diff --git a/src/db/hooks/useVolumeStats.ts b/src/db/hooks/useVolumeStats.ts
index 411b240..00f9450 100644
--- a/src/db/hooks/useVolumeStats.ts
+++ b/src/db/hooks/useVolumeStats.ts
@@ -3,7 +3,7 @@
  */
 
 import { useMemo } from 'react';
-import { useWorkouts } from './useWorkouts';
+import { useWorkouts, type ViewMode } from './useWorkouts';
 import { useProfile } from './useProfiles';
 import { useExerciseMappings } from './useExerciseMappings';
 import { calculateMuscleVolume, aggregateToFunctionalGroups } from '@core/volume-calculator';
@@ -110,19 +110,27 @@ function convertSets(dbSets: WorkoutSet[]): WorkoutSet[] {
   return dbSets;
 }
 
+export type { ViewMode };
+
 /**
  * Get volume statistics at the ScientificMuscle level
+ * @param profileId - Profile ID
+ * @param daysBackOrMode - Number of days back (legacy) or ViewMode ('last7days' | 'calendarWeek')
  */
 export function useScientificMuscleVolume(
   profileId: string | null,
-  daysBack: number = 7
+  daysBackOrMode: number | ViewMode = 7
 ): {
   stats: VolumeStatItem[];
   totalVolume: number;
   isLoading: boolean;
   error: Error | null;
 } {
-  const { workouts, isLoading: workoutsLoading, error } = useWorkouts(profileId, daysBack);
+  // Convert to options format for useWorkouts
+  const workoutsArg = typeof daysBackOrMode === 'number'
+    ? daysBackOrMode
+    : { mode: daysBackOrMode };
+  const { workouts, isLoading: workoutsLoading, error } = useWorkouts(profileId, workoutsArg);
   const { profile } = useProfile(profileId);
   const { mappings: userMappings, isLoading: mappingsLoading } = useExerciseMappings(profileId);
 
@@ -161,10 +169,12 @@ export function useScientificMuscleVolume(
 
 /**
  * Get volume statistics at the FunctionalGroup level
+ * @param profileId - Profile ID
+ * @param daysBackOrMode - Number of days back (legacy) or ViewMode ('last7days' | 'calendarWeek')
  */
 export function useFunctionalGroupVolume(
   profileId: string | null,
-  daysBack: number = 7
+  daysBackOrMode: number | ViewMode = 7
 ): {
   stats: VolumeStatItem[];
   totalVolume: number;
@@ -172,7 +182,11 @@ export function useFunctionalGroupVolume(
   isLoading: boolean;
   error: Error | null;
 } {
-  const { workouts, isLoading: workoutsLoading, error } = useWorkouts(profileId, daysBack);
+  // Convert to options format for useWorkouts
+  const workoutsArg = typeof daysBackOrMode === 'number'
+    ? daysBackOrMode
+    : { mode: daysBackOrMode };
+  const { workouts, isLoading: workoutsLoading, error } = useWorkouts(profileId, workoutsArg);
   const { profile } = useProfile(profileId);
   const { mappings: userMappings, isLoading: mappingsLoading } = useExerciseMappings(profileId);
 
@@ -232,17 +246,20 @@ export function useFunctionalGroupVolume(
 
 /**
  * Get the breakdown of scientific muscles within a functional group
+ * @param profileId - Profile ID
+ * @param functionalGroup - Functional group to get breakdown for
+ * @param daysBackOrMode - Number of days back (legacy) or ViewMode ('last7days' | 'calendarWeek')
  */
 export function useFunctionalGroupBreakdown(
   profileId: string | null,
   functionalGroup: FunctionalGroup,
-  daysBack: number = 7
+  daysBackOrMode: number | ViewMode = 7
 ): {
   breakdown: VolumeStatItem[];
   isLoading: boolean;
   error: Error | null;
 } {
-  const { stats, isLoading, error } = useScientificMuscleVolume(profileId, daysBack);
+  const { stats, isLoading, error } = useScientificMuscleVolume(profileId, daysBackOrMode);
   const { profile } = useProfile(profileId);
 
   const breakdown = useMemo(() => {
diff --git a/src/db/hooks/useWorkouts.ts b/src/db/hooks/useWorkouts.ts
index a00f5a2..243555f 100644
--- a/src/db/hooks/useWorkouts.ts
+++ b/src/db/hooks/useWorkouts.ts
@@ -7,6 +7,8 @@ import { db, generateId, type Workout, type WorkoutSet } from '../schema';
 
 const WORKOUTS_KEY = ['workouts'];
 
+export type ViewMode = 'last7days' | 'calendarWeek';
+
 /**
  * Get the start of today in the user's local timezone
  */
@@ -15,25 +17,76 @@ function getStartOfToday(): Date {
   return new Date(now.getFullYear(), now.getMonth(), now.getDate());
 }
 
+/**
+ * Get the end of today in the user's local timezone (23:59:59.999)
+ */
+function getEndOfToday(): Date {
+  const now = new Date();
+  return new Date(now.getFullYear(), now.getMonth(), now.getDate(), 23, 59, 59, 999);
+}
+
+/**
+ * Get the start of the current calendar week (Monday)
+ */
+function getStartOfWeek(): Date {
+  const now = new Date();
+  const day = now.getDay();
+  const diff = day === 0 ? -6 : 1 - day; // Adjust when Sunday (0)
+  const monday = new Date(now);
+  monday.setDate(now.getDate() + diff);
+  return new Date(monday.getFullYear(), monday.getMonth(), monday.getDate());
+}
+
+export interface UseWorkoutsOptions {
+  mode?: ViewMode;
+}
+
 /**
  * Get workouts for a profile within a date range
+ * @param profileId - Profile ID
+ * @param daysBackOrOptions - Number of days back (legacy) or options object with mode
  */
 export function useWorkouts(
   profileId: string | null,
-  daysBack: number = 7
+  daysBackOrOptions: number | UseWorkoutsOptions = 7
 ): {
   workouts: Workout[];
   isLoading: boolean;
   error: Error | null;
 } {
+  // Support both legacy daysBack number and new options object
+  const options: UseWorkoutsOptions = typeof daysBackOrOptions === 'number'
+    ? { mode: 'last7days' }
+    : daysBackOrOptions;
+  const mode = options.mode ?? 'last7days';
+
+  // For legacy daysBack support, extract the number
+  const daysBack = typeof daysBackOrOptions === 'number' ? daysBackOrOptions : 7;
+
   const { data, isLoading, error } = useQuery({
-    queryKey: [...WORKOUTS_KEY, profileId, daysBack],
+    queryKey: [...WORKOUTS_KEY, profileId, mode, daysBack],
     queryFn: async () => {
       if (!profileId) return [];
 
-      const endDate = new Date();
-      const startDate = new Date(getStartOfToday());
-      startDate.setDate(startDate.getDate() - daysBack + 1);
+      let startDate: Date;
+      let endDate: Date;
+
+      if (typeof daysBackOrOptions === 'number') {
+        // Legacy behavior: rolling daysBack window
+        endDate = new Date();
+        startDate = new Date(getStartOfToday());
+        startDate.setDate(startDate.getDate() - daysBackOrOptions + 1);
+      } else if (mode === 'last7days') {
+        endDate = getEndOfToday();
+        startDate = new Date(getStartOfToday());
+        startDate.setDate(startDate.getDate() - 6); // 6 days back + today = 7 days
+      } else {
+        // calendarWeek mode
+        startDate = getStartOfWeek();
+        endDate = new Date(startDate);
+        endDate.setDate(endDate.getDate() + 6); // Monday + 6 days = Sunday
+        endDate.setHours(23, 59, 59, 999);
+      }
 
       return db.workouts
         .where('profileId')
diff --git a/src/ui/components/MuscleHeatmap.tsx b/src/ui/components/MuscleHeatmap.tsx
index 7522d67..785addc 100644
--- a/src/ui/components/MuscleHeatmap.tsx
+++ b/src/ui/components/MuscleHeatmap.tsx
@@ -5,7 +5,7 @@
  */
 
 import React, { useMemo, useId } from 'react';
-import { useScientificMuscleVolume } from '@db/hooks/useVolumeStats';
+import { useScientificMuscleVolume, type ViewMode } from '@db/hooks/useVolumeStats';
 import type { ScientificMuscle } from '@core/taxonomy';
 import { getVolumeColor, getNoTargetColor } from '@core/color-scale';
 import Model from 'react-body-highlighter';
@@ -14,6 +14,7 @@ import type { IExerciseData, Muscle } from 'react-body-highlighter';
 interface MuscleHeatmapProps {
   profileId: string | null;
   daysBack?: number;
+  viewMode?: ViewMode;
 }
 
 /**
@@ -138,8 +139,10 @@ function getFrequencyLevel(percentage: number): number {
  * @param daysBack - Number of days to aggregate stats over (default: 7)
  * @returns A React element containing the split anterior/posterior muscle heatmap
  */
-export function MuscleHeatmap({ profileId, daysBack = 7 }: MuscleHeatmapProps): React.ReactElement {
-  const { stats, isLoading, error } = useScientificMuscleVolume(profileId, daysBack);
+export function MuscleHeatmap({ profileId, daysBack = 7, viewMode }: MuscleHeatmapProps): React.ReactElement {
+  // Use viewMode if provided, otherwise fall back to daysBack
+  const volumeArg = viewMode ?? daysBack;
+  const { stats, isLoading, error } = useScientificMuscleVolume(profileId, volumeArg);
 
   // Map stats to muscle-level data
   const muscleStats = useMemo((): MuscleStats[] => {
diff --git a/src/ui/components/TotalVolumeCard.tsx b/src/ui/components/TotalVolumeCard.tsx
index 88b21f5..20e3956 100644
--- a/src/ui/components/TotalVolumeCard.tsx
+++ b/src/ui/components/TotalVolumeCard.tsx
@@ -3,13 +3,18 @@
  * Shows total weekly volume with progress bar
  */
 
-import { useFunctionalGroupVolume } from '@db/hooks/useVolumeStats';
+import { useFunctionalGroupVolume, type ViewMode } from '@db/hooks/useVolumeStats';
 import { useCurrentProfile } from '../context/ProfileContext';
 
-export function TotalVolumeCard(): React.ReactElement {
+interface TotalVolumeCardProps {
+  viewMode?: ViewMode;
+}
+
+export function TotalVolumeCard({ viewMode = 'last7days' }: TotalVolumeCardProps): React.ReactElement {
   const { currentProfile } = useCurrentProfile();
   const { totalVolume, totalGoal, isLoading } = useFunctionalGroupVolume(
-    currentProfile?.id ?? null
+    currentProfile?.id ?? null,
+    viewMode
   );
 
   if (isLoading) {
diff --git a/src/ui/components/WeeklyActivityChart.tsx b/src/ui/components/WeeklyActivityChart.tsx
index a7e30b7..9c281c9 100644
--- a/src/ui/components/WeeklyActivityChart.tsx
+++ b/src/ui/components/WeeklyActivityChart.tsx
@@ -8,12 +8,14 @@ import { BarChart, Bar, XAxis, YAxis, ResponsiveContainer, Cell, Tooltip } from
 import { useDailyStats, type DailyActivity } from '../../db/hooks/useDailyStats';
 import { useCurrentProfile } from '../context/ProfileContext';
 
+type ViewMode = 'last7days' | 'calendarWeek';
+
 interface WeeklyActivityChartProps {
   profileId?: string;
+  viewMode?: ViewMode;
+  onViewModeChange?: (mode: ViewMode) => void;
 }
 
-type ViewMode = 'last7days' | 'calendarWeek';
-
 interface CustomTooltipProps {
   active?: boolean;
   payload?: Array<{ payload: DailyActivity }>;
@@ -153,11 +155,23 @@ function DayDetailPanel({ day, onClose }: DayDetailPanelProps): React.ReactEleme
  */
 export function WeeklyActivityChart({
   profileId: propProfileId,
+  viewMode: controlledViewMode,
+  onViewModeChange,
 }: WeeklyActivityChartProps): React.ReactElement {
   const { currentProfile } = useCurrentProfile();
   const profileId = propProfileId ?? currentProfile?.id ?? null;
 
-  const [viewMode, setViewMode] = useState<ViewMode>('last7days');
+  // Support both controlled and uncontrolled modes
+  const [internalViewMode, setInternalViewMode] = useState<ViewMode>('last7days');
+  const viewMode = controlledViewMode ?? internalViewMode;
+  const setViewMode = (mode: ViewMode): void => {
+    if (onViewModeChange) {
+      onViewModeChange(mode);
+    } else {
+      setInternalViewMode(mode);
+    }
+  };
+
   const [selectedDayIndex, setSelectedDayIndex] = useState<number | null>(null);
 
   const { days, isLoading, error } = useDailyStats(profileId, { mode: viewMode });
diff --git a/src/ui/components/mobile/MobileCarousel.tsx b/src/ui/components/mobile/MobileCarousel.tsx
index 0565cf9..4fe25aa 100644
--- a/src/ui/components/mobile/MobileCarousel.tsx
+++ b/src/ui/components/mobile/MobileCarousel.tsx
@@ -12,10 +12,12 @@ import { useState, useEffect, useCallback } from 'react';
 import useEmblaCarousel from 'embla-carousel-react';
 import { MobileHeatmap } from '@ui/components/mobile/MobileHeatmap';
 import { MobileMuscleList } from '@ui/components/mobile/MobileMuscleList';
+import type { ViewMode } from '@db/hooks/useWorkouts';
 
 interface MobileCarouselProps {
   profileId: string | null;
   daysBack?: number;
+  viewMode?: ViewMode;
 }
 
 /**
@@ -26,7 +28,8 @@ interface MobileCarouselProps {
  */
 export function MobileCarousel({
   profileId,
-  daysBack = 7
+  daysBack = 7,
+  viewMode,
 }: MobileCarouselProps): React.ReactElement {
   // Initialize Embla with critical options
   const [emblaRef, emblaApi] = useEmblaCarousel({
@@ -71,13 +74,14 @@ export function MobileCarousel({
             <MobileHeatmap
               profileId={profileId}
               daysBack={daysBack}
+              viewMode={viewMode}
               isActive={selectedIndex === 0}
             />
           </div>
 
           {/* Slide 2: Muscle List */}
           <div className="flex-[0_0_100%] min-w-0 px-4">
-            <MobileMuscleList profileId={profileId} daysBack={daysBack} />
+            <MobileMuscleList profileId={profileId} daysBack={daysBack} viewMode={viewMode} />
           </div>
         </div>
       </div>
diff --git a/src/ui/components/mobile/MobileHeatmap.tsx b/src/ui/components/mobile/MobileHeatmap.tsx
index dff22ef..468baf3 100644
--- a/src/ui/components/mobile/MobileHeatmap.tsx
+++ b/src/ui/components/mobile/MobileHeatmap.tsx
@@ -11,7 +11,7 @@
 import { useMemo, useId, useState, useCallback, useEffect } from 'react';
 import Model from 'react-body-highlighter';
 import type { IExerciseData, Muscle } from 'react-body-highlighter';
-import { useScientificMuscleVolume } from '@db/hooks';
+import { useScientificMuscleVolume, type ViewMode } from '@db/hooks';
 import { useEffectiveMuscleGroupConfig } from '@db/hooks/useMuscleGroups';
 import type { ScientificMuscle } from '@core/taxonomy';
 import { getVolumeColor, getNoTargetColor } from '@core/color-scale';
@@ -21,6 +21,7 @@ import { MuscleDetailModal } from './MuscleDetailModal';
 interface MobileHeatmapProps {
   profileId: string | null;
   daysBack?: number;
+  viewMode?: ViewMode;
   isActive?: boolean;
 }
 
@@ -134,9 +135,12 @@ interface MuscleStats {
 export function MobileHeatmap({
   profileId,
   daysBack = 7,
+  viewMode,
   isActive = true,
 }: MobileHeatmapProps): React.ReactElement {
-  const { stats, isLoading, error } = useScientificMuscleVolume(profileId, daysBack);
+  // Use viewMode if provided, otherwise fall back to daysBack
+  const volumeArg = viewMode ?? daysBack;
+  const { stats, isLoading, error } = useScientificMuscleVolume(profileId, volumeArg);
   const { config } = useEffectiveMuscleGroupConfig(profileId);
   const [view, setView] = useSessionState<'front' | 'back'>(
     'scientificmuscle_heatmap_view',
@@ -341,6 +345,7 @@ export function MobileHeatmap({
         relatedMuscles={selectedRegion ? REGION_TO_MUSCLES[selectedRegion].related : undefined}
         profileId={profileId}
         daysBack={daysBack}
+        viewMode={viewMode}
       />
     </div>
   );
diff --git a/src/ui/components/mobile/MobileMuscleList.tsx b/src/ui/components/mobile/MobileMuscleList.tsx
index e9f5718..2b77b79 100644
--- a/src/ui/components/mobile/MobileMuscleList.tsx
+++ b/src/ui/components/mobile/MobileMuscleList.tsx
@@ -15,7 +15,7 @@
  */
 
 import { useState, useMemo, useEffect } from 'react';
-import { useScientificMuscleVolume, type VolumeStatItem } from '@db/hooks/useVolumeStats';
+import { useScientificMuscleVolume, type VolumeStatItem, type ViewMode } from '@db/hooks/useVolumeStats';
 import { useEffectiveMuscleGroupConfig } from '@db/hooks/useMuscleGroups';
 import { getVolumeColor } from '@core/color-scale';
 import type { ScientificMuscle } from '@core/taxonomy';
@@ -23,6 +23,7 @@ import type { ScientificMuscle } from '@core/taxonomy';
 interface MobileMuscleListProps {
   profileId: string | null;
   daysBack?: number;
+  viewMode?: ViewMode;
 }
 
 /**
@@ -40,9 +41,12 @@ function formatVolume(volume: number): string {
 export function MobileMuscleList({
   profileId,
   daysBack = 7,
+  viewMode,
 }: MobileMuscleListProps): React.ReactElement {
   // Fetch volume data for all muscles
-  const { stats, isLoading: volumeLoading, error } = useScientificMuscleVolume(profileId, daysBack);
+  // Use viewMode if provided, otherwise fall back to daysBack
+  const volumeArg = viewMode ?? daysBack;
+  const { stats, isLoading: volumeLoading, error } = useScientificMuscleVolume(profileId, volumeArg);
 
   // Fetch custom group configuration
   const { config, isLoading: configLoading } = useEffectiveMuscleGroupConfig(profileId);
diff --git a/src/ui/components/mobile/MuscleDetailModal.tsx b/src/ui/components/mobile/MuscleDetailModal.tsx
index f7c389b..ad21308 100644
--- a/src/ui/components/mobile/MuscleDetailModal.tsx
+++ b/src/ui/components/mobile/MuscleDetailModal.tsx
@@ -15,7 +15,7 @@
 
 import { useEffect, useMemo, useState } from 'react';
 import { createPortal } from 'react-dom';
-import { useScientificMuscleVolume, type VolumeStatItem } from '@db/hooks/useVolumeStats';
+import { useScientificMuscleVolume, type VolumeStatItem, type ViewMode } from '@db/hooks/useVolumeStats';
 import { getVolumeColor } from '@core/color-scale';
 import type { ScientificMuscle } from '@core/taxonomy';
 import type { BodyRegion } from './MobileHeatmap';
@@ -32,6 +32,7 @@ interface MuscleDetailModalProps {
   // Common
   profileId: string | null;
   daysBack?: number;
+  viewMode?: ViewMode;
 }
 
 interface MuscleData {
@@ -107,11 +108,14 @@ export function MuscleDetailModal({
   muscle,
   profileId,
   daysBack = 7,
+  viewMode,
 }: MuscleDetailModalProps): React.ReactElement | null {
   // Determine mode: single muscle vs region
   const isSingleMuscleMode = muscle !== undefined && muscle !== null;
   // Fetch volume data for all muscles
-  const { stats } = useScientificMuscleVolume(profileId, daysBack);
+  // Use viewMode if provided, otherwise fall back to daysBack
+  const volumeArg = viewMode ?? daysBack;
+  const { stats } = useScientificMuscleVolume(profileId, volumeArg);
 
   // Create stats map for O(1) muscle lookup
   const statsMap = useMemo(() => {
diff --git a/src/ui/pages/Dashboard.tsx b/src/ui/pages/Dashboard.tsx
index 2f77c42..7ea3625 100644
--- a/src/ui/pages/Dashboard.tsx
+++ b/src/ui/pages/Dashboard.tsx
@@ -13,11 +13,14 @@ import { MobileCarousel } from '@ui/components/mobile/MobileCarousel';
 import { TotalVolumeCard } from '../components/TotalVolumeCard';
 import { WeeklyActivityChart } from '../components/WeeklyActivityChart';
 
+type ViewMode = 'last7days' | 'calendarWeek';
+
 export function Dashboard(): React.ReactElement {
   const { currentProfile, isLoading } = useCurrentProfile();
   const { count: unmappedCount } = useUnmappedExercises(currentProfile?.id ?? null);
   const isMobile = useIsMobileDevice();
   const [dismissedAlert, setDismissedAlert] = useState(false);
+  const [viewMode, setViewMode] = useState<ViewMode>('last7days');
 
   if (isLoading) {
     return (
@@ -78,22 +81,24 @@ export function Dashboard(): React.ReactElement {
       </div>
 
       {/* Total Weekly Volume */}
-      <TotalVolumeCard />
+      <TotalVolumeCard viewMode={viewMode} />
 
       {/* Weekly Activity Chart */}
-      <WeeklyActivityChart />
+      <WeeklyActivityChart viewMode={viewMode} onViewModeChange={setViewMode} />
 
-      {/* This Week Section */}
+      {/* Volume Display Section */}
       <div className="rounded-lg bg-primary-700 p-6">
         {isMobile ? (
-          <MobileCarousel profileId={currentProfile.id} />
+          <MobileCarousel profileId={currentProfile.id} viewMode={viewMode} />
         ) : (
           <>
             <div className="mb-6">
-              <h3 className="text-lg font-semibold text-white">This Week</h3>
+              <h3 className="text-lg font-semibold text-white">
+                {viewMode === 'calendarWeek' ? 'This Week' : 'Last 7 Days'}
+              </h3>
             </div>
 
-            <MuscleHeatmap profileId={currentProfile.id} />
+            <MuscleHeatmap profileId={currentProfile.id} viewMode={viewMode} />
           </>
         )}
       </div>