diff --git a/src/app.py b/src/app.py
index 4ebb1d9..1285954 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 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": 22,
+        "participants": ["lucas@mergington.edu", "mia@mergington.edu"]
+    },
+    "Basketball Club": {
+        "description": "Practice basketball and participate in tournaments",
+        "schedule": "Wednesdays, 3:30 PM - 5:00 PM",
+        "max_participants": 15,
+        "participants": ["liam@mergington.edu", "ava@mergington.edu"]
+    },
+    # Artistic activities
+    "Art Workshop": {
+        "description": "Explore painting, drawing, and sculpture techniques",
+        "schedule": "Mondays, 4:00 PM - 5:30 PM",
+        "max_participants": 18,
+        "participants": ["noah@mergington.edu", "isabella@mergington.edu"]
+    },
+    "Drama Club": {
+        "description": "Act, direct, and produce school plays and performances",
+        "schedule": "Fridays, 3:30 PM - 5:30 PM",
+        "max_participants": 20,
+        "participants": ["amelia@mergington.edu", "benjamin@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": 16,
+        "participants": ["charlotte@mergington.edu", "elijah@mergington.edu"]
+    },
+    "Debate Team": {
+        "description": "Develop public speaking and argumentation skills",
+        "schedule": "Wednesdays, 4:00 PM - 5:30 PM",
+        "max_participants": 14,
+        "participants": ["jack@mergington.edu", "harper@mergington.edu"]
     }
 }
 
@@ -62,6 +101,10 @@ def signup_for_activity(activity_name: str, email: str):
     # Get the specific activity
     activity = activities[activity_name]
 
+    # Check if student already signed up
+    if email in activity["participants"]:
+        raise HTTPException(status_code=400, detail="Student already signed up for this activity")
+
     # 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..d0ba62a 100644
--- a/src/static/app.js
+++ b/src/static/app.js
@@ -15,18 +15,7 @@ document.addEventListener("DOMContentLoaded", () => {
 
       // Populate activities list
       Object.entries(activities).forEach(([name, details]) => {
-        const activityCard = document.createElement("div");
-        activityCard.className = "activity-card";
-
-        const spotsLeft = details.max_participants - details.participants.length;
-
-        activityCard.innerHTML = `
-          <h4>${name}</h4>
-          <p>${details.description}</p>
-          <p><strong>Schedule:</strong> ${details.schedule}</p>
-          <p><strong>Availability:</strong> ${spotsLeft} spots left</p>
-        `;
-
+        const activityCard = renderActivityCard(name, details);
         activitiesList.appendChild(activityCard);
 
         // Add option to select dropdown
@@ -41,6 +30,46 @@ document.addEventListener("DOMContentLoaded", () => {
     }
   }
 
+  // Render activity card
+  function renderActivityCard(name, details) {
+    const card = document.createElement("div");
+    card.className = "activity-card";
+
+    const spotsLeft = details.max_participants - details.participants.length;
+
+    card.innerHTML = `
+      <h4>${name}</h4>
+      <p>${details.description}</p>
+      <p><strong>Schedule:</strong> ${details.schedule}</p>
+      <p><strong>Availability:</strong> ${spotsLeft} spots left</p>
+    `;
+
+    // Participants section
+    const participantsSection = document.createElement("div");
+    participantsSection.className = "participants-section";
+    const participantsTitle = document.createElement("h4");
+    participantsTitle.textContent = "Participants";
+    participantsSection.appendChild(participantsTitle);
+    const participantsList = document.createElement("ul");
+    participantsList.className = "participants-list";
+    if (details.participants && details.participants.length > 0) {
+      details.participants.forEach((participant) => {
+        const li = document.createElement("li");
+        li.textContent = participant;
+        participantsList.appendChild(li);
+      });
+    } else {
+      const li = document.createElement("li");
+      li.textContent = "No participants yet.";
+      li.className = "no-participants";
+      participantsList.appendChild(li);
+    }
+    participantsSection.appendChild(participantsList);
+    card.appendChild(participantsSection);
+
+    return card;
+  }
+
   // Handle form submission
   signupForm.addEventListener("submit", async (event) => {
     event.preventDefault();
diff --git a/src/static/styles.css b/src/static/styles.css
index a533b32..30dde86 100644
--- a/src/static/styles.css
+++ b/src/static/styles.css
@@ -142,3 +142,30 @@ footer {
   padding: 20px;
   color: #666;
 }
+
+.participants-section {
+  background: #f8f9fa;
+  border-radius: 8px;
+  margin-top: 1em;
+  padding: 1em;
+  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
+}
+
+.participants-section h4 {
+  margin: 0 0 0.5em 0;
+  font-size: 1.1em;
+  color: #333;
+  letter-spacing: 0.5px;
+}
+
+.participants-list {
+  list-style: disc inside;
+  margin: 0;
+  padding-left: 1em;
+  color: #444;
+}
+
+.participants-list li.no-participants {
+  color: #aaa;
+  font-style: italic;
+}