:else}
+								<button
+									class="check-btn hold-play"
+									onclick={() => onToggleComplete?.(i)}
+									aria-label="Start hold timer"
+								>
+									<Play size={16} />
+								</button>
+							{/if}
+						{:else}
+							<button
+								class="check-btn"
+								class:checked={set.completed}
+								onclick={() => onToggleComplete?.(i)}
+								aria-label="Mark set complete"
+							>
+								<Check size={16} />
+							</button>
+						{/if}
 					</td>
 				{/if}
 			</tr>
+			{#if holdAfterSet === i && holdTotal > 0}
+				<tr class="rest-row">
+					<td colspan={totalCols} class="rest-cell">
+						<div class="hold-bar">
+							<div class="hold-fill" style:width="{holdTotal > 0 ? (holdSeconds / holdTotal) * 100 : 0}%"></div>
+							<div class="hold-controls">
+								<button class="hold-skip-btn" onclick={() => onHoldSkip?.()}>
+									{Math.floor(holdSeconds / 60)}:{(holdSeconds % 60).toString().padStart(2, '0')}
+								</button>
+							</div>
+						</div>
+					</td>
+				</tr>
+			{/if}
 			{#if restAfterSet === i && restTotal > 0}
 				<tr class="rest-row">
 					<td colspan={totalCols} class="rest-cell">
@@ -303,12 +355,58 @@
 		border-color: var(--nord14);
 		color: white;
 	}
+	.check-btn.hold-play {
+		border-color: var(--nord14);
+		color: var(--nord14);
+	}
+	.check-btn.hold-play:hover {
+		background: color-mix(in srgb, var(--nord14) 15%, transparent);
+	}
+	.check-btn.hold-stop {
+		border-color: var(--nord11);
+		color: var(--nord11);
+	}
+	.check-btn.hold-stop:hover {
+		background: color-mix(in srgb, var(--nord11) 15%, transparent);
+	}
 	.rest-row td {
 		border-top: none;
 	}
 	.rest-cell {
 		padding: 0.3rem 0.25rem;
 	}
+	.hold-bar {
+		border-radius: 8px;
+		overflow: hidden;
+		position: relative;
+		height: 2.2rem;
+		background: color-mix(in srgb, var(--nord14) 20%, var(--nord0));
+	}
+	.hold-fill {
+		position: absolute;
+		inset: 0;
+		background: var(--nord14);
+		border-radius: 8px;
+		transition: width 1s linear;
+	}
+	.hold-controls {
+		position: absolute;
+		inset: 0;
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		z-index: 1;
+	}
+	.hold-skip-btn {
+		background: none;
+		border: none;
+		font-size: 0.9rem;
+		font-weight: 700;
+		font-variant-numeric: tabular-nums;
+		color: var(--nord0);
+		cursor: pointer;
+		padding: 0.2rem 0.5rem;
+	}
 	.prev-na {
 		opacity: 0.4;
 		font-size: 0.7rem;
diff --git a/src/lib/js/workout.svelte.ts b/src/lib/js/workout.svelte.ts
index ad1d2aa..eb4366d 100644
--- a/src/lib/js/workout.svelte.ts
+++ b/src/lib/js/workout.svelte.ts
@@ -51,6 +51,10 @@ export interface StoredState {
 	restTotal: number; // total rest duration in seconds
 	restExerciseIdx: number; // which exercise the rest timer belongs to
 	restSetIdx: number; // which set the rest timer belongs to
+	holdStartedAt?: number | null; // Date.now() when hold timer started
+	holdTotal?: number; // total hold duration in seconds
+	holdExerciseIdx?: number;
+	holdSetIdx?: number;
 }
 
 export interface RemoteState {
@@ -67,6 +71,10 @@ export interface RemoteState {
 	restTotal: number;
 	restExerciseIdx: number;
 	restSetIdx: number;
+	holdStartedAt?: number | null;
+	holdTotal?: number;
+	holdExerciseIdx?: number;
+	holdSetIdx?: number;
 }
 
 function createEmptySet(): WorkoutSet {
@@ -114,6 +122,15 @@ export function createWorkout() {
 	let _restExerciseIdx = $state(-1);
 	let _restSetIdx = $state(-1);
 
+	// Hold timer (countdown for timed/duration sets)
+	let _holdSeconds = $state(0);
+	let _holdTotal = $state(0);
+	let _holdActive = $state(false);
+	let _holdStartedAt: number | null = null;
+	let _holdExerciseIdx = $state(-1);
+	let _holdSetIdx = $state(-1);
+	let _holdInterval: ReturnType<typeof setInterval> | null = null;
+
 	let _timerInterval: ReturnType<typeof setInterval> | null = null;
 	let _restInterval: ReturnType<typeof setInterval> | null = null;
 	let _onChangeCallback: (() => void) | null = null;
@@ -138,7 +155,11 @@ export function createWorkout() {
 			restStartedAt: _restActive ? _restStartedAt : null,
 			restTotal: _restTotal,
 			restExerciseIdx: _restActive ? _restExerciseIdx : -1,
-			restSetIdx: _restActive ? _restSetIdx : -1
+			restSetIdx: _restActive ? _restSetIdx : -1,
+			holdStartedAt: _holdActive ? _holdStartedAt : null,
+			holdTotal: _holdTotal,
+			holdExerciseIdx: _holdActive ? _holdExerciseIdx : -1,
+			holdSetIdx: _holdActive ? _holdSetIdx : -1
 		});
 		_onChangeCallback?.();
 	}
@@ -211,6 +232,62 @@ export function createWorkout() {
 		_restSetIdx = -1;
 	}
 
+	// --- Hold timer (timed exercise countdown) ---
+
+	function _computeHoldSeconds() {
+		if (!_holdActive || !_holdStartedAt) return;
+		const elapsed = Math.floor((Date.now() - _holdStartedAt) / 1000);
+		_holdSeconds = Math.max(0, _holdTotal - elapsed);
+		if (_holdSeconds <= 0) {
+			_onHoldComplete();
+		}
+	}
+
+	function _onHoldComplete() {
+		const exIdx = _holdExerciseIdx;
+		const setIdx = _holdSetIdx;
+		_stopHoldTimer();
+		_playRestDoneSound();
+		// Auto-complete the set
+		const ex = exercises[exIdx];
+		if (ex?.sets[setIdx] && !ex.sets[setIdx].completed) {
+			ex.sets[setIdx].completed = true;
+			// Start rest timer
+			startRestTimer(ex.restTime, exIdx, setIdx);
+		}
+		_persist();
+	}
+
+	function startHoldTimer(seconds: number, exerciseIdx: number, setIdx: number) {
+		_stopHoldTimer();
+		_holdStartedAt = Date.now();
+		_holdSeconds = seconds;
+		_holdTotal = seconds;
+		_holdActive = true;
+		_holdExerciseIdx = exerciseIdx;
+		_holdSetIdx = setIdx;
+		_holdInterval = setInterval(() => _computeHoldSeconds(), 1000);
+		_persist();
+	}
+
+	function cancelHoldTimer() {
+		_stopHoldTimer();
+		_persist();
+	}
+
+	function _stopHoldTimer() {
+		if (_holdInterval) {
+			clearInterval(_holdInterval);
+			_holdInterval = null;
+		}
+		_holdActive = false;
+		_holdSeconds = 0;
+		_holdTotal = 0;
+		_holdStartedAt = null;
+		_holdExerciseIdx = -1;
+		_holdSetIdx = -1;
+	}
+
 	// Restore from localStorage on creation
 	function restore() {
 		const stored = loadFromStorage();
@@ -254,6 +331,26 @@ export function createWorkout() {
 				_startRestInterval();
 			}
 		}
+
+		// Restore hold timer if it was active
+		if (stored.holdStartedAt && stored.holdTotal && stored.holdTotal > 0) {
+			const elapsed = Math.floor((Date.now() - stored.holdStartedAt) / 1000);
+			const remaining = stored.holdTotal - elapsed;
+			if (remaining > 0) {
+				_holdStartedAt = stored.holdStartedAt;
+				_holdTotal = stored.holdTotal;
+				_holdSeconds = remaining;
+				_holdActive = true;
+				_holdExerciseIdx = stored.holdExerciseIdx ?? -1;
+				_holdSetIdx = stored.holdSetIdx ?? -1;
+				_holdInterval = setInterval(() => _computeHoldSeconds(), 1000);
+			} else {
+				// Timer expired while away — complete it
+				_holdExerciseIdx = stored.holdExerciseIdx ?? -1;
+				_holdSetIdx = stored.holdSetIdx ?? -1;
+				_onHoldComplete();
+			}
+		}
 	}
 
 	function startFromTemplate(template: TemplateData) {
@@ -445,6 +542,7 @@ export function createWorkout() {
 	function finish() {
 		_stopTimer();
 		_stopRestTimer();
+		_stopHoldTimer();
 
 		const endTime = new Date();
 		_computeElapsed();
@@ -505,6 +603,7 @@ export function createWorkout() {
 	function cancel() {
 		_stopTimer();
 		_stopRestTimer();
+		_stopHoldTimer();
 		_reset();
 	}
 
@@ -553,6 +652,29 @@ export function createWorkout() {
 			}
 		}
 
+		// Apply hold timer state from remote
+		const holdChanged = remote.holdStartedAt !== _holdStartedAt || remote.holdTotal !== _holdTotal;
+		if (holdChanged) {
+			_stopHoldTimer();
+			if (remote.holdStartedAt && remote.holdTotal && remote.holdTotal > 0) {
+				const elapsed = Math.floor((Date.now() - remote.holdStartedAt) / 1000);
+				const remaining = remote.holdTotal - elapsed;
+				if (remaining > 0) {
+					_holdStartedAt = remote.holdStartedAt;
+					_holdTotal = remote.holdTotal;
+					_holdSeconds = remaining;
+					_holdActive = true;
+					_holdExerciseIdx = remote.holdExerciseIdx ?? -1;
+					_holdSetIdx = remote.holdSetIdx ?? -1;
+					_holdInterval = setInterval(() => _computeHoldSeconds(), 1000);
+				} else {
+					_holdExerciseIdx = remote.holdExerciseIdx ?? -1;
+					_holdSetIdx = remote.holdSetIdx ?? -1;
+					_onHoldComplete();
+				}
+			}
+		}
+
 		// Persist locally but don't trigger onChange (to avoid re-push loop)
 		saveToStorage({
 			active: true,
@@ -568,7 +690,11 @@ export function createWorkout() {
 			restStartedAt: _restActive ? _restStartedAt : null,
 			restTotal: _restTotal,
 			restExerciseIdx: _restActive ? _restExerciseIdx : -1,
-			restSetIdx: _restActive ? _restSetIdx : -1
+			restSetIdx: _restActive ? _restSetIdx : -1,
+			holdStartedAt: _holdActive ? _holdStartedAt : null,
+			holdTotal: _holdTotal,
+			holdExerciseIdx: _holdActive ? _holdExerciseIdx : -1,
+			holdSetIdx: _holdActive ? _holdSetIdx : -1
 		});
 	}
 
@@ -601,6 +727,12 @@ export function createWorkout() {
 		get restStartedAt() { return _restStartedAt; },
 		get restExerciseIdx() { return _restExerciseIdx; },
 		get restSetIdx() { return _restSetIdx; },
+		get holdTimerSeconds() { return _holdSeconds; },
+		get holdTimerTotal() { return _holdTotal; },
+		get holdTimerActive() { return _holdActive; },
+		get holdStartedAt() { return _holdStartedAt; },
+		get holdExerciseIdx() { return _holdExerciseIdx; },
+		get holdSetIdx() { return _holdSetIdx; },
 		restore,
 		startFromTemplate,
 		startEmpty,
@@ -618,6 +750,8 @@ export function createWorkout() {
 		startRestTimer,
 		cancelRestTimer,
 		adjustRestTimer,
+		startHoldTimer,
+		cancelHoldTimer,
 		finish,
 		cancel,
 		applyRemoteState,
diff --git a/src/lib/js/workoutSync.svelte.ts b/src/lib/js/workoutSync.svelte.ts
index b3e31c8..31e4a61 100644
--- a/src/lib/js/workoutSync.svelte.ts
+++ b/src/lib/js/workoutSync.svelte.ts
@@ -26,6 +26,10 @@ interface ServerWorkout {
   restTotal: number;
   restExerciseIdx: number;
   restSetIdx: number;
+  holdStartedAt: number | null;
+  holdTotal: number;
+  holdExerciseIdx: number;
+  holdSetIdx: number;
 }
 
 export function createWorkoutSync() {
@@ -56,7 +60,11 @@ export function createWorkoutSync() {
       restStartedAt: workout.restStartedAt,
       restTotal: workout.restTimerTotal,
       restExerciseIdx: workout.restExerciseIdx,
-      restSetIdx: workout.restSetIdx
+      restSetIdx: workout.restSetIdx,
+      holdStartedAt: workout.holdStartedAt,
+      holdTotal: workout.holdTimerTotal,
+      holdExerciseIdx: workout.holdExerciseIdx,
+      holdSetIdx: workout.holdSetIdx
     };
   }
 
@@ -124,7 +132,11 @@ export function createWorkoutSync() {
         restStartedAt: doc.restStartedAt ?? null,
         restTotal: doc.restTotal ?? 0,
         restExerciseIdx: doc.restExerciseIdx ?? -1,
-        restSetIdx: doc.restSetIdx ?? -1
+        restSetIdx: doc.restSetIdx ?? -1,
+        holdStartedAt: doc.holdStartedAt ?? null,
+        holdTotal: doc.holdTotal ?? 0,
+        holdExerciseIdx: doc.holdExerciseIdx ?? -1,
+        holdSetIdx: doc.holdSetIdx ?? -1
       });
 
       status = 'synced';
@@ -245,7 +257,11 @@ export function createWorkoutSync() {
             restStartedAt: serverDoc.restStartedAt ?? null,
             restTotal: serverDoc.restTotal ?? 0,
             restExerciseIdx: serverDoc.restExerciseIdx ?? -1,
-            restSetIdx: serverDoc.restSetIdx ?? -1
+            restSetIdx: serverDoc.restSetIdx ?? -1,
+            holdStartedAt: serverDoc.holdStartedAt ?? null,
+            holdTotal: serverDoc.holdTotal ?? 0,
+            holdExerciseIdx: serverDoc.holdExerciseIdx ?? -1,
+            holdSetIdx: serverDoc.holdSetIdx ?? -1
           });
         }
         connectSSE();
diff --git a/src/models/ActiveWorkout.ts b/src/models/ActiveWorkout.ts
index c20f81b..4f0f345 100644
--- a/src/models/ActiveWorkout.ts
+++ b/src/models/ActiveWorkout.ts
@@ -4,6 +4,8 @@ export interface IActiveWorkoutSet {
   reps: number | null;
   weight: number | null;
   rpe: number | null;
+  distance: number | null;
+  duration: number | null;
   completed: boolean;
 }
 
@@ -29,6 +31,10 @@ export interface IActiveWorkout {
   restTotal: number;
   restExerciseIdx: number;
   restSetIdx: number;
+  holdStartedAt: number | null;
+  holdTotal: number;
+  holdExerciseIdx: number;
+  holdSetIdx: number;
   updatedAt?: Date;
 }
 
@@ -36,6 +42,8 @@ const ActiveWorkoutSetSchema = new mongoose.Schema({
   reps: { type: Number, default: null },
   weight: { type: Number, default: null },
   rpe: { type: Number, default: null },
+  distance: { type: Number, default: null },
+  duration: { type: Number, default: null },
   completed: { type: Boolean, default: false }
 }, { _id: false });
 
@@ -109,6 +117,22 @@ const ActiveWorkoutSchema = new mongoose.Schema(
     restSetIdx: {
       type: Number,
       default: -1
+    },
+    holdStartedAt: {
+      type: Number,
+      default: null
+    },
+    holdTotal: {
+      type: Number,
+      default: 0
+    },
+    holdExerciseIdx: {
+      type: Number,
+      default: -1
+    },
+    holdSetIdx: {
+      type: Number,
+      default: -1
     }
   },
   {
diff --git a/src/routes/api/fitness/workout/active/+server.ts b/src/routes/api/fitness/workout/active/+server.ts
index c691256..0414d68 100644
--- a/src/routes/api/fitness/workout/active/+server.ts
+++ b/src/routes/api/fitness/workout/active/+server.ts
@@ -34,7 +34,7 @@ export const PUT: RequestHandler = async ({ request, locals }) => {
   try {
     await dbConnect();
     const data = await request.json();
-    const { name, mode, activityType, templateId, exercises, paused, elapsed, savedAt, expectedVersion, restStartedAt, restTotal, restExerciseIdx, restSetIdx } = data;
+    const { name, mode, activityType, templateId, exercises, paused, elapsed, savedAt, expectedVersion, restStartedAt, restTotal, restExerciseIdx, restSetIdx, holdStartedAt, holdTotal, holdExerciseIdx, holdSetIdx } = data;
 
     if (!name) {
       return json({ error: 'Name is required' }, { status: 400 });
@@ -69,6 +69,10 @@ export const PUT: RequestHandler = async ({ request, locals }) => {
           restTotal: restTotal ?? 0,
           restExerciseIdx: restExerciseIdx ?? -1,
           restSetIdx: restSetIdx ?? -1,
+          holdStartedAt: holdStartedAt ?? null,
+          holdTotal: holdTotal ?? 0,
+          holdExerciseIdx: holdExerciseIdx ?? -1,
+          holdSetIdx: holdSetIdx ?? -1,
           version: newVersion
         },
         $setOnInsert: { userId }
diff --git a/src/routes/fitness/[workout=fitnessWorkout]/[active=fitnessActive]/+page.svelte b/src/routes/fitness/[workout=fitnessWorkout]/[active=fitnessActive]/+page.svelte
index ac51a77..c7d4b8c 100644
--- a/src/routes/fitness/[workout=fitnessWorkout]/[active=fitnessActive]/+page.svelte
+++ b/src/routes/fitness/[workout=fitnessWorkout]/[active=fitnessActive]/+page.svelte
@@ -583,6 +583,7 @@
 			const exercise = getExerciseById(ex.exerciseId, lang);
 			const metrics = getExerciseMetrics(exercise);
 			const isCardio = metrics.includes('distance');
+			const isDurationOnly = metrics.includes('duration') && !metrics.includes('weight') && !metrics.includes('reps');
 			const isBilateral = exercise?.bilateral ?? false;
 			const weightMul = isBilateral ? 2 : 1;
 
@@ -599,6 +600,8 @@
 				if (isCardio) {
 					exDistance += s.distance ?? 0;
 					exDuration += s.duration ?? 0;
+				} else if (isDurationOnly) {
+					exDuration += s.duration ?? 0;
 				} else {
 					const w = (s.weight ?? 0) * weightMul;
 					const r = s.reps ?? 0;
@@ -618,6 +621,7 @@
 				exerciseId: ex.exerciseId,
 				sets,
 				isCardio,
+				isDurationOnly,
 				tonnage: exTonnage,
 				distance: exDistance,
 				duration: exDuration,
@@ -667,19 +671,21 @@
 				const metrics = getExerciseMetrics(exercise);
 				if (metrics.includes('distance')) continue; // skip cardio
 
+				const isDurOnly = metrics.includes('duration') && !metrics.includes('weight') && !metrics.includes('reps');
 				const completedSets = actual.sets.filter((/** @type {any} */ s) => s.completed);
 				if (completedSets.length === 0) continue;
 
-				// Check if sets differ in count, reps, or weight
+				// Check if sets differ
 				const tmplSets = tmplEx.sets ?? [];
 				let changed = completedSets.length !== tmplSets.length;
 				if (!changed) {
 					for (let i = 0; i < completedSets.length; i++) {
 						const a = completedSets[i];
-						const t = tmplSets[i];
-						if ((a.reps ?? 0) !== (t.reps ?? 0) || (a.weight ?? 0) !== (t.weight ?? 0)) {
-							changed = true;
-							break;
+						const tp = tmplSets[i];
+						if (isDurOnly) {
+							if ((a.duration ?? 0) !== (tp.duration ?? 0)) { changed = true; break; }
+						} else {
+							if ((a.reps ?? 0) !== (tp.reps ?? 0) || (a.weight ?? 0) !== (tp.weight ?? 0)) { changed = true; break; }
 						}
 					}
 				}
@@ -688,12 +694,12 @@
 					diffs.push({
 						exerciseId: actual.exerciseId,
 						name: exercise?.localName ?? actual.exerciseId,
+						isDurationOnly: isDurOnly,
 						oldSets: tmplSets,
-						newSets: completedSets.map((/** @type {any} */ s) => ({
-							reps: s.reps ?? undefined,
-							weight: s.weight ?? undefined,
-							rpe: s.rpe ?? undefined
-						}))
+						newSets: completedSets.map((/** @type {any} */ s) => isDurOnly
+							? { duration: s.duration ?? undefined }
+							: { reps: s.reps ?? undefined, weight: s.weight ?? undefined, rpe: s.rpe ?? undefined }
+						)
 					});
 				}
 			}
@@ -844,7 +850,9 @@
 						<span class="ex-summary-sets">{ex.sets} {ex.sets !== 1 ? t('sets', lang) : t('set', lang)}</span>
 					</div>
 					<div class="ex-summary-stats">
-						{#if ex.isCardio}
+						{#if ex.isDurationOnly}
+							<span>{ex.sets > 0 ? Math.round((ex.duration / ex.sets) * 60) : 0}s × {ex.sets}</span>
+						{:else if ex.isCardio}
 							{#if ex.distance > 0}
 								<span>{ex.distance.toFixed(1)} km</span>
 							{/if}
@@ -888,11 +896,19 @@
 									{#each diff.newSets as set, i}
 										{@const old = diff.oldSets[i]}
 										<div class="diff-set-row">
-											{#if old}
-												<span class="diff-old">{old.weight ?? '—'} kg × {old.reps ?? '—'}</span>
-												<span class="diff-arrow">→</span>
+											{#if diff.isDurationOnly}
+												{#if old}
+													<span class="diff-old">{old.duration != null ? Math.round(old.duration * 60) : '—'}s</span>
+													<span class="diff-arrow">→</span>
+												{/if}
+												<span class="diff-new">{set.duration != null ? Math.round(set.duration * 60) : '—'}s</span>
+											{:else}
+												{#if old}
+													<span class="diff-old">{old.weight ?? '—'} kg × {old.reps ?? '—'}</span>
+													<span class="diff-arrow">→</span>
+												{/if}
+												<span class="diff-new">{set.weight ?? '—'} kg × {set.reps ?? '—'}</span>
 											{/if}
-											<span class="diff-new">{set.weight ?? '—'} kg × {set.reps ?? '—'}</span>
 										</div>
 									{/each}
 									{#if diff.newSets.length > diff.oldSets.length}
@@ -1346,6 +1362,8 @@
 		{/if}
 
 		{#each workout.exercises as ex, exIdx (exIdx)}
+			{@const exMetrics = getExerciseMetrics(getExerciseById(ex.exerciseId))}
+			{@const isDurationOnly = exMetrics.includes('duration') && !exMetrics.includes('weight') && !exMetrics.includes('reps')}
 			<div class="exercise-block">
 				<div class="exercise-header">
 					<ExerciseName exerciseId={ex.exerciseId} />
@@ -1369,18 +1387,34 @@
 				<SetTable
 					sets={ex.sets}
 					previousSets={previousData[ex.exerciseId] ?? []}
-					metrics={getExerciseMetrics(getExerciseById(ex.exerciseId))}
+					metrics={exMetrics}
 					editable={true}
+					timedHold={isDurationOnly}
 					restAfterSet={workout.restTimerActive && workout.restExerciseIdx === exIdx ? workout.restSetIdx : -1}
 					restSeconds={workout.restTimerSeconds}
 					restTotal={workout.restTimerTotal}
+					holdAfterSet={workout.holdTimerActive && workout.holdExerciseIdx === exIdx ? workout.holdSetIdx : -1}
+					holdSeconds={workout.holdTimerSeconds}
+					holdTotal={workout.holdTimerTotal}
 					onRestAdjust={(delta) => workout.adjustRestTimer(delta)}
 					onRestSkip={cancelRest}
+					onHoldSkip={() => workout.cancelHoldTimer()}
 					onUpdate={(setIdx, d) => workout.updateSet(exIdx, setIdx, d)}
 					onToggleComplete={(setIdx) => {
-						workout.toggleSetComplete(exIdx, setIdx);
-						if (ex.sets[setIdx]?.completed) {
-							workout.startRestTimer(ex.restTime, exIdx, setIdx);
+						const set = ex.sets[setIdx];
+						// If hold timer is running for this set, cancel it
+						if (workout.holdTimerActive && workout.holdExerciseIdx === exIdx && workout.holdSetIdx === setIdx) {
+							workout.cancelHoldTimer();
+							return;
+						}
+						if (isDurationOnly && set?.duration && !set.completed) {
+							// Start hold countdown — completion happens automatically
+							workout.startHoldTimer(Math.round(set.duration * 60), exIdx, setIdx);
+						} else {
+							workout.toggleSetComplete(exIdx, setIdx);
+							if (ex.sets[setIdx]?.completed) {
+								workout.startRestTimer(ex.restTime, exIdx, setIdx);
+							}
 						}
 					}}
 					onRemove={(setIdx) => workout.removeSet(exIdx, setIdx)}