diff --git a/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometerTest.java b/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometerTest.java
index c3960161e..27466970d 100644
--- a/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometerTest.java
+++ b/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometerTest.java
@@ -24,7 +24,7 @@ public class AggregatorBarometerTest {
         addSensorValue(subject, new float[]{1015f, 1015.01f, 1015.02f, 1015.03f, 1015.04f, 1015.05f, 1015.06f, 1015.07f, 1015.08f, 1015.09f, 1015.10f, 1015.11f, 1015.12f, 1015.13f, 1018f, 1018.1f, 1018.1f, 1018.1f, 1018.1f});
 
         // then
-        Assert.assertEquals(0f, subject.aggregatedValue.gain_m(), 0.01);
-        Assert.assertEquals(15f, subject.aggregatedValue.loss_m(), 0.01);
+        Assert.assertEquals(0f, subject.output.gain_m(), 0.01);
+        Assert.assertEquals(15f, subject.output.loss_m(), 0.01);
     }
 }
\ No newline at end of file
diff --git a/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/SensorDataCyclingTest.java b/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/SensorDataCyclingTest.java
index 51b41cd15..f7f06e13e 100644
--- a/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/SensorDataCyclingTest.java
+++ b/src/androidTest/java/de/dennisguse/opentracks/sensors/sensorData/SensorDataCyclingTest.java
@@ -2,6 +2,7 @@ package de.dennisguse.opentracks.sensors.sensorData;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 
@@ -12,7 +13,6 @@ import java.time.Instant;
 
 import de.dennisguse.opentracks.data.models.Cadence;
 import de.dennisguse.opentracks.data.models.Distance;
-import de.dennisguse.opentracks.data.models.Speed;
 import de.dennisguse.opentracks.sensors.UintUtils;
 import de.dennisguse.opentracks.sensors.driver.CyclingCadenceBluetooth;
 import de.dennisguse.opentracks.sensors.driver.CyclingDistanceSpeedBluetooth;
@@ -93,7 +93,7 @@ public class SensorDataCyclingTest {
         // then
         // TODO See #953
 //        assertEquals(60, current.getValue().getRPM(), 0.01);
-        assertEquals(Cadence.of(0), current.getAggregatedValue(Instant.MIN));
+        assertNull(current.getAggregatedValue(Instant.MIN));
     }
 
     @Test
@@ -120,11 +120,10 @@ public class SensorDataCyclingTest {
         current.add(Instant.MIN, new CyclingDistanceSpeedBluetooth.WheelData(UintUtils.UINT32_MAX - 1, 1024));
         current.add(Instant.MIN, new CyclingDistanceSpeedBluetooth.WheelData(0, 2048));
 
-
         // then
         // TODO See #953
 //        assertEquals(2, current.getValue().getDistance().toM(), 0.01);
 //        assertEquals(2, current.getValue().getSpeed().toMPS(), 0.01);
-        assertEquals(new AggregatorCyclingDistanceSpeed.Data(Distance.ZERO, Distance.ZERO, Speed.ZERO), current.getAggregatedValue(Instant.MIN));
+        assertNull(current.getAggregatedValue(Instant.MIN));
     }
 }
\ No newline at end of file
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java
index d61cd8a5a..0cec85cc3 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java
@@ -1,17 +1,20 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import java.time.Duration;
 import java.time.Instant;
 
-public abstract class Aggregator<Input, Output> {
+public abstract class Aggregator<InputType, OutputType> {
 
     private static final Duration MAX_SENSOR_DATE_SET_AGE = Duration.ofSeconds(5);
 
-    protected Raw<Input> previous;
+    @Nullable
+    protected Raw<InputType> previous;
 
-    protected Output aggregatedValue;
+    //TODO Make private
+    protected OutputType output;
 
     private final String sensorAddress;
     private final String sensorName;
@@ -25,57 +28,47 @@ public abstract class Aggregator<Input, Output> {
         return sensorName != null ? sensorName : sensorAddress;
     }
 
-    public final void add(Instant now, Input current) {
-        Raw<Input> next = new Raw<>(now, current);
+    public final void add(Instant now, InputType current) {
+        Raw<InputType> next = new Raw<>(now, current);
         computeValue(next);
         previous = next;
     }
 
-    protected abstract void computeValue(Raw<Input> current);
+    protected abstract void computeValue(Raw<InputType> current);
 
     /**
      * @return did we process data from a sensor.
      * NOTE: for some sensors this may require more than one measurement.
      */
     public boolean hasReceivedData() {
-        return aggregatedValue != null;
+        return output != null;
     }
 
-    @Deprecated //TODO Remove: for sensor there is no default value. Make getAggregatedValue() @Nullable
-    @NonNull
-    protected abstract Output getNoneValue();
-
-    @Deprecated //TODO Removed; just implemented for refactoring. This code is bypassing core functionality of this class.
-    public Output getAggregatedValue() {
-        return aggregatedValue;
-    }
-
-    @NonNull
-    public Output getAggregatedValue(Instant now) {
-        if (!hasReceivedData()) {
-            return getNoneValue();
-        }
+    @Nullable
+    protected OutputType getAggregatedValue(Instant now) {
         if (isOutdated(now)) {
-            resetImmediate();
+            resetOutdated();
         }
 
-        return aggregatedValue;
+        return output;
     }
 
     @NonNull
-    public SensorData<Output> getAggregatedValueWithSensorName(Instant now) {
+    public SensorData<OutputType> getAggregatedValueWithSensorName(Instant now) {
         return new SensorData<>(getAggregatedValue(now), getSensorNameOrAddress());
     }
 
     /**
      * Reset short-term (i.e., non-aggregated) values that were directly derived from sensor data.
      */
-    protected abstract void resetImmediate();
+    protected void resetOutdated() {
+        output = null;
+    };
 
     /**
      * Reset long-term (i.e., aggregated) values (more than derived from previous SensorData) like overall distance.
      */
-    public abstract void resetAggregated();
+    public void resetAggregated() {};
 
     /**
      * Is the data recent considering the current time.
@@ -99,7 +92,7 @@ public abstract class Aggregator<Input, Output> {
     @NonNull
     @Override
     public String toString() {
-        return "sensorAddress=" + sensorAddress + " data=" + aggregatedValue;
+        return "sensorAddress=" + sensorAddress + " data=" + output;
     }
 
     protected record Raw<T>(
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java
index bd6b1b017..c5b9be679 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java
@@ -1,7 +1,5 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
-import androidx.annotation.NonNull;
-
 import de.dennisguse.opentracks.data.models.Altitude;
 import de.dennisguse.opentracks.data.models.AltitudeGainLoss;
 import de.dennisguse.opentracks.data.models.AtmosphericPressure;
@@ -19,31 +17,28 @@ public class AggregatorBarometer extends Aggregator<AtmosphericPressure, Altitud
     protected void computeValue(Raw<AtmosphericPressure> current) {
         if (previous == null) {
             lastAcceptedSensorValue = current.value();
-            aggregatedValue = getNoneValue();
+            output = new AltitudeGainLoss(0f, 0f);
             return;
         }
 
         PressureSensorUtils.AltitudeChange altitudeChange = PressureSensorUtils.computeChangesWithSmoothing_m(lastAcceptedSensorValue, previous.value(), current.value());
         if (altitudeChange != null) {
-            aggregatedValue = new AltitudeGainLoss(aggregatedValue.gain_m() + altitudeChange.getAltitudeGain_m(), aggregatedValue.loss_m() + altitudeChange.getAltitudeLoss_m());
+            if (output == null) {
+                output = new AltitudeGainLoss(0f, 0f);
+            }
+            output = new AltitudeGainLoss(output.gain_m() + altitudeChange.getAltitudeGain_m(), output.loss_m() + altitudeChange.getAltitudeLoss_m());
 
             lastAcceptedSensorValue = altitudeChange.currentSensorValue();
         }
     }
 
     @Override
-    protected void resetImmediate() {
+    protected void resetOutdated() {
     }
 
     @Override
     public void resetAggregated() {
-        aggregatedValue = getNoneValue();
-    }
-
-    @NonNull
-    @Override
-    protected AltitudeGainLoss getNoneValue() {
-        return new AltitudeGainLoss(0f, 0f);
+        output = null;
     }
 
     public record Data(Altitude gain, Altitude loss) {}
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java
index 6f109d8e9..7cb7c21fa 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java
@@ -2,8 +2,6 @@ package de.dennisguse.opentracks.sensors.sensorData;
 
 import android.util.Log;
 
-import androidx.annotation.NonNull;
-
 import java.time.Duration;
 
 import de.dennisguse.opentracks.data.models.Cadence;
@@ -32,32 +30,18 @@ public class AggregatorCyclingCadence extends Aggregator<CyclingCadenceBluetooth
         }
         if (timeDiff.isNegative()) {
             Log.e(TAG, "Timestamps difference is invalid: cannot compute cadence.");
-            aggregatedValue = null;
+            output = null;
             return;
         }
 
         // TODO We have to treat with overflow according to the documentation: read https://codeberg.org/OpenTracksApp/OpenTracks/pulls/953#issuecomment-6466930
         if (current.value().crankRevolutionsCount() < previous.value().crankRevolutionsCount()) {
             Log.e(TAG, "Crank revolutions count difference is invalid: cannot compute cadence.");
+            output = null;
             return;
         }
 
         long crankDiff = UintUtils.diff(current.value().crankRevolutionsCount(), previous.value().crankRevolutionsCount(), UintUtils.UINT32_MAX);
-        aggregatedValue = Cadence.of(crankDiff, timeDiff);
-    }
-
-    @Override
-    protected void resetImmediate() {
-        aggregatedValue = getNoneValue();
-    }
-
-    @Override
-    public void resetAggregated() {
-    }
-
-    @NonNull
-    @Override
-    protected Cadence getNoneValue() {
-        return Cadence.of(0);
+        output = Cadence.of(crankDiff, timeDiff);
     }
 }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java
index 4d1a273ca..c3207904f 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java
@@ -2,8 +2,6 @@ package de.dennisguse.opentracks.sensors.sensorData;
 
 import android.util.Log;
 
-import androidx.annotation.NonNull;
-
 import java.time.Duration;
 
 import de.dennisguse.opentracks.data.models.Distance;
@@ -35,43 +33,39 @@ public class AggregatorCyclingDistanceSpeed extends Aggregator<CyclingDistanceSp
         }
         if (timeDiff.isNegative()) {
             Log.e(TAG, "Timestamps difference is invalid: cannot compute cadence.");
-            aggregatedValue = null;
+            output = null;
             return;
         }
 
         if (current.value().wheelRevolutionsCount() < previous.value().wheelRevolutionsCount()) {
             Log.e(TAG, "Wheel revolutions count difference is invalid: cannot compute speed.");
+            output = null;
             return;
         }
         long wheelDiff = UintUtils.diff(current.value().wheelRevolutionsCount(), previous.value().wheelRevolutionsCount(), UintUtils.UINT32_MAX);
 
         Distance distance = wheelCircumference.multipliedBy(wheelDiff);
         Distance distanceOverall = distance;
-        if (aggregatedValue != null) {
-            distanceOverall = distance.plus(aggregatedValue.distanceOverall);
+        if (output != null) {
+            distanceOverall = distance.plus(output.distanceOverall);
         }
         Speed speed_mps = Speed.of(distance, timeDiff);
-        aggregatedValue = new Data(distance, distanceOverall, speed_mps);
+        output = new Data(distance, distanceOverall, speed_mps);
     }
 
     @Override
-    protected void resetImmediate() {
-        aggregatedValue = new Data(Distance.ZERO, aggregatedValue.distanceOverall, Speed.ZERO);
+    protected void resetOutdated() {
+        Distance overallDistance = output != null ? output.distanceOverall : Distance.ZERO;
+        output = new Data(Distance.ZERO, overallDistance, Speed.ZERO);
     }
 
     @Override
     public void resetAggregated() {
-        if (aggregatedValue != null) {
-            aggregatedValue = new Data(aggregatedValue.distance, Distance.ZERO, aggregatedValue.speed);
+        if (output != null) {
+            output = new Data(output.distance, Distance.ZERO, output.speed);
         }
     }
 
-    @NonNull
-    @Override
-    protected Data getNoneValue() {
-        return new Data(Distance.ZERO, Distance.ZERO, Speed.ZERO);
-    }
-
     public void setWheelCircumference(Distance wheelCircumference) {
         this.wheelCircumference = wheelCircumference;
     }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java
index a369763a8..69fa67b16 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java
@@ -1,7 +1,5 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
-import androidx.annotation.NonNull;
-
 import de.dennisguse.opentracks.data.models.Power;
 import de.dennisguse.opentracks.sensors.driver.CyclingPowerBluetooth;
 
@@ -13,21 +11,6 @@ public class AggregatorCyclingPower extends Aggregator<CyclingPowerBluetooth.Dat
 
     @Override
     public void computeValue(Raw<CyclingPowerBluetooth.Data> current) {
-        this.aggregatedValue = current.value().power();
-    }
-
-    @Override
-    protected void resetImmediate() {
-        aggregatedValue = getNoneValue();
-    }
-
-    @Override
-    public void resetAggregated() {
-    }
-
-    @NonNull
-    @Override
-    protected Power getNoneValue() {
-        return Power.of(0f);
+        this.output = current.value().power();
     }
 }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java
index af6731b86..f57f3bbfb 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java
@@ -10,19 +10,13 @@ import de.dennisguse.opentracks.data.models.Position;
 
 public class AggregatorGPS extends Aggregator<Location, Position> {
 
-
     public AggregatorGPS(String sensorAddress, String sensorName) {
         super(sensorAddress, sensorName);
     }
 
     @Override
     protected void computeValue(Raw<Location> current) {
-        aggregatedValue = Position.of(current.value(), current.time());
-    }
-
-    @Override
-    protected void resetImmediate() {
-        aggregatedValue = Position.empty();
+        output = Position.of(current.value(), current.time());
     }
 
     @Override
@@ -32,19 +26,15 @@ public class AggregatorGPS extends Aggregator<Location, Position> {
          * The data is too large to save it more often than needed (i.e., duplicated values).
          * TODO: this behavior can be changed if TrackRecordingManager.insertTrackPoint() would strip GPS data if it was already saved. This would simplify TrackPointCreator.createCurrentTrackPoint()
          */
-        aggregatedValue = Position.empty();
-    }
-
-    @NonNull
-    @Override
-    protected Position getNoneValue() {
-        return Position.empty();
+        output = null;
     }
 
     @NonNull
     @Override
     public Position getAggregatedValue(Instant now) {
-        return super.getAggregatedValue(now)
-                .with(now);
+        Position value = super.getAggregatedValue(now);
+        if (value == null) value = Position.empty();
+
+        return value.with(now);
     }
 }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java
index 22c7bea24..b7bc6ad9d 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java
@@ -1,7 +1,5 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
-import androidx.annotation.NonNull;
-
 import de.dennisguse.opentracks.data.models.HeartRate;
 
 public class AggregatorHeartRate extends Aggregator<HeartRate, HeartRate> {
@@ -13,22 +11,7 @@ public class AggregatorHeartRate extends Aggregator<HeartRate, HeartRate> {
     @Override
     protected void computeValue(Raw<HeartRate> current) {
         if (current.value().isValid()) {
-            this.aggregatedValue = current.value();
+            this.output = current.value();
         }
     }
-
-    @Override
-    protected void resetImmediate() {
-        aggregatedValue = getNoneValue();
-    }
-
-    @Override
-    public void resetAggregated() {
-    }
-
-    @NonNull
-    @Override
-    protected HeartRate getNoneValue() {
-        return HeartRate.of(0);
-    }
 }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java
index 8cdf81b93..a5c7bc34e 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java
@@ -27,33 +27,31 @@ public final class AggregatorRunning extends Aggregator<RunningSpeedAndCadenceBl
         Distance distance = null;
         if (previous.value().totalDistance() != null && current.value().totalDistance() != null) {
             distance = current.value().totalDistance().minus(previous.value().totalDistance());
-            if (aggregatedValue != null) {
-                distance = distance.plus(aggregatedValue.distance);
+            if (output != null) {
+                distance = distance.plus(output.distance);
             }
         }
 
-        aggregatedValue = new Data(current.value().speed(), current.value().cadence(), distance);
+        output = new Data(current.value().speed(), current.value().cadence(), distance);
     }
 
     @Override
-    protected void resetImmediate() {
-        aggregatedValue = new Data(Speed.ZERO, Cadence.of(0f), aggregatedValue.distance);
+    protected void resetOutdated() {
+        Distance distance = output != null ? output.distance : Distance.ZERO;
+        output = new Data(Speed.ZERO, Cadence.of(0f), distance);
     }
 
     @Override
     public void resetAggregated() {
-        if (aggregatedValue != null) {
-            aggregatedValue = new Data(aggregatedValue.speed, aggregatedValue.cadence, Distance.ZERO);
+        if (output != null) {
+            output = new Data(output.speed, output.cadence, Distance.ZERO);
         }
     }
 
-    @NonNull
-    @Override
-    protected Data getNoneValue() {
-        return new Data(Speed.ZERO, Cadence.of(0f), Distance.ZERO);
-    }
-
-    public record Data(Speed speed, Cadence cadence, @NonNull Distance distance) {
+    public record Data(
+            Speed speed,
+            Cadence cadence,
+            @NonNull Distance distance) {
     }
 }
 
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java
index 18609ff01..0355a71ce 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java
@@ -1,7 +1,5 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
-import androidx.annotation.NonNull;
-
 import java.time.Duration;
 
 import de.dennisguse.opentracks.data.models.Temperature;
@@ -13,20 +11,9 @@ public class AggregatorTemperature extends Aggregator<Temperature, Temperature>
     }
 
     protected void computeValue(Raw<Temperature> current) {
-        this.aggregatedValue = current.value();
+        this.output = current.value();
     }
 
-    @NonNull
-    protected Temperature getNoneValue() {
-        return Temperature.ofCentiCelsius(0);
-    }
-
-    protected void resetImmediate() {
-        aggregatedValue = getNoneValue();
-    }
-
-    public void resetAggregated() {};
-
     @Override
     protected Duration getMaxSensorAge() {
         return Duration.ofMinutes(1);
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/SensorData.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/SensorData.java
index 104bf718a..7758b02f1 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/SensorData.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/SensorData.java
@@ -1,7 +1,11 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
+import androidx.annotation.Nullable;
+
 public record SensorData<T>(
 
+
+        @Nullable
         T data,
 
         String sensorNameOrAddress