diff --git a/optuna_dashboard/_app.py b/optuna_dashboard/_app.py
index a72c60c2..48193688 100644
--- a/optuna_dashboard/_app.py
+++ b/optuna_dashboard/_app.py
@@ -158,9 +158,18 @@ def create_new_study(
     return study_id
 
 
-def get_trials(storage: BaseStorage, study_id: int, ttl_seconds: int = 10) -> list[FrozenTrial]:
+def get_trials(storage: BaseStorage, study_id: int) -> list[FrozenTrial]:
     with trials_cache_lock:
         trials = trials_cache.get(study_id, None)
+
+        # Not a big fan of the heuristic, but I can't think of anything better.
+        if trials is None or len(trials) < 100:
+            ttl_seconds = 2
+        elif len(trials) < 500:
+            ttl_seconds = 5
+        else:
+            ttl_seconds = 10
+
         last_fetched_at = trials_last_fetched_at.get(study_id, None)
         if (
             trials is not None
diff --git a/optuna_dashboard/ts/components/StudyDetailBeta.tsx b/optuna_dashboard/ts/components/StudyDetailBeta.tsx
index 400fa5cd..6a7ab839 100644
--- a/optuna_dashboard/ts/components/StudyDetailBeta.tsx
+++ b/optuna_dashboard/ts/components/StudyDetailBeta.tsx
@@ -60,12 +60,23 @@ export const StudyDetailBeta: FC<{
   }, [])
 
   useEffect(() => {
-    if (reloadInterval < 0 || page === "trialTable") {
+    if (reloadInterval < 0) {
       return
     }
+    const nTrials = studyDetail ? studyDetail.trials.length : 0
+    let interval = reloadInterval * 1000
+
+    // For Human-in-the-loop Optimization, the interval is set to 2 seconds
+    // when the number of trials is small and the page is "trialList".
+    if (page === "trialList" && nTrials < 100) {
+      interval = 2000
+    } else if (page === "trialList" && nTrials < 500) {
+      interval = 5000
+    }
+
     const intervalId = setInterval(function () {
       action.updateStudyDetail(studyId)
-    }, reloadInterval * 1000)
+    }, interval)
     return () => clearInterval(intervalId)
   }, [reloadInterval, studyDetail, page])