What are cardio load and target load?

Cardio load measures the strain on your cardiovascular system during exercise and daily activities. It considers not only the duration but also the intensity of your efforts, which recognizes that higher-intensity exercise places greater demands on your heart. You receive more cardio load for longer or more strenuous activity based on your heart rate.

Your target load is a suggested cardio load range that you can use to guide your training. Aim to get enough cardio load so that it lands in the target load range each day. It takes into account your fitness level, recent activity, and how recovered your body is. It also considers whether you plan to maintain or improve your cardio fitness level. Think of it as a "sweet spot" for exercise.

• Track Your Progress: Track your cardio load over time to monitor your progress toward your fitness goals.
• Optimize Your Training: Use cardio load to guide daily activity levels and intensity. This ensures that you work out at the right intensity to reach your goals, while you consider your recovery.
• Balance your Training Load: Use your results to help you understand if you have accumulated the right amount of cardio load for the goal you’ve set for yourself. You can use the result to decide if you want to maintain or improve your cardio fitness.

Additional Tips

• Individualized Metric: Remember that cardio load is personalized to you, based on your heart rate during physical activity. This helps ensure your daily target load is still achievable with the right amount of challenge. You can also get additional information and recommendations here:
  • Training status: It shows how well you’re training recently. You get notified whether you’re Under training, Improving fitness, or Over training. This can help you decide if you want to adjust your next workout or training sessions.

  • Workout recommendations: It recommends a specific workout with details like duration, distance, and difficulty. It also shows the estimated cardio load after you complete the workout so you can stay on top of your daily target.

• Varied Activities: Cardio load can be accumulated through activities that increase your heart rate. This includes including running, cycling, swimming, walking, and any of the 40+ activities in Fitbit device.
• Consult with Professionals: If you have concerns about your heart health or training intensity, you should always consult with a healthcare professional or certified trainer.

Cardio load is based on the TRIMP (TRaining IMPulse) model, a well-established method to assess your training load. This model takes into account your heart rate during activity, and factors like your age, resting heart rate, and sex.

Fitbit uses several factors to calculate your target load:

• Training Target: Your target load is tailored to the fitness target you have set in the Fitbit app to maintain or improve fitness. Select "maintain cardio fitness" to adjust your target cardio load to be in line with your average cardio load over the last 4 weeks. Select "improve cardio fitness" to adjust your target cardio load to be slightly more than your daily average over the last 4 weeks.
• Recent activity: Fitbit compares the last week of cardio load with the last month (often called Acute to Chronic Workload Ratio or ACWR). This ensures that your target load is appropriate for your current level of training. If you’ve had a lighter last few days of activity, your target load might be higher while if you’ve taken on more recently, it might be lower. This helps you maintain balance and prevent over training.

Target load needs time to calibrate to you and your activity. Your first target load score appears after 7 consecutive days and nights of wearing the watch.

You start every day with zero cardio load. As your heart rate increases to the light zone and beyond, you'll begin to accumulate cardio load. At midnight, your cardio load resets to zero. There is no practical maximum to the load you can accumulate each day.

The maximum load represented by the end of the cardio load arc in the Fitbit app or on your watch is personalized based on your highest days of cardio load from the past 28 days. As you reach new maximum cardio load levels, you’ll notice this adjust as a result.

Target Load is best for people who regularly train their cardiovascular system, ideally in a consistent pattern of days.

You can achieve your target load by performing physical activities that earn cardio load. These are any activities that raise your heart rate into or above the "light" intensity zone (a personalized zone based on your fitness level and other factors). The more intense your activity, the faster you accrue cardio load and the sooner you reach your target load. Remember that your target load is for the whole day, and not just for a dedicated workout.

• Daily Goal: Aim to accumulate enough cardio load throughout the day to fall within your target load at the end of the day.
• Visual Guide: The Today section in the Fitbit app and watch displays your daily progress toward your target load goal to help you stay on track.
• Adjustments: Your target load may change over time as your fitness improves or if your activity levels change.

Fitbit measures how active you’ve been over the last 7 days in comparison to how active you've been in the last 4 weeks to determine your training status.

If you take on too much cardio load too quickly, you’re at risk of over training. When you're over trained, your body constantly fights to recover. Instead of improving your endurance and stamina, over training can lower your cardiovascular performance. You might find it harder to maintain your usual pace or distance, and you might feel more easily fatigued.

Conversely, if you stop training for a period of time, you’re at risk of under training. While taking breaks is essential, long periods of inactivity can reverse the gains you've made in your cardiovascular fitness. Your heart and lungs become less efficient at delivering oxygen to your muscles. You may notice that you tire more easily and can't sustain your previous levels of exercise intensity or duration.

The sweet spots between under training and over training are maintaining or improving. Maintaining means you’re getting a consistent amount of cardio load and you regularly reach your target range. Improving indicates you’re regularly reaching the top of your target range or slightly exceeding it, helping improve your fitness.

Your target load guides you to maintain or improve depending on what goal you choose when you onboard. To change your goal:

1. From the Today tab in the Fitbit app, tap the Cardio load tile.
2. Tap Adjust my target under the Fitness target section.
3. Choose Improve cardio fitness or Maintain cardio fitness to select your goal.

• Just-right Training: Your target load takes your current fitness level and recent activity patterns into account. Hitting your target load consistently can help you achieve your fitness goals safely and effectively.
• Injury Prevention: Staying within your target load range can help to prevent over training, reducing the risk of injuries and burnout.
• Motivation: Tracking your progress toward your target load can be a great motivator to keep you engaged and excited about your workouts.

Remember: Target load isn't a rigid rule, but a helpful guide based on your body. Listen to your body, prioritize rest when needed, and enjoy the journey to a healthier, fitter you.

General Considerations:

• Ensure you allow sufficient time for your watch calibration for each individual activity levels, establishing a baseline measurement.
• Certain medications affecting heart rate will influence cardio load and target load calculations.
• Infrequent or erratic training patterns can impede accurate target load calculation.

If the target load appears low:

• Check your recovery levels a lower level may require a target load adjustment.
• The actual daily cardio load is the amount of stress placed on the cardiovascular system during physical activity. An individual’s perceived exertion may be different from the actual exertion. This discrepancy can arise from various factors, which include individual fitness levels, exercise intensity, duration, and environmental conditions.

If the target load appears high:

• Target load is derived from your daily cardio loads accumulated over several days. Daily cardio load accrues throughout daily activities like running, cycling, swimming, walking, and any of the 40+ activities in Fitbit, not solely during workouts. Thus, the target load encompasses the entire daily target, not a singular workout.
• Prioritize self-assessment. If readiness is high but you feel fatigued, listen to your body and take it break.
• This may indicate early stages of illness, not yet reflected in the readiness score, and may influence target load. Prioritize rest, taking breaks, and reducing the intensity of your workout.

Cardio load is available in the Fitbit mobile app when you use one of these devices:

From the Today tab or Fitness tab Fitness icon in the Fitbit app, tap the Cardio load tile. Follow the instructions in the app to choose your goal and begin tracking cardio load. After you wear your device for two weeks, your cardio load goal becomes a personalized cardio load target. This is automatically determined based on your average cardio load in the previous two weeks.

This brings flexibility to your workout routines:

• Hit the sweet spot in your training: Your personalized target can help you keep up with your fitness goals without under training or over training.
• Choose how hard you want to push: You can choose to just hit your target to maintain your current fitness level or push forward for more gains.
• Your target adjusts to your fitness level: Each week, Fitbit adjusts your target based on your cardio load average from the past few weeks.

[Optional] To set cardio load as your focus at the top of the Today tab:

1. From the Today tab in the Fitbit app, tap Edit Google Translate Pencil Icon.
2. Under Set your focus, swipe through the options and select Build cardio fitness.
3. Tap Save.

Tip: Target load needs time to calibrate to you. Your first target load range appears after 7 consecutive days of accumulating cardio load and sleeping with your device. To get the most accurate target, wear your watch during the daytime, especially during periods of exercise. For best results wear continuously for 28 days.

1. From the Today tab in the Fitbit app, tap the Cardio load tile.
2. Tap the menu icon and then Manage data.
3. Tap Delete Data and then Cardio load.
4. Select the data range you want to delete.
5. Tap Delete.

1. From your watch face, swipe to any tile.
2. Long press on the tile to bring up the tile selector menu.
3. Tap Add to add a tile.
4. Scroll vertically to find the Cardio Load tile and tap to select it.
5. Use the arrows to select where the tile should appear among the other tiles on your watch.
6. Press the crown to return to your watch face.

1. From your watch face, swipe left or right until you reach the Cardio Load tile.
2. Long press on the tile to bring up the tile selector menu.
3. Swipe vertically from bottom to top to remove the tile.
4. Press the crown to return to your watch face.¹