Biology Common Questions

We’ve compiled answers to the most frequently asked questions about Biology.

Bevel gets your body data from Apple Health or connected integrations.

• Weight can be logged directly in Bevel, or synced from Apple Health or a connected device.

• Lean Body Mass and Body Fat can’t be entered directly in Bevel. They are imported from Apple Health or other integrations. Smart scales can capture this data and sync it to Apple Health.

To verify if you have Cardio Fitness or VO₂ Max data, go to Apple Health → VO₂ Max (Cardio Fitness) and check if any data is recorded. If your device does not sync to Apple Health, check your connected device or integration to confirm it is tracking and syncing this data.

On Apple Watch, VO₂ Max is estimated during outdoor walks, runs, and hikes. Each workout should be at least ~20 minutes so the watch can gather enough data. Because the estimate uses GPS distance, these workouts need to be done outdoors. Garmin devices can also estimate VO₂ Max during cycling when power (watts) data is available.

Tip: In Bevel, you can manage what data sources VO₂ Max data comes from by going to Profile → Data Sources → VO₂ Max. You can read more about managing data sources here.

If you have a mix of physiological, lifestyle, and blood biomarkers available, you may notice that the year-impact estimates across your individual factors don't add up neatly to your total Biological Age delta. This is intentional.

Many factors in the model overlap; they're measuring related aspects of the same underlying biology. Resting Heart Rate and VO₂ Max both reflect cardiovascular fitness. Glucose and Nutrition Score are biologically linked. Lean Body Mass and Strength Training are cause and effect. If the model treated each independently, it would double-count these relationships and overstate the total impact. Instead, Bevel accounts for this, so the combined effect is appropriately moderated. The individual contributions won't sum to a clean total, but the overall estimate is more accurate because of it.

In addition, Biological Age takes into account the Confidence Level for each biomarker, and prioritizes those with the most up to date and complete data. For example, if your blood tests are 18 months old, they will be weighted less in the overall Biological Age equation.

The PhenoAge formula weights each Blood Biomarker by its impact on the result. If a high-weight Biomarker like RDW or MCV is missing, the result would be too inaccurate to show, so Bevel omits blood age entirely rather than display a misleading number. Lower-weight Biomarkers like hs-CRP and ALP can be absent without affecting the result enough to matter.

The blood-based portion of Biological Age uses the published PhenoAge formula, which is based on specific blood biomarkers. You can learn more about the biomarkers and methodology here.

One limitation of the formula is that it does not account for factors such as:

• High levels of physical training

• Increased muscle mass

• Creatine supplementation

People who exercise frequently or take creatine may have elevated creatinine levels, which can influence the calculation and make Blood Biological Age appear higher than expected. Unfortunately, this is a limitation of the published formula itself rather than an issue specific to Bevel.

Biological Age calculations are based on the past 4 weeks of biomarker data associated with your results, not just the upload date.

• If you upload bloodwork today that was originally taken weeks or months ago, it may be reflected automatically because it falls within the timeframe already used in your current Biological Age calculation.

• However, if your bloodwork was taken this week, it will generally be included in the next scheduled Biological Age update, which occurs on Monday.

For example, if your current Biological Age was calculated on May 11 using data from April 11–May 11, bloodwork uploaded today but taken on May 1 may update immediately, while bloodwork taken today would instead be included in the next update on May 18.