Research
The research behind Fortiv.
Last updated September 10, 2026
Fortiv’s coaching recommendations are grounded in published research. Each item below is a claim the app makes, and the study or guideline it’s based on.
Recovery lagging behind training load
Why Fortiv surfaces an Ease Up state when your recovery trend drops while training load holds steady.
Plews, D.J. et al. (2013). "Training Adaptation and Heart Rate Variability in Elite Endurance Athletes: Opening the Door to Effective Monitoring." Sports Medicine.
View source (Sports Medicine) →Planned deload / lighter training weeks
Why Fortiv builds in scheduled lighter weeks instead of pushing continuous progressive overload.
Kraemer, W.J. et al. (2002). "Progression Models in Resistance Training for Healthy Adults." ACSM Position Stand, Medicine & Science in Sports & Exercise.
View source (PubMed) →Rapid weight-loss rate and muscle preservation
Why Fortiv caps recommended weekly weight-loss rate rather than maximizing deficit speed.
Garthe, I. et al. (2011). "Effect of Two Different Weight-Loss Rates on Body Composition and Strength and Power-Related Performance in Elite Athletes." International Journal of Sport Nutrition and Exercise Metabolism.
View source (PubMed) →Zone 2 training and aerobic benefit
Why Fortiv tracks weekly zone 2 minutes as a distinct metric from workout completion.
Achten, J., Gleeson, M., & Jeukendrup, A.E. (2002). "Determination of the Exercise Intensity that Elicits Maximal Fat Oxidation." Medicine & Science in Sports & Exercise, 34(1), 92–97.
View source (PubMed) →150 min/week cardio guideline
The baseline Fortiv uses for a sustainable weekly cardio target.
American Heart Association. Recommendations for Physical Activity in Adults.
View source (American Heart Association) →Weigh-in / logging consistency
Why Fortiv nudges consistent logging rather than treating a single weigh-in as a checkpoint.
Burke, L.E. et al. (2011). "Self-Monitoring in Weight Loss: A Systematic Review of the Literature." Journal of the American Dietetic Association.
View source (PMC) →Recovering after a missed week
Why Fortiv treats a missed week as a normal input to regroup from, not a reset of progress.
Rodrigues, F. et al. (2020). "Understanding Exercise Adherence: The Predictability of Past Experience and Motivational Determinants." Brain Sciences.
View source (PMC) →Protein target
The basis for the daily protein range Fortiv recommends.
Bauer, J. et al. (2013). "Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People: A Position Paper from the PROT-AGE Study Group." Journal of the American Medical Directors Association.
View source (PubMed) →Losing fat while holding or gaining muscle (body recomposition)
Why Fortiv sets higher protein targets during a cutting phase paired with resistance training.
Longland, T.M. et al. (2016). "Higher Compared with Lower Dietary Protein During an Energy Deficit Combined with Intense Exercise Promotes Greater Lean Mass Gain and Fat Mass Loss." American Journal of Clinical Nutrition.
View source (PubMed) →
Fortiv is not a medical device and does not provide medical advice. Talk to your physician before starting a new exercise or nutrition program. See our Terms of Service for more.