diff --git a/brax/envs/wrappers/training.py b/brax/envs/wrappers/training.py
index e6383c6b3..78a3a54f2 100644
--- a/brax/envs/wrappers/training.py
+++ b/brax/envs/wrappers/training.py
@@ -98,10 +98,20 @@ def reset(self, rng: jax.Array) -> State:
   def step(self, state: State, action: jax.Array) -> State:
     def f(state, _):
       nstate = self.env.step(state, action)
-      return nstate, nstate.reward
+      return nstate, (nstate.reward, nstate.metrics)
 
-    state, rewards = jax.lax.scan(f, state, (), self.action_repeat)
+    state, (rewards, all_metrics) = jax.lax.scan(
+        f, state, (), self.action_repeat
+    )
     state = state.replace(reward=jp.sum(rewards, axis=0))
+    # Sum per-step metrics across action-repeat sub-steps so that
+    # sparse or per-step metrics (e.g. action-change penalties) are
+    # correctly accumulated instead of only reflecting the last
+    # sub-step.  See #610.
+    summed_metrics = jax.tree_util.tree_map(
+        lambda m: jp.sum(m, axis=0), all_metrics
+    )
+    state = state.replace(metrics=summed_metrics)
     steps = state.info['steps'] + self.action_repeat
     one = jp.ones_like(state.done)
     zero = jp.zeros_like(state.done)
@@ -257,4 +267,4 @@ def step(sys, s, a):
     res = jax.vmap(step, in_axes=[self._in_axes, 0, 0])(
         self._sys_v, state, action
     )
-    return res
+    return res
\ No newline at end of file