diff --git a/src/main/services/team/TeamTaskActivityIntervalService.ts b/src/main/services/team/TeamTaskActivityIntervalService.ts
index 68057def..e51415cd 100644
--- a/src/main/services/team/TeamTaskActivityIntervalService.ts
+++ b/src/main/services/team/TeamTaskActivityIntervalService.ts
@@ -27,6 +27,8 @@ interface ResumeMembersCacheEntry {
   signatureKey: string;
 }
 
+type MemberActivityNoopOperation = 'pause-member' | 'resume-member';
+
 type MutableTeamTask = TeamTask & {
   reviewIntervals?: TaskReviewInterval[];
 };
@@ -332,11 +334,34 @@ function writeTaskFile(filePath: string, task: MutableTeamTask): void {
 
 export class TeamTaskActivityIntervalService {
   private readonly resumeMembersCache = new Map<string, ResumeMembersCacheEntry>();
+  private readonly memberActivityNoopCache = new Map<string, string>();
 
   private getBoardStateLockPath(teamName: string): string {
     return `${path.join(getTeamsBasePath(), teamName, 'board-state')}.lock`;
   }
 
+  private getMemberActivityNoopCacheKey(
+    teamName: string,
+    operation: MemberActivityNoopOperation,
+    memberKey: string
+  ): string {
+    return `${teamName}\u0000${operation}\u0000${memberKey}`;
+  }
+
+  private clearMemberActivityNoopCacheForTeam(teamName: string): void {
+    const prefix = `${teamName}\u0000`;
+    for (const key of this.memberActivityNoopCache.keys()) {
+      if (key.startsWith(prefix)) {
+        this.memberActivityNoopCache.delete(key);
+      }
+    }
+  }
+
+  private clearActivityNoopCachesForTeam(teamName: string): void {
+    this.clearMemberActivityNoopCacheForTeam(teamName);
+    this.resumeMembersCache.delete(teamName);
+  }
+
   private mutateTeamTasksWithLock(
     teamName: string,
     run: () => ActivityIntervalResult
@@ -362,7 +387,53 @@ export class TeamTaskActivityIntervalService {
       this.mutateTeamTasksUnlocked(teamName, mutate)
     );
     if (result.changedTasks > 0 || result.failed) {
-      this.resumeMembersCache.delete(teamName);
+      this.clearActivityNoopCachesForTeam(teamName);
+    }
+    return result;
+  }
+
+  private mutateMemberTasksWithNoopCache(
+    teamName: string,
+    operation: MemberActivityNoopOperation,
+    memberKey: string,
+    mutate: (task: MutableTeamTask) => boolean
+  ): ActivityIntervalResult {
+    const cacheKey = this.getMemberActivityNoopCacheKey(teamName, operation, memberKey);
+    const cachedSignatureKey = this.memberActivityNoopCache.get(cacheKey);
+    if (cachedSignatureKey) {
+      const beforeLockSignature = this.readTaskDirectorySignature(teamName);
+      if (
+        beforeLockSignature &&
+        beforeLockSignature.key === cachedSignatureKey &&
+        !fs.existsSync(this.getBoardStateLockPath(teamName))
+      ) {
+        return { changedTasks: 0 };
+      }
+    }
+
+    const result = this.mutateTeamTasksWithLock(teamName, () => {
+      const beforeSignature = this.readTaskDirectorySignature(teamName);
+      if (beforeSignature && this.memberActivityNoopCache.get(cacheKey) === beforeSignature.key) {
+        return { changedTasks: 0 };
+      }
+
+      const mutationResult = this.mutateTeamTasksUnlocked(teamName, mutate);
+      if (mutationResult.changedTasks > 0) {
+        this.clearActivityNoopCachesForTeam(teamName);
+        return mutationResult;
+      }
+
+      const nextSignature = beforeSignature ?? this.readTaskDirectorySignature(teamName);
+      if (nextSignature) {
+        this.memberActivityNoopCache.set(cacheKey, nextSignature.key);
+      } else {
+        this.memberActivityNoopCache.delete(cacheKey);
+      }
+      return mutationResult;
+    });
+
+    if (result.changedTasks > 0 || result.failed) {
+      this.clearActivityNoopCachesForTeam(teamName);
     }
     return result;
   }
@@ -449,13 +520,19 @@ export class TeamTaskActivityIntervalService {
     memberName: string,
     at = new Date().toISOString()
   ): ActivityIntervalResult {
-    return this.mutateTeamTasks(teamName, (task) => {
+    const memberKey = normalizeMemberName(memberName);
+    const mutate = (task: MutableTeamTask): boolean => {
       const changedWork = closeOpenWorkIntervals(task, at, memberName);
       const changedReview = closeOpenReviewIntervals(task, at, memberName);
       const materializedWork = materializePausedWorkInterval(task, at, memberName);
       const materializedReview = materializePausedReviewInterval(task, at, memberName);
       return changedWork || changedReview || materializedWork || materializedReview;
-    });
+    };
+
+    if (!memberKey) {
+      return this.mutateTeamTasks(teamName, mutate);
+    }
+    return this.mutateMemberTasksWithNoopCache(teamName, 'pause-member', memberKey, mutate);
   }
 
   resumeActiveIntervalsForMember(
@@ -466,7 +543,7 @@ export class TeamTaskActivityIntervalService {
     const memberKey = normalizeMemberName(memberName);
     if (!memberKey) return { changedTasks: 0 };
 
-    return this.mutateTeamTasks(teamName, (task) => {
+    return this.mutateMemberTasksWithNoopCache(teamName, 'resume-member', memberKey, (task) => {
       let changed = false;
 
       if (
@@ -599,7 +676,9 @@ export class TeamTaskActivityIntervalService {
     });
 
     if (result.failed) {
-      this.resumeMembersCache.delete(teamName);
+      this.clearActivityNoopCachesForTeam(teamName);
+    } else if (result.changedTasks > 0) {
+      this.clearMemberActivityNoopCacheForTeam(teamName);
     }
     return result;
   }
diff --git a/test/main/services/team/TeamTaskActivityIntervalService.test.ts b/test/main/services/team/TeamTaskActivityIntervalService.test.ts
index 64ea5f34..c5fccfef 100644
--- a/test/main/services/team/TeamTaskActivityIntervalService.test.ts
+++ b/test/main/services/team/TeamTaskActivityIntervalService.test.ts
@@ -585,6 +585,130 @@ describe('TeamTaskActivityIntervalService', () => {
     expect(mutateWithLockSpy).not.toHaveBeenCalled();
   });
 
+  it('skips the task lock after an unchanged single-member resume no-op pass', async () => {
+    await writeTask('alpha', {
+      id: 'bob-task',
+      subject: 'Bob work',
+      owner: 'bob',
+      status: 'in_progress',
+      workIntervals: [{ startedAt: '2026-05-08T10:00:00.000Z' }],
+      historyEvents: [],
+    });
+
+    const service = new TeamTaskActivityIntervalService();
+    expect(
+      service.resumeActiveIntervalsForMember(
+        'alpha',
+        'bob',
+        '2026-05-08T10:20:00.000Z'
+      ).changedTasks
+    ).toBe(0);
+
+    const mutateWithLockSpy = vi.spyOn(
+      TeamTaskActivityIntervalService.prototype as unknown as {
+        mutateTeamTasksWithLock: (
+          teamName: string,
+          run: () => { changedTasks: number; failed?: boolean }
+        ) => { changedTasks: number; failed?: boolean };
+      },
+      'mutateTeamTasksWithLock'
+    );
+    const secondResult = service.resumeActiveIntervalsForMember(
+      'alpha',
+      'bob',
+      '2026-05-08T10:25:00.000Z'
+    );
+
+    expect(secondResult.changedTasks).toBe(0);
+    expect(mutateWithLockSpy).not.toHaveBeenCalled();
+  });
+
+  it('refreshes single-member resume no-op cache when a task file changes', async () => {
+    await writeTask('alpha', {
+      id: 'bob-task',
+      subject: 'Bob work',
+      owner: 'bob',
+      status: 'in_progress',
+      workIntervals: [{ startedAt: '2026-05-08T10:00:00.000Z' }],
+      historyEvents: [],
+    });
+
+    const service = new TeamTaskActivityIntervalService();
+    expect(
+      service.resumeActiveIntervalsForMember(
+        'alpha',
+        'bob',
+        '2026-05-08T10:20:00.000Z'
+      ).changedTasks
+    ).toBe(0);
+
+    await writeTask('alpha', {
+      id: 'bob-task',
+      subject: 'Bob work',
+      owner: 'bob',
+      status: 'in_progress',
+      workIntervals: [
+        {
+          startedAt: '2026-05-08T10:00:00.000Z',
+          completedAt: '2026-05-08T10:05:00.000Z',
+        },
+      ],
+      historyEvents: [],
+      signaturePadding: 'changed-file-signature',
+    });
+
+    const result = service.resumeActiveIntervalsForMember(
+      'alpha',
+      'bob',
+      '2026-05-08T10:30:00.000Z'
+    );
+    const task = await readTask('alpha', 'bob-task');
+
+    expect(result.changedTasks).toBe(1);
+    expect(task.workIntervals).toEqual([
+      { startedAt: '2026-05-08T10:00:00.000Z', completedAt: '2026-05-08T10:05:00.000Z' },
+      { startedAt: '2026-05-08T10:30:00.000Z' },
+    ]);
+  });
+
+  it('skips the task lock after an unchanged single-member pause no-op pass', async () => {
+    await writeTask('alpha', {
+      id: 'alice-task',
+      subject: 'Alice work',
+      owner: 'alice',
+      status: 'in_progress',
+      workIntervals: [{ startedAt: '2026-05-08T10:00:00.000Z' }],
+      historyEvents: [],
+    });
+
+    const service = new TeamTaskActivityIntervalService();
+    expect(
+      service.pauseActiveIntervalsForMember(
+        'alpha',
+        'bob',
+        '2026-05-08T10:20:00.000Z'
+      ).changedTasks
+    ).toBe(0);
+
+    const mutateWithLockSpy = vi.spyOn(
+      TeamTaskActivityIntervalService.prototype as unknown as {
+        mutateTeamTasksWithLock: (
+          teamName: string,
+          run: () => { changedTasks: number; failed?: boolean }
+        ) => { changedTasks: number; failed?: boolean };
+      },
+      'mutateTeamTasksWithLock'
+    );
+    const secondResult = service.pauseActiveIntervalsForMember(
+      'alpha',
+      'bob',
+      '2026-05-08T10:25:00.000Z'
+    );
+
+    expect(secondResult.changedTasks).toBe(0);
+    expect(mutateWithLockSpy).not.toHaveBeenCalled();
+  });
+
   it('refreshes batched resume cache when a task file changes', async () => {
     await writeTask('alpha', {
       id: 'bob-task',