diff --git a/src/app.py b/src/app.py
index 4ebb1d9..b1d6e5f 100644
--- a/src/app.py
+++ b/src/app.py
@@ -38,6 +38,45 @@
         "schedule": "Mondays, Wednesdays, Fridays, 2:00 PM - 3:00 PM",
         "max_participants": 30,
         "participants": ["john@mergington.edu", "olivia@mergington.edu"]
+    },
+    # Sports related activities
+    "Soccer Team": {
+        "description": "Join the school soccer team and compete in local leagues",
+        "schedule": "Tuesdays and Thursdays, 4:00 PM - 5:30 PM",
+        "max_participants": 18,
+        "participants": ["lucas@mergington.edu", "mia@mergington.edu"]
+    },
+    "Basketball Club": {
+        "description": "Practice basketball skills and play friendly matches",
+        "schedule": "Wednesdays, 3:30 PM - 5:00 PM",
+        "max_participants": 15,
+        "participants": ["liam@mergington.edu", "ava@mergington.edu"]
+    },
+    # Artistic activities
+    "Art Club": {
+        "description": "Explore painting, drawing, and other visual arts",
+        "schedule": "Mondays, 3:30 PM - 5:00 PM",
+        "max_participants": 16,
+        "participants": ["ella@mergington.edu", "noah@mergington.edu"]
+    },
+    "Drama Society": {
+        "description": "Participate in theater productions and acting workshops",
+        "schedule": "Fridays, 4:00 PM - 6:00 PM",
+        "max_participants": 20,
+        "participants": ["amelia@mergington.edu", "jack@mergington.edu"]
+    },
+    # Intellectual activities
+    "Math Olympiad": {
+        "description": "Prepare for math competitions and solve challenging problems",
+        "schedule": "Thursdays, 3:30 PM - 5:00 PM",
+        "max_participants": 14,
+        "participants": ["charlotte@mergington.edu", "benjamin@mergington.edu"]
+    },
+    "Debate Club": {
+        "description": "Develop public speaking and argumentation skills",
+        "schedule": "Wednesdays, 4:00 PM - 5:30 PM",
+        "max_participants": 12,
+        "participants": ["henry@mergington.edu", "grace@mergington.edu"]
     }
 }
 
@@ -61,7 +100,9 @@ def signup_for_activity(activity_name: str, email: str):
 
     # Get the specific activity
     activity = activities[activity_name]
+# Validate student is not already signed up
 
+    if email in activity["participants"]:
     # Add student
     activity["participants"].append(email)
     return {"message": f"Signed up {email} for {activity_name}"}
diff --git a/src/static/app.js b/src/static/app.js
index dcc1e38..94ed958 100644
--- a/src/static/app.js
+++ b/src/static/app.js
@@ -20,11 +20,32 @@ document.addEventListener("DOMContentLoaded", () => {
 
         const spotsLeft = details.max_participants - details.participants.length;
 
+        // Build participants list HTML
+        let participantsHTML = "";
+        if (details.participants && details.participants.length > 0) {
+          participantsHTML = `
+            <div class="participants-section">
+              <strong>Participants:</strong>
+              <ul class="participants-list">
+                ${details.participants.map(email => `<li>${email}</li>`).join("")}
+              </ul>
+            </div>
+          `;
+        } else {
+          participantsHTML = `
+            <div class="participants-section">
+              <strong>Participants:</strong>
+              <span class="no-participants">No participants yet</span>
+            </div>
+          `;
+        }
+
         activityCard.innerHTML = `
           <h4>${name}</h4>
           <p>${details.description}</p>
           <p><strong>Schedule:</strong> ${details.schedule}</p>
           <p><strong>Availability:</strong> ${spotsLeft} spots left</p>
+          ${participantsHTML}
         `;
 
         activitiesList.appendChild(activityCard);
diff --git a/src/static/styles.css b/src/static/styles.css
index a533b32..54254db 100644
--- a/src/static/styles.css
+++ b/src/static/styles.css
@@ -142,3 +142,31 @@ footer {
   padding: 20px;
   color: #666;
 }
+
+.participants-section {
+  margin-top: 12px;
+  padding: 10px;
+  background-color: #eef3fb;
+  border-radius: 4px;
+  border: 1px solid #c5cae9;
+}
+
+.participants-section strong {
+  color: #3949ab;
+  display: block;
+  margin-bottom: 6px;
+}
+
+.participants-list {
+  list-style-type: disc;
+  margin-left: 20px;
+  margin-bottom: 0;
+  color: #333;
+  font-size: 15px;
+}
+
+.no-participants {
+  color: #888;
+  font-style: italic;
+  margin-left: 4px;
+}