diff --git a/app/models/proxy_exercise.rb b/app/models/proxy_exercise.rb
index f731aa61..84f5e487 100644
--- a/app/models/proxy_exercise.rb
+++ b/app/models/proxy_exercise.rb
@@ -36,8 +36,23 @@ class ProxyExercise < ActiveRecord::Base
           Rails.logger.debug("retrieved assigned exercise for user #{user.id}: Exercise #{assigned_user_proxy_exercise.exercise}" )
           assigned_user_proxy_exercise.exercise
         else
-          Rails.logger.debug("find new matching exercise for user #{user.id}" )
           matching_exercise =
+            if (token.eql? "47f4c736")
+              Rails.logger.debug("Proxy exercise with token 47f4c736, split user in groups..")
+              group = UserGroupSeparator.getGroupWeek2Testing(user)
+              Rails.logger.debug("user assigned to group #{group}")
+              case group
+                when :group_a
+                  exercises.where(id: 348).first
+                when :group_b
+                  exercises.where(id: 349).first
+                when :group_c
+                  exercises.where(id: 350).first
+                when :group_d
+                  exercises.where(id: 351).first
+              end
+            else
+              Rails.logger.debug("find new matching exercise for user #{user.id}" )
               begin
                 find_matching_exercise(user)
               rescue #fallback
@@ -46,8 +61,11 @@ class ProxyExercise < ActiveRecord::Base
                 @reason[:error] = "#{$!}"
                 exercises.shuffle.first
               end
+            end
           user.user_proxy_exercise_exercises << UserProxyExerciseExercise.create(user: user, exercise: matching_exercise, proxy_exercise: self, reason: @reason.to_json)
           matching_exercise
+
+
         end
       recommended_exercise
     end
diff --git a/lib/user_group_separator.rb b/lib/user_group_separator.rb
index 5be05ef6..c49ffe44 100644
--- a/lib/user_group_separator.rb
+++ b/lib/user_group_separator.rb
@@ -24,4 +24,17 @@ class UserGroupSeparator
     end
   end
 
+  def self.getGroupWeek2Testing(user)
+    groupById = user.id % 4
+    if groupById == 0
+      :group_a
+    elsif groupById == 1
+      :group_b
+    elsif groupById == 2
+      :group_c
+    else # 3
+      :group_d
+    end
+  end
+
 end
\ No newline at end of file