diff --git a/public/css/editorPiscina.css b/public/css/editorPiscina.css
index 7830f3c..827c7a0 100644
--- a/public/css/editorPiscina.css
+++ b/public/css/editorPiscina.css
@@ -1,262 +1,168 @@
-/* ------------------- ESTILO GLOBAL ------------------- */
+/* === Variables === */
 :root {
   --color-primary: #0d6efd;
-  --color-success: #198754;
+  --color-secondary: #6c757d;
+  --color-light: #f9fafb;
+  --color-border: #dee2e6;
   --radius-lg: 0.75rem;
   --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
-  --transition-fast: all 0.25s ease;
   --font-family: 'Inter', sans-serif;
 }
 
-html {
-  overflow-y: scroll;
-  scroll-behavior: smooth;
-}
-
+/* === Reset === */
 body {
   font-family: var(--font-family);
-  font-size: clamp(1rem, 1vw + 0.2rem, 1.1rem);
-  line-height: 1.7;
-  background-color: #f9fafb;
+  font-size: 1rem;
+  background-color: var(--color-light);
   color: #212529;
-  margin: 0;
-  padding: 0;
 }
 
-/* ------------------- NAVBAR ------------------- */
+/* === Navbar === */
 .navbar {
   min-height: 72px;
-  padding-top: 1rem !important;
-  padding-bottom: 1rem !important;
 }
-
 .navbar .nav-link {
   font-weight: 500;
-  font-size: 1rem;
-  transition: all 0.2s ease;
 }
 
-.navbar .nav-link:hover {
-  opacity: 0.85;
-}
-
-.navbar * {
-  box-sizing: border-box;
-}
-
-/* ------------------- TARJETAS ------------------- */
+/* === Cards === */
 .card {
   border: none;
   border-radius: var(--radius-lg);
   box-shadow: var(--shadow-md);
-  background-color: white;
-  overflow: visible;
 }
 
-/* ------------------- FORMULARIOS ------------------- */
+/* === Forms === */
 .form-control,
 .form-select {
   border-radius: var(--radius-lg);
-  border: 1px solid #ced4da;
-  transition: var(--transition-fast);
-  font-size: 1rem;
+  border: 1px solid var(--color-border);
+  transition: border-color 0.2s;
 }
-
 .form-control:focus,
 .form-select:focus {
   border-color: var(--color-primary);
   box-shadow: 0 0 0 0.2rem rgba(13, 110, 253, 0.15);
 }
 
-/* ------------------- BOTONES ------------------- */
+/* === Botones === */
 button,
 .btn {
   border-radius: var(--radius-lg);
-  padding: 0.6rem 1.2rem;
   font-weight: 600;
-  font-size: 1rem;
-  transition: var(--transition-fast);
-  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
 }
-
-.btn-primary,
-.btn-success,
-.btn-outline-primary,
-.btn-outline-secondary {
-  border-width: 2px;
-}
-
 .btn-primary {
   background-color: var(--color-primary);
   border-color: var(--color-primary);
-  color: #fff;
 }
 .btn-primary:hover {
   background-color: #084298;
-  border-color: #084298;
-}
-
-.btn-success {
-  background-color: var(--color-success);
-  border-color: var(--color-success);
-  color: white;
-}
-.btn-success:hover {
-  background-color: #145c32;
-  border-color: #145c32;
-}
-
-.btn-outline-primary {
-  color: var(--color-primary);
-  border-color: var(--color-primary);
-  background-color: white;
 }
+.btn-outline-secondary:hover,
 .btn-outline-primary:hover {
-  background-color: var(--color-primary);
-  color: white;
+  opacity: 0.9;
 }
 
-.btn-outline-secondary {
-  color: #6c757d;
-  border-color: #6c757d;
-  background-color: white;
-}
-.btn-outline-secondary:hover {
-  background-color: #6c757d;
-  color: white;
-}
-
-button:disabled,
-.btn:disabled {
-  opacity: 0.65;
-  cursor: not-allowed;
-}
-
-/* ------------------- PISCINA ------------------- */
+/* === Piscina === */
 #piscinaContainer {
   background-color: #e6f7ff;
   border: 2px dashed #007bff;
-  padding: 1rem;
   border-radius: var(--radius-lg);
-  width: fit-content;
-  height: fit-content;
-  min-width: 300px;
-  min-height: 200px;
+  aspect-ratio: 2 / 1;
+  width: 100%;
+  height: auto;
   max-width: 100%;
-  box-sizing: border-box;
+  overflow: hidden;
 }
 
 #piscina {
-  display: block;
-  width: 100% !important;
-  height: 100% !important;
+  width: 100%;
+  height: 100%;
   background-image:
     linear-gradient(to right, rgba(0,0,0,0.05) 1px, transparent 1px),
     linear-gradient(to bottom, rgba(0,0,0,0.05) 1px, transparent 1px);
   background-size: 45px 45px;
-  background-position: top left;
-  overflow: hidden;
+  display: block;
 }
 
-/* ------------------- TIMELINE ------------------- */
+/* === Timeline === */
 .timeline-placeholder {
-  display: flex;
-  overflow-x: auto;
-  gap: 10px;
-  padding: 1rem;
-  border: 1px solid #ddd;
-  background: #ffffff;
+  border: 1px solid #ccc;
   border-radius: var(--radius-lg);
-  box-shadow: 0 1px 4px rgba(0,0,0,0.05);
+  padding: 1rem;
+  background-color: white;
+  box-shadow: var(--shadow-md);
+  overflow-x: auto;
 }
-
 .timeline-placeholder .step {
   min-width: 100px;
   padding: 0.5rem;
-  border: 1px solid #ccc;
   background: white;
-  border-radius: 8px;
-  text-align: center;
-  cursor: pointer;
+  border: 1px solid #ccc;
+  border-radius: 0.5rem;
   font-size: 0.85rem;
+  cursor: pointer;
   transition: all 0.2s ease;
-  box-shadow: 1px 1px 3px rgba(0,0,0,0.05);
 }
 .timeline-placeholder .step:hover {
   background-color: #dbeafe;
-  font-weight: bold;
-  transform: scale(1.03);
 }
 .step.active {
-  background-color: #0d6efd !important;
-  color: white !important;
+  background-color: var(--color-primary);
+  color: white;
   font-weight: bold;
 }
 
-/* ------------------- AUTOCOMPLETADO ------------------- */
+/* === Sugerencias figura === */
 #sugerenciasFigura {
-  margin-top: 4px;
-  padding: 6px 0;
-  background-color: #fff;
+  background: #fff;
   border: 1px solid #ccc;
   border-radius: 6px;
-  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
-  max-height: 160px;
-  overflow-y: auto;
   position: absolute;
   width: 100%;
   z-index: 10;
+  max-height: 160px;
+  overflow-y: auto;
 }
 #sugerenciasFigura button {
-  display: block;
   width: 100%;
   padding: 6px 12px;
-  font-size: 0.9rem;
   border: none;
   background: none;
   text-align: left;
-  color: #333;
+  font-size: 0.9rem;
   cursor: pointer;
-  transition: background 0.2s ease;
 }
 #sugerenciasFigura button:hover {
   background-color: #edf6ff;
-  color: #007bff;
   font-weight: 500;
 }
 
-/* ------------------- VISTA PREVIA FIGURA ------------------- */
-#previewFigura img {
-  margin-top: 8px;
-  max-width: 100%;
-  border: 1px solid #ddd;
-  border-radius: 6px;
-  height: auto;
-}
-#previewFigura p {
-  font-size: 0.85rem;
-  color: #555;
-  margin-top: 4px;
-}
-
-/* ------------------- MULTIMEDIA ------------------- */
+/* === Audio === */
 #waveform {
-  width: 100%;
-  height: 100px;
-  margin-bottom: 10px;
+  height: 80px;
+  background: #f1f3f5;
+  border-radius: 6px;
 }
 #audioPlayer {
   display: none;
 }
 
-/* ------------------- RESPONSIVO ------------------- */
+/* === Responsivo === */
 @media (max-width: 768px) {
-  #piscina {
-    min-height: 280px;
-  }
-
   .timeline-placeholder .step {
     min-width: 80px;
-    font-size: 0.75rem;
+  }
+  #piscinaContainer {
+    aspect-ratio: 1.5 / 1;
   }
 }
+
+/* === Ancho de página controlado === */
+main.container-xl {
+  max-width: 1440px;
+  margin-left: auto;
+  margin-right: auto;
+  padding-left: 2rem;
+  padding-right: 2rem;
+}
diff --git a/public/js/piscina.js b/public/js/piscina.js
index c8309a3..34e1e9d 100644
--- a/public/js/piscina.js
+++ b/public/js/piscina.js
@@ -40,6 +40,8 @@ atletas.forEach(a => {
 
 select.addEventListener('change', () => {
   const datos = JSON.parse(select.value || '{}');
+  select.dataset.id = datos.id; // << GUARDAS el ObjectId real
+
   if (datos.idPers) {
     document.getElementById('idPersonalizado').value = datos.idPers;
     document.getElementById('idPersonalizado').disabled = true;
@@ -48,6 +50,7 @@ select.addEventListener('change', () => {
     document.getElementById('idPersonalizado').disabled = false;
   }
 });
+
   let figurasFINA = [];
   try {
     const res = await fetch('/catalog/figurasFINA.json');
@@ -192,7 +195,7 @@ tipoPiscinaSelect.addEventListener('change', async () => {
       return;
     }
 
-    const idAtleta = select.value;
+    const idAtleta = select.dataset.id;
     const rol = document.getElementById('rolAtleta').value.trim().toLowerCase();
     const idPersonalizado = document.getElementById('idPersonalizado').value.trim();
     const figura = inputFigura?.value.trim();
@@ -235,114 +238,122 @@ tipoPiscinaSelect.addEventListener('change', async () => {
 
 
   function dibujarAtleta(atleta) {
-    const color = atleta.rol === 'volador' ? 'purple' : atleta.rol === 'pilar' ? 'blue' : 'red';
+  const color = atleta.rol === 'volador' ? 'purple' : atleta.rol === 'pilar' ? 'blue' : 'red';
+  const metros = convertirAMetros(atleta.x, atleta.y);
 
-    const metros = convertirAMetros(atleta.x, atleta.y);
+  const circle = new Konva.Circle({
+    x: atleta.x,
+    y: atleta.y,
+    radius: 15,
+    fill: color,
+    stroke: 'white',
+    strokeWidth: 2,
+    draggable: !modoDireccion
+  });
 
-    const circle = new Konva.Circle({
-      x: atleta.x,
-      y: atleta.y,
-      radius: 15,
-      fill: color,
-      stroke: 'white',
-      strokeWidth: 2,
-      draggable: !modoDireccion
-    });
+  const text = new Konva.Text({
+    x: atleta.x,
+    y: atleta.y,
+    text: atleta.idPersonalizado,
+    fontSize: 12,
+    fill: 'white',
+    fontStyle: 'bold',
+    align: 'center'
+  });
+  text.offsetX(text.width() / 2);
+  text.offsetY(text.height() / 2);
 
-    const text = new Konva.Text({
-      x: atleta.x,
-      y: atleta.y,
-      text: atleta.idPersonalizado,
-      fontSize: 12,
-      fill: 'white',
-      fontStyle: 'bold',
-      align: 'center'
-    });
-    text.offsetX(text.width() / 2);
-    text.offsetY(text.height() / 2);
+  const figuraText = new Konva.Text({
+    x: atleta.x - 25,
+    y: atleta.y + 18,
+    text: atleta.figura || '',
+    fontSize: 10,
+    fill: '#333',
+    fontStyle: 'italic'
+  });
+  figuraText.listening(false);
 
+  const coordText = new Konva.Text({
+    x: atleta.x - 35,
+    y: atleta.y + 30,
+    text: `${metros.metrosX}m, ${metros.metrosY}m`,
+    fontSize: 9,
+    fill: '#666'
+  });
+  coordText.listening(false);
 
-    const figuraText = new Konva.Text({
-      x: atleta.x - 25,
-      y: atleta.y + 18,
-      text: atleta.figura || '',
-      fontSize: 10,
-      fill: '#333',
-      fontStyle: 'italic'
-    });
-    figuraText.listening(false);
-
-    const coordText = new Konva.Text({
-      x: atleta.x - 35,
-      y: atleta.y + 30,
-      text: `${metros.metrosX}m, ${metros.metrosY}m`,
-      fontSize: 9,
-      fill: '#666'
-    });
-    coordText.listening(false);
-
-    circle.on('dblclick', () => {
-      const i = formacionActual.findIndex(a => a.idPersonalizado === atleta.idPersonalizado);
-      const html = `
-        <div class="p-2" style="min-width:200px;">
-          <h6 class="mb-1">${atleta.figura || 'Sin figura'}</h6>
-          <button class="btn btn-sm btn-outline-primary w-100 mb-2" onclick="activarModoDireccion(${i})">➤ Añadir Dirección</button>
-          <button class="btn btn-sm btn-outline-secondary w-100" onclick="alert('Función editar aún no implementada')">✏ Editar/Eliminar</button>
-        </div>
-      `;
-      showPopover(circle.x(), circle.y(), html);
-    });
-
-    circle.on('dragend', () => {
-      const newX = circle.x();
-      const newY = circle.y();
-      const i = formacionActual.findIndex(a => a.idPersonalizado === atleta.idPersonalizado);
-      if (i !== -1) {
-        formacionActual[i].x = newX;
-        formacionActual[i].y = newY;
-      }
-
-      const nuevosMetros = convertirAMetros(newX, newY);
-      coordText.text(`${nuevosMetros.metrosX}m, ${nuevosMetros.metrosY}m`);
-      coordText.x(newX - 35);
-      coordText.y(newY + 30);
-
-      text.x(newX - 10);
-      text.y(newY - 7);
-
-      figuraText.x(newX - 25);
-      figuraText.y(newY + 18);
-
-      layer.batchDraw();
-    });
-
-    layer.add(circle);
-    atletasKonva[atleta.idPersonalizado] = {
-      circle,
-      text,
-      figuraText,
-      coordText
-    };
-    layer.add(text);
-    layer.add(figuraText);
-    layer.add(coordText);
-
-    if (atleta.direccion) {
-    const linea = new Konva.Arrow({
-      points: [start.x, start.y, start.x, start.y],
+  let flecha = null;
+  if (atleta.direccion) {
+    flecha = new Konva.Arrow({
+      points: [atleta.direccion.x1, atleta.direccion.y1, atleta.direccion.x2, atleta.direccion.y2],
       stroke: 'black',
       fill: 'black',
       strokeWidth: 2,
       pointerLength: 10,
       pointerWidth: 10,
       dash: [4, 4]
+    });
+    layer.add(flecha);
+  }
+
+  circle.on('dblclick', () => {
+    const i = formacionActual.findIndex(a => a.idPersonalizado === atleta.idPersonalizado);
+    const html = `
+      <div class="p-2" style="min-width:200px;">
+        <h6 class="mb-1">${atleta.figura || 'Sin figura'}</h6>
+        <button class="btn btn-sm btn-outline-primary w-100 mb-2" onclick="activarModoDireccion(${i})">➤ Añadir Dirección</button>
+        <button class="btn btn-sm btn-outline-secondary w-100" onclick="alert('Función editar aún no implementada')">✏ Editar/Eliminar</button>
+      </div>
+    `;
+    showPopover(circle.x(), circle.y(), html);
   });
 
-      layer.add(dir);
+  circle.on('dragend', () => {
+    const newX = circle.x();
+    const newY = circle.y();
+    const i = formacionActual.findIndex(a => a.idPersonalizado === atleta.idPersonalizado);
+    if (i !== -1) {
+      formacionActual[i].x = newX;
+      formacionActual[i].y = newY;
     }
 
-    layer.draw();
-  }
+    const nuevosMetros = convertirAMetros(newX, newY);
+    coordText.text(`${nuevosMetros.metrosX}m, ${nuevosMetros.metrosY}m`);
+    coordText.x(newX - 35);
+    coordText.y(newY + 30);
+
+    text.x(newX - 10);
+    text.y(newY - 7);
+
+    figuraText.x(newX - 25);
+    figuraText.y(newY + 18);
+
+    if (flecha) {
+      // Actualiza flecha si existe
+      const dx = atleta.direccion.x2 - atleta.direccion.x1;
+      const dy = atleta.direccion.y2 - atleta.direccion.y1;
+      flecha.points([newX, newY, newX + dx, newY + dy]);
+    }
+
+    layer.batchDraw();
+  });
+
+  layer.add(circle);
+  layer.add(text);
+  layer.add(figuraText);
+  layer.add(coordText);
+
+  atletasKonva[atleta.idPersonalizado] = {
+    circle,
+    text,
+    figuraText,
+    coordText,
+    flecha
+  };
+
+  layer.draw();
+}
+
 
 
   window.activarModoDireccion = function(index) {
@@ -418,55 +429,22 @@ const linea = new Konva.Arrow({
     }, 100);
   }
 
-  function animarTransicion(nuevaFormacion) {
-    nuevaFormacion.forEach(a => {
-      const obj = atletasKonva[a.idPersonalizado];
-      if (obj) {
-        const { circle, text, figuraText, coordText } = obj;
+function animarTransicion(nuevaFormacion) {
+  // Limpiar capa y diccionario de atletas previos
+  layer.destroyChildren();
+  atletasKonva = {};
 
-        // Animar círculo
-        new Konva.Tween({
-          node: circle,
-          duration: 1.0,
-          x: a.x,
-          y: a.y,
-          easing: Konva.Easings.EaseInOut,
-        }).play();
+  // Redibujar cuadrícula
+  dibujarCuadricula(layer, piscinaWidth, piscinaHeight);
 
-        // Mover textos en paralelo
-        new Konva.Tween({
-          node: text,
-          duration: 1.0,
-          x: a.x - 10,
-          y: a.y - 7,
-          easing: Konva.Easings.EaseInOut,
-        }).play();
+  // Dibujar cada atleta
+  nuevaFormacion.forEach(a => {
+    dibujarAtleta(a);
+  });
 
-        new Konva.Tween({
-          node: figuraText,
-          duration: 1.0,
-          x: a.x - 25,
-          y: a.y + 18,
-          easing: Konva.Easings.EaseInOut,
-        }).play();
+  layer.draw();
+}
 
-        new Konva.Tween({
-          node: coordText,
-          duration: 1.0,
-          x: a.x - 35,
-          y: a.y + 30,
-          easing: Konva.Easings.EaseInOut,
-          onUpdate: () => {
-            const metros = convertirAMetros(a.x, a.y);
-            coordText.text(`${metros.metrosX}m, ${metros.metrosY}m`);
-          }
-        }).play();
-
-      } else {
-        dibujarAtleta(a);
-      }
-    });
-  }
 
 
   btnGuardarFormacion.addEventListener('click', async () => {
@@ -484,7 +462,7 @@ const linea = new Konva.Arrow({
       notasTacticas: notas,
       duracion: duracion || 0,
       atletas: formacionActual.map(a => ({
-        atletaId: a.atletaId._id || a.atletaId,
+        atletaId: a.atletaId,
         idPersonalizado: a.idPersonalizado,
         x: a.x,
         y: a.y,
diff --git a/public/piscina.html b/public/piscina.html
index 8d7f051..9a39aa3 100644
--- a/public/piscina.html
+++ b/public/piscina.html
@@ -12,7 +12,6 @@
   <script src="https://cdn.jsdelivr.net/npm/sweetalert2@11"></script>
 </head>
 <body>
-  <!-- NAV -->
   <nav class="navbar navbar-expand-lg navbar-dark bg-primary sticky-top shadow-sm px-4 py-3">
     <div class="container-fluid">
       <a class="navbar-brand fw-bold text-white" href="#">SwimmingArt</a>
@@ -24,7 +23,6 @@
     </div>
   </nav>
 
-  <!-- MAIN -->
   <main class="container-xl px-4 my-4">
     <section class="mb-4">
       <h2 id="tituloRutina" class="fw-bold fs-2 mb-2">Editor de Formación</h2>
@@ -34,10 +32,9 @@
       </div>
     </section>
 
-    <div class="row gx-4 gy-4 align-items-start">
-      <!-- Formulario Atleta -->
-      <div class="col-lg-5 col-xl-4">
-        <div class="card p-4 h-100">
+    <div class="row gx-4 gy-4">
+      <div class="col-lg-4">
+        <div class="card p-4 h-100 d-flex flex-column">
           <h5 class="fw-semibold mb-3 text-primary">Agregar Atleta</h5>
 
           <div class="mb-3">
@@ -58,7 +55,6 @@
           <div class="mb-3">
             <label for="idPersonalizado" class="form-label">ID personalizado</label>
             <input type="text" id="idPersonalizado" class="form-control" placeholder="Ej: A, 1, V2" readonly>
-
           </div>
 
           <div class="mb-3">
@@ -82,13 +78,12 @@
             <input type="text" id="codigoElemento" class="form-control" placeholder="Ej: TRE 1A, H4...">
           </div>
 
-          <button id="btnAgregarAtleta" class="btn btn-primary w-100">Añadir Atleta</button>
+          <button id="btnAgregarAtleta" class="btn btn-primary mt-auto">Añadir Atleta</button>
         </div>
       </div>
 
-      <!-- Piscina y Línea de Tiempo -->
-      <div class="col-lg-7 col-xl-8">
-        <div class="card p-4 h-100">
+      <div class="col-lg-8 d-flex flex-column gap-3">
+        <div class="card p-4">
           <h5 class="fw-semibold mb-3 text-primary">Piscina</h5>
 
           <div class="mb-3">
@@ -100,21 +95,26 @@
             </select>
           </div>
 
-          <div id="piscinaContainer" class="border rounded p-2 mb-4" style="width: 100%; max-width: 100%; height: auto;">
+          <div id="piscinaContainer" class="border rounded p-2 mb-4" style="width: 100%; height: auto;">
             <div id="piscina"></div>
           </div>
 
-          <div class="mb-4">
-            <button id="btnEditarFormacion" class="btn btn-outline-secondary btn-sm" disabled>Editar formación</button>
+          <div class="d-flex align-items-center justify-content-between flex-wrap gap-2 mb-3">
+            <button id="btnEditarFormacion" class="btn btn-outline-secondary btn-sm">Editar formación</button>
+            <div class="flex-grow-1">
+              <div id="waveform" style="height: 80px;"></div>
+              <div class="text-end">
+                <button id="playPauseBtn" class="btn btn-outline-primary btn-sm">Reproducir</button>
+              </div>
+            </div>
           </div>
 
-          <label class="form-label fw-semibold">Línea de Tiempo</label>
+          <label class="form-label fw-semibold mt-3">Línea de Tiempo</label>
           <div id="lineaTiempo" class="timeline-placeholder d-flex flex-wrap gap-2"></div>
         </div>
       </div>
     </div>
 
-    <!-- Datos de Formación -->
     <div class="card p-4 mt-4">
       <h5 class="fw-semibold mb-3 text-primary">Datos de Formación</h5>
       <div class="row gy-3">
@@ -138,15 +138,6 @@
         <button id="btnGuardarFormacion" class="btn btn-primary">Guardar Formación</button>
       </div>
     </div>
-
-    <!-- Reproductor de audio -->
-    <div class="card p-4 mt-4">
-      <h5 class="fw-semibold mb-3 text-primary">Reproductor de Audio</h5>
-      <div id="waveform" class="mb-3"></div>
-      <div class="text-end">
-        <button id="playPauseBtn" class="btn btn-outline-secondary">Reproducir</button>
-      </div>
-    </div>
   </main>
 
   <audio id="audioPlayer" class="d-none" controls></audio>
diff --git a/routes/routines.js b/routes/routines.js
index 5a7ce22..a2fff8c 100644
--- a/routes/routines.js
+++ b/routes/routines.js
@@ -5,20 +5,19 @@ const User = require('./user');
 const multer = require('multer');
 const path = require('path');
 
-// Configuración de almacenamiento para música
 const storage = multer.diskStorage({
   destination: function (req, file, cb) {
     cb(null, 'uploads/music');
   },
   filename: function (req, file, cb) {
-    const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1E9);
+    const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1e9);
     cb(null, uniqueSuffix + path.extname(file.originalname));
   }
 });
 
 const upload = multer({
   storage: storage,
-  limits: { fileSize: 10 * 1024 * 1024 }, // máx 10MB
+  limits: { fileSize: 10 * 1024 * 1024 },
   fileFilter: function (req, file, cb) {
     if (!file.originalname.match(/\.(mp3)$/)) {
       return cb(new Error('Solo se permiten archivos .mp3'));
@@ -39,31 +38,31 @@ const routineSchema = new mongoose.Schema({
   participantes: [{ type: mongoose.Schema.Types.ObjectId, ref: 'User' }],
   elements: [],
   formaciones: [
-  {
-    nombreColoquial: String,
-    notasTacticas: String,
-    duracion: Number,
-    atletas: [
-      {
-        atletaId: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
-        idPersonalizado: String,
-        x: Number,
-        y: Number,
-        rol: String,
-        grupo: String,
-        direccion: {
-          x1: Number,
-          y1: Number,
-          x2: Number,
-          y2: Number
-        },
-        figura: String,
-        tipoElemento: { type: String, enum: ['TRE', 'híbrido', 'transición'], default: 'transición' },
-        codigoElemento: String
-      }
-    ]
-  }
-],
+    {
+      nombreColoquial: String,
+      notasTacticas: String,
+      duracion: Number,
+      atletas: [
+        {
+          atletaId: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
+          idPersonalizado: String,
+          x: Number,
+          y: Number,
+          rol: String,
+          grupo: String,
+          direccion: {
+            x1: Number,
+            y1: Number,
+            x2: Number,
+            y2: Number
+          },
+          figura: String,
+          tipoElemento: { type: String, enum: ['TRE', 'híbrido', 'transición'], default: 'transición' },
+          codigoElemento: String
+        }
+      ]
+    }
+  ],
   createdAt: { type: Date, default: Date.now }
 });
 
@@ -105,7 +104,7 @@ router.get('/:id', async (req, res) => {
   }
 });
 
-// POST agregar formación
+// POST agregar formación (corregido y robusto)
 router.post('/:id/formations', async (req, res) => {
   const { id } = req.params;
   if (!mongoose.Types.ObjectId.isValid(id)) {
@@ -116,13 +115,29 @@ router.post('/:id/formations', async (req, res) => {
     const rutina = await Routine.findById(id);
     if (!rutina) return res.status(404).json({ error: 'Rutina no encontrada' });
 
-    rutina.formaciones.push(req.body);
+    const formacionLimpia = {
+      ...req.body,
+      atletas: req.body.atletas.map(a => {
+        const rawId = typeof a.atletaId === 'object' && a.atletaId?.id ? a.atletaId.id : a.atletaId;
 
-    const nuevosAtletas = req.body.atletas.map(a => a.atletaId);
+        return {
+          ...a,
+          atletaId: mongoose.Types.ObjectId.isValid(rawId)
+            ? new mongoose.Types.ObjectId(rawId)
+            : undefined
+        };
+      }).filter(a => a.atletaId !== undefined)
+    };
 
-    nuevosAtletas.forEach(idAtleta => {
-      if (!rutina.participantes.includes(idAtleta.toString())) {
-        rutina.participantes.push(idAtleta);
+    rutina.formaciones.push(formacionLimpia);
+
+    formacionLimpia.atletas.forEach(({ atletaId }) => {
+      if (
+        atletaId &&
+        mongoose.Types.ObjectId.isValid(atletaId) &&
+        !rutina.participantes.map(p => p.toString()).includes(atletaId.toString())
+      ) {
+        rutina.participantes.push(atletaId);
       }
     });
 
@@ -134,7 +149,6 @@ router.post('/:id/formations', async (req, res) => {
   }
 });
 
-
 // GET formaciones de rutina
 router.get('/:id/formations', async (req, res) => {
   try {
@@ -217,12 +231,10 @@ router.post('/upload/music', upload.single('music'), (req, res) => {
   res.status(200).json({ url: fileUrl });
 });
 
-const { Types } = require('mongoose');
-
 router.delete('/:id', async (req, res) => {
   const { id } = req.params;
 
-  if (!Types.ObjectId.isValid(id)) {
+  if (!mongoose.Types.ObjectId.isValid(id)) {
     return res.status(400).json({ error: 'ID inválido' });
   }
 
@@ -239,7 +251,6 @@ router.delete('/:id', async (req, res) => {
   }
 });
 
-
 // GET rutinas asignadas a un atleta
 router.get('/atleta/:id', async (req, res) => {
   const atletaId = req.params.id;
@@ -254,7 +265,4 @@ router.get('/atleta/:id', async (req, res) => {
   }
 });
 
-
-
-
 module.exports = router;