Time in target: healthy range and what your number means

What is Time in target?

Time in target is the percentage of time (over a defined period like a day or week) that your CGM glucose readings fall within a specified “ideal” zone. In Vively’s model, this zone is 4.0 to 6.0 mmol/L, capturing your “metabolic sweet spot.”

Why does it matter for long-term health and wellbeing?

Because glucose variability and excursions (above or below target) are tied to metabolic stress, oxidative load, and signalling disturbances. The more stable your glucose within an ideal window, the less frequent those stresses. Over time this supports better energy, insulin sensitivity and resilience, which all feed into long-term metabolic fitness.

What’s an optimal level of Time in target? (show optimal and lab ranges)

Vively frames 100 % as ideal, meaning that nearly all of your monitored time is within 4 to 6 mmol/L. But in practice, people starting out will spend significant time outside that zone. A reference tier system might look like:

• 20 %: 91 to 120 minutes out of target
• 40 %: 61 to 90 minutes out
• 60 %: 31 to 60 minutes out
• 80 %: 1 to 30 minutes out
• 100 %: fully in range

These tiers help you see progress. Traditional clinical labs or CGM consensus ranges (e.g. 3.9 to 10.0 mmol/L) are much broader, but for optimal metabolic health, the tighter band gives more actionable precision.

What influences Time in target levels?

Many lifestyle and physiological factors, including:

• Meal composition, timing and glycaemic load
• Glycaemic response to fats, protein, fibre
• Exercise intensity and recovery
• Sleep quality and circadian alignment
• Stress, hormonal fluxes and autonomic tone
• Baseline insulin sensitivity, intra-individual variation
• Timing of food or activity relative to monitoring window

What does it mean if Time in target is outside the optimal range?

If your time in target is low, it suggests your glucose is frequently drifting above or below your metabolic window. That means more frequent excursions, which act as small internal stresses. But it also gives early, actionable insight, not a medical diagnosis, but a cue to experiment with your meals, activity or sleep timing. Over time, small improvements compound.

How can I support healthy Time in target levels?

• Prioritise meals with low to moderate glycaemic load, plenty of fibre and protein
• Distribute carbs sensibly (e.g. avoid big glycaemic “spikes”)
• Use physical activity (especially post-meal walking or light movement)
• Optimise sleep duration and consistency
• Reduce stress and support recovery (e.g. breathing, rest)
• Monitor and iterate: review your CGM graph daily/weekly, test tweaks, and adjust

This information is provided for general health and wellness purposes only and does not replace medical advice.

References

1. Battelino, T., et al. (2019). Clinical Targets for Continuous Glucose Monitoring Data: Recommendations From the International Consensus. Diabetes Care, 42(8).
2. Hill, N. R., et al. (2019). Defining Continuous Glucose Monitor Time in Range in a Large Population of Individuals Without Diabetes. The Journal of Clinical Endocrinology & Metabolism.
3. Moser, O., et al. (2020). Time in range: a new parameter to evaluate blood glucose control in diabetes. Diabetology & Metabolic Syndrome.
4. Stevens, J., et al. (2024). Continuous Glucose Monitors and Programmed Shared Decision Support in Metabolic Health. SAGE Journals.