diff --git a/Sources/HeartTrack/HeartTrack.csproj b/Sources/HeartTrack/HeartTrack.csproj
index 723d747..205c632 100644
--- a/Sources/HeartTrack/HeartTrack.csproj
+++ b/Sources/HeartTrack/HeartTrack.csproj
@@ -17,6 +17,10 @@
 
   <ItemGroup>
     <Folder Include="Components\" />
+    <Folder Include="Services\ActivityDataService\" />
   </ItemGroup>
 
+  <ItemGroup>
+    <None Remove="Services\ActivityDataService\" />
+  </ItemGroup>
 </Project>
diff --git a/Sources/HeartTrack/Services/ActivityDataService/ActivityDataService.cs b/Sources/HeartTrack/Services/ActivityDataService/ActivityDataService.cs
new file mode 100644
index 0000000..1dc34a6
--- /dev/null
+++ b/Sources/HeartTrack/Services/ActivityDataService/ActivityDataService.cs
@@ -0,0 +1,11 @@
+using System;
+namespace HeartTrack.Services.ActivityDataService
+{
+	public class ActivityDataService
+	{
+		public ActivityDataService()
+		{
+		}
+	}
+}
+
diff --git a/Sources/HeartTrack/Services/ActivityDataService/IActivityDataService.cs b/Sources/HeartTrack/Services/ActivityDataService/IActivityDataService.cs
new file mode 100644
index 0000000..030e2af
--- /dev/null
+++ b/Sources/HeartTrack/Services/ActivityDataService/IActivityDataService.cs
@@ -0,0 +1,23 @@
+using System;
+using System.Diagnostics;
+using HeartTrack.Models;
+
+namespace HeartTrack.Services.ActivityDataService
+{
+    public interface IActivityDataService
+    {
+        public Task<List<Activity>> getAllActivities();
+
+        public Task SaveAllActivities(List<Activity> list);
+
+        public Task resetDataActivities();
+        public Task AddActivity(Activity u);
+
+        public Task RemoveActivity(Activity u);
+
+        public Task UpdateActivity(Activity u);
+
+        public Task<Activity> getActivityById(String pseudo);
+    }
+}
+