diff --git a/backend/controllers/memberActivityController.js b/backend/controllers/memberActivityController.js
index beb2e65..96359e2 100644
--- a/backend/controllers/memberActivityController.js
+++ b/backend/controllers/memberActivityController.js
@@ -204,17 +204,22 @@ export const getMemberActivities = async (req, res) => {
             
             const activity = ma.activity.predefinedActivity;
             const activityName = activity.name;
+            const activityCode = activity.code || activity.name; // Verwende Code falls vorhanden, sonst Name
             const date = ma.activity.diaryDate?.date;
             
-            if (!activityMap.has(activityName)) {
-                activityMap.set(activityName, {
-                    name: activityName,
+            // Verwende Code als Key, falls vorhanden, sonst Name
+            const key = activityCode;
+            
+            if (!activityMap.has(key)) {
+                activityMap.set(key, {
+                    name: activityName, // Vollständiger Name für Tooltip
+                    code: activityCode, // Code/Kürzel für Anzeige
                     count: 0,
                     dates: []
                 });
             }
             
-            const activityData = activityMap.get(activityName);
+            const activityData = activityMap.get(key);
             activityData.count++;
             if (date) {
                 activityData.dates.push(date);
@@ -403,7 +408,9 @@ export const getMemberLastParticipations = async (req, res) => {
             .forEach(ma => {
                 const date = ma.activity.diaryDate.date;
                 const diaryDateId = ma.activity.diaryDate.id;
-                const activityName = ma.activity.predefinedActivity.name;
+                const activity = ma.activity.predefinedActivity;
+                const activityName = activity.name;
+                const activityCode = activity.code || activity.name;
                 
                 if (!participationsByDate.has(date)) {
                     participationsByDate.set(date, {
@@ -415,8 +422,13 @@ export const getMemberLastParticipations = async (req, res) => {
                 
                 const dateEntry = participationsByDate.get(date);
                 // Füge Aktivität nur hinzu, wenn sie noch nicht vorhanden ist (vermeide Duplikate)
-                if (!dateEntry.activities.find(a => a === activityName)) {
-                    dateEntry.activities.push(activityName);
+                // Speichere sowohl code als auch name
+                const activityEntry = {
+                    code: activityCode,
+                    name: activityName
+                };
+                if (!dateEntry.activities.find(a => (a.code || a.name) === activityCode)) {
+                    dateEntry.activities.push(activityEntry);
                 }
             });
         
@@ -432,10 +444,11 @@ export const getMemberLastParticipations = async (req, res) => {
         // Formatiere für das Frontend: Flache Liste mit Datum und Aktivität
         const participations = [];
         sortedDates.forEach(dateEntry => {
-            dateEntry.activities.forEach(activityName => {
+            dateEntry.activities.forEach(activity => {
                 participations.push({
                     id: null, // Virtuell
-                    activityName: activityName,
+                    activityName: activity.code || activity.name, // Code für Anzeige
+                    activityFullName: activity.name, // Vollständiger Name für Tooltip
                     date: dateEntry.date,
                     diaryDateId: dateEntry.diaryDateId
                 });
diff --git a/frontend/src/components/MemberActivityStatsDialog.vue b/frontend/src/components/MemberActivityStatsDialog.vue
index a36979a..0044c36 100644
--- a/frontend/src/components/MemberActivityStatsDialog.vue
+++ b/frontend/src/components/MemberActivityStatsDialog.vue
@@ -15,7 +15,7 @@
             <div class="participation-date-header">{{ formatDate(dateGroup.date) }}</div>
             <div class="participation-activities">
               <div v-for="(activity, index) in dateGroup.activities" :key="index" class="participation-item">
-                <div class="participation-name">{{ activity }}</div>
+                <div class="participation-name" :title="getActivityTooltip(activity)">{{ getActivityDisplay(activity) }}</div>
               </div>
             </div>
           </div>
@@ -29,8 +29,8 @@
       <div class="section">
         <h3 class="section-title">Statistik der Übungen</h3>
         <div v-if="activityStats && activityStats.length" class="stats-list">
-          <div v-for="stat in activityStats" :key="stat.name" class="stat-item">
-            <div class="stat-name">{{ stat.name }}</div>
+          <div v-for="stat in activityStats" :key="stat.code || stat.name" class="stat-item">
+            <div class="stat-name" :title="stat.name">{{ stat.code || stat.name }}</div>
             <div class="stat-count">{{ stat.count }}x</div>
           </div>
         </div>
@@ -87,8 +87,19 @@ export default {
         }
         const dateGroup = grouped.get(date);
         // Füge Aktivität nur hinzu, wenn sie noch nicht vorhanden ist
-        if (!dateGroup.activities.includes(participation.activityName)) {
-          dateGroup.activities.push(participation.activityName);
+        // Unterstütze sowohl alte (String) als auch neue (Objekt) Datenstruktur
+        const activityEntry = participation.activityFullName 
+          ? { code: participation.activityName, name: participation.activityFullName }
+          : participation.activityName;
+        
+        const exists = typeof activityEntry === 'string'
+          ? dateGroup.activities.includes(activityEntry)
+          : dateGroup.activities.some(a => 
+              (typeof a === 'string' ? a === activityEntry.code : (a.code || a.name) === activityEntry.code)
+            );
+        
+        if (!exists) {
+          dateGroup.activities.push(activityEntry);
         }
       });
       
@@ -111,6 +122,22 @@ export default {
       if (!dateString) return '';
       const date = new Date(dateString);
       return date.toLocaleDateString('de-DE');
+    },
+    getActivityDisplay(activity) {
+      // Wenn activity ein String ist (alte Datenstruktur), verwende es direkt
+      if (typeof activity === 'string') {
+        return activity;
+      }
+      // Wenn activity ein Objekt ist, verwende code oder name
+      return activity.code || activity.name || activity;
+    },
+    getActivityTooltip(activity) {
+      // Wenn activity ein String ist (alte Datenstruktur), kein Tooltip
+      if (typeof activity === 'string') {
+        return '';
+      }
+      // Wenn activity ein Objekt ist, verwende name als Tooltip
+      return activity.name || '';
     }
   }
 };
diff --git a/package-lock.json b/package-lock.json
index be8b2c4..0a023a2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4018,9 +4018,9 @@
       "license": "MIT"
     },
     "node_modules/js-yaml": {
-      "version": "4.1.0",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.0.tgz",
-      "integrity": "sha512-wpxZs9NoxZaJESJGIZTyDEaYpl0FKSA+FB9aJiyemKhMwkxQg63h4T1KJgUGHpTqPDNRcmmYLugrRjJlBtWvRA==",
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.1.1.tgz",
+      "integrity": "sha512-qQKT4zQxXl8lLwBtHMWwaTcGfFOZviOJet3Oy/xmGk2gZH677CJM9EvtfdSkgWcATZhj/55JZ0rmy3myCT5lsA==",
       "license": "MIT",
       "dependencies": {
         "argparse": "^2.0.1"