diff --git a/app/routes/logging.py b/app/routes/logging.py
index 9b753e2..146f562 100644
--- a/app/routes/logging.py
+++ b/app/routes/logging.py
@@ -14,6 +14,7 @@ from sqlmodel import Session
 from app.database import get_db_session
 from app.models.user import User
 from app.services.log_service import LogService
+from app.services.progression_service import ProgressionService
 from app.services.workout_session_service import WorkoutSessionService
 from app.utils.auth import get_current_admin_user, get_active_profile_id
 
@@ -80,6 +81,10 @@ async def log_set(
     logs = log_service.list_logs_for_exercise(ws.id, exercise_id)
     next_set = len(logs) + 1
 
+    # Fetch suggestion for pre-filling the next set form
+    progression = ProgressionService(session)
+    suggestion = progression.get_suggestion(active_profile_id, exercise_id)
+
     templates = request.app.state.templates
     return templates.TemplateResponse("partials/log_entry.html", {
         "request": request,
@@ -88,6 +93,8 @@ async def log_set(
         "workout_day_id": workout_day_id,
         "next_set": next_set,
         "session_id": ws.id,
+        "suggested_reps": suggestion.get("suggested_reps"),
+        "suggested_weight": suggestion.get("suggested_weight"),
     })
 
 
@@ -124,6 +131,13 @@ async def edit_log(
     logs = log_service.list_logs_for_exercise(log.session_id, log.exercise_id)
     next_set = len(logs) + 1
 
+    # Fetch suggestion for pre-filling the next set form
+    active_profile_id = get_active_profile_id(request)
+    suggestion = {}
+    if active_profile_id:
+        progression = ProgressionService(session)
+        suggestion = progression.get_suggestion(active_profile_id, log.exercise_id)
+
     templates = request.app.state.templates
     return templates.TemplateResponse("partials/log_entry.html", {
         "request": request,
@@ -132,6 +146,8 @@ async def edit_log(
         "workout_day_id": 0,
         "next_set": next_set,
         "session_id": log.session_id,
+        "suggested_reps": suggestion.get("suggested_reps"),
+        "suggested_weight": suggestion.get("suggested_weight"),
     })
 
 
@@ -164,6 +180,13 @@ async def delete_log(
         logs = log_service.list_logs_for_exercise(session_id, exercise_id)
         next_set = len(logs) + 1
 
+        # Fetch suggestion for pre-filling the next set form
+        active_profile_id = get_active_profile_id(request)
+        suggestion = {}
+        if active_profile_id:
+            progression = ProgressionService(session)
+            suggestion = progression.get_suggestion(active_profile_id, exercise_id)
+
         templates = request.app.state.templates
         return templates.TemplateResponse("partials/log_entry.html", {
             "request": request,
@@ -172,6 +195,8 @@ async def delete_log(
             "workout_day_id": 0,
             "next_set": next_set,
             "session_id": session_id,
+            "suggested_reps": suggestion.get("suggested_reps"),
+            "suggested_weight": suggestion.get("suggested_weight"),
         })
 
     return HTMLResponse("")
diff --git a/app/templates/partials/exercise_card.html b/app/templates/partials/exercise_card.html
index 4f20536..bd9df54 100644
--- a/app/templates/partials/exercise_card.html
+++ b/app/templates/partials/exercise_card.html
@@ -32,6 +32,10 @@
     <!-- Inline logging (Phase 4) -->
     {% if active_profile %}
     <div id="logs-exercise-{{ exercise.id }}">
+        {% if suggestions and suggestions[exercise.id] %}
+            {% set suggested_reps = suggestions[exercise.id].suggested_reps %}
+            {% set suggested_weight = suggestions[exercise.id].suggested_weight %}
+        {% endif %}
         {% if existing_logs and existing_logs[exercise.id] %}
             {% set logs = existing_logs[exercise.id] %}
             {% set exercise_id = exercise.id %}
diff --git a/app/templates/partials/log_form.html b/app/templates/partials/log_form.html
index c34613d..2cac77b 100644
--- a/app/templates/partials/log_form.html
+++ b/app/templates/partials/log_form.html
@@ -11,9 +11,11 @@
         <small style="white-space:nowrap; opacity:0.7;">Set {{ next_set|default(1) }}</small>
         <input type="number" name="reps" placeholder="Reps"
                min="0" max="100" required
+               {% if suggested_reps %}value="{{ suggested_reps }}"{% endif %}
                style="width:5rem; margin-bottom:0;">
         <input type="text" name="weight" placeholder="Weight (lbs)"
                required
+               {% if suggested_weight %}value="{{ suggested_weight }}"{% endif %}
                style="width:8rem; margin-bottom:0;">
         <label style="display:flex; align-items:center; gap:0.3rem; margin-bottom:0; white-space:nowrap;">
             <input type="checkbox" name="felt_easy" role="switch" style="margin-bottom:0;">
diff --git a/tests/test_auth_dependency.py b/tests/test_auth_dependency.py
index 31ea86c..c75a190 100644
--- a/tests/test_auth_dependency.py
+++ b/tests/test_auth_dependency.py
@@ -3,25 +3,27 @@
 from unittest.mock import MagicMock
 
 import pytest
-from fastapi import HTTPException
 
-from app.utils.auth import get_current_admin_user, get_active_profile_id
+from app.utils.auth import (
+    NotAuthenticatedError,
+    get_current_admin_user,
+    get_active_profile_id,
+)
 
 
 class TestAuthDependency:
     """Tests for the require_admin dependency."""
 
     def test_redirects_when_no_session_cookie(self) -> None:
-        """Should redirect to /login (303) when no session cookie is present."""
+        """Should raise NotAuthenticatedError when no session cookie is present."""
         request = MagicMock()
         request.cookies = {}
 
-        with pytest.raises(HTTPException) as exc_info:
+        with pytest.raises(NotAuthenticatedError):
             get_current_admin_user(request=request, session=MagicMock())
-        assert exc_info.value.status_code == 303
 
     def test_redirects_when_invalid_token(self) -> None:
-        """Should redirect to /login (303) when session cookie has invalid token."""
+        """Should raise NotAuthenticatedError when session cookie has invalid token."""
         request = MagicMock()
         request.cookies = {"session": "invalid-token"}
         request.app.state.secret_key = "test-secret"
@@ -29,9 +31,8 @@ class TestAuthDependency:
         mock_session = MagicMock()
         mock_session.get.return_value = None
 
-        with pytest.raises(HTTPException) as exc_info:
+        with pytest.raises(NotAuthenticatedError):
             get_current_admin_user(request=request, session=mock_session)
-        assert exc_info.value.status_code == 303
 
 
 class TestGetActiveProfileId:
diff --git a/tests/test_dashboard_routes.py b/tests/test_dashboard_routes.py
index 07819cc..a66bbb1 100644
--- a/tests/test_dashboard_routes.py
+++ b/tests/test_dashboard_routes.py
@@ -9,7 +9,7 @@ class TestDashboard:
     def test_dashboard_requires_auth(self, client: TestClient) -> None:
         """GET /dashboard should require admin login."""
         response = client.get("/dashboard", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestExerciseProgress:
@@ -18,4 +18,4 @@ class TestExerciseProgress:
     def test_exercise_progress_requires_auth(self, client: TestClient) -> None:
         """GET /dashboard/exercise/1 should require admin login."""
         response = client.get("/dashboard/exercise/1", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
diff --git a/tests/test_exercise_routes.py b/tests/test_exercise_routes.py
index d837fef..b70f5df 100644
--- a/tests/test_exercise_routes.py
+++ b/tests/test_exercise_routes.py
@@ -9,7 +9,7 @@ class TestExerciseBrowser:
     def test_exercise_browser_requires_auth(self, client: TestClient) -> None:
         """GET /exercises should require admin login."""
         response = client.get("/exercises", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestExerciseSearch:
@@ -21,4 +21,4 @@ class TestExerciseSearch:
             "/exercises/search?workout_day=Push",
             follow_redirects=False,
         )
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
diff --git a/tests/test_history_routes.py b/tests/test_history_routes.py
index d123100..a424abb 100644
--- a/tests/test_history_routes.py
+++ b/tests/test_history_routes.py
@@ -9,7 +9,7 @@ class TestLogHistory:
     def test_history_requires_auth(self, client: TestClient) -> None:
         """GET /history should require admin login."""
         response = client.get("/history", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestSessionDetail:
@@ -18,4 +18,4 @@ class TestSessionDetail:
     def test_session_detail_requires_auth(self, client: TestClient) -> None:
         """GET /history/1 should require admin login."""
         response = client.get("/history/1", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
diff --git a/tests/test_logging_routes.py b/tests/test_logging_routes.py
index 8def686..e00fe39 100644
--- a/tests/test_logging_routes.py
+++ b/tests/test_logging_routes.py
@@ -19,7 +19,7 @@ class TestLogSet:
             },
             follow_redirects=False,
         )
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestLogEdit:
@@ -32,7 +32,7 @@ class TestLogEdit:
             data={"reps": "10", "weight": "35 lbs"},
             follow_redirects=False,
         )
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestLogDelete:
@@ -41,4 +41,4 @@ class TestLogDelete:
     def test_delete_log_requires_auth(self, client: TestClient) -> None:
         """POST /log/1/delete should require admin login."""
         response = client.post("/log/1/delete", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
diff --git a/tests/test_profile_routes.py b/tests/test_profile_routes.py
index c66180c..855d572 100644
--- a/tests/test_profile_routes.py
+++ b/tests/test_profile_routes.py
@@ -14,7 +14,7 @@ class TestProfileSwitcher:
             follow_redirects=False,
         )
         # Should redirect to login or return 401
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestProfileList:
@@ -23,4 +23,4 @@ class TestProfileList:
     def test_profiles_page_requires_auth(self, client: TestClient) -> None:
         """GET /profiles should require admin login."""
         response = client.get("/profiles", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
diff --git a/tests/test_schedule_routes.py b/tests/test_schedule_routes.py
index 142d518..92dc50f 100644
--- a/tests/test_schedule_routes.py
+++ b/tests/test_schedule_routes.py
@@ -9,4 +9,4 @@ class TestSchedule:
     def test_schedule_requires_auth(self, client: TestClient) -> None:
         """GET /schedule should require admin login."""
         response = client.get("/schedule", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
diff --git a/tests/test_workout_routes.py b/tests/test_workout_routes.py
index 750cf9b..618fb1e 100644
--- a/tests/test_workout_routes.py
+++ b/tests/test_workout_routes.py
@@ -9,9 +9,9 @@ class TestWorkoutDayViewer:
     def test_workout_day_requires_auth(self, client: TestClient) -> None:
         """GET /workouts/push should require admin login."""
         response = client.get("/workouts/push", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
     def test_workout_days_list_requires_auth(self, client: TestClient) -> None:
         """GET /workouts should require admin login."""
         response = client.get("/workouts", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)