An individualized threshold and training-zone report.
PRhealthier Lactate Test turns data from a blood lactate step-test into an individualized threshold and training-zone report. Purpose-built for the coach’s workflow.
Core Features
What the app computes from a single step test, end to end.
Individualized LT1 detection
A five-tier chain: strict, relaxed, and lenient rise-above-baseline detection, then semi-log rescue, then fixed 2.0 mmol/L fallback.
Fixed and individualized LT2
Fixed 4.0 mmol/L as the headline reference, plus an individualized LT2 chain of Modified Dmax, Classic Dmax, and fixed-4.0 fallback.
Sport-scoped training-zone models
5-Zone (Calculated LT1/LT2), Olympiatoppen, Friel-derived, Coggan-derived, and Daniels-derived, all calculated from the detected thresholds and shown by sport where relevant.
Practical per-zone targets
Power, heart rate, speed, and pace for every zone: the numbers athletes actually train with.
Protocol feedback
Flags structural issues in the test itself, so next time you can improve data collection.
Athlete-progress comparison
Compare up to three saved tests side-by-side. See how thresholds and the curve shape evolve across a training block.
App Screens
A full pass through the app, from the workspace and test entry to the lactate curve, threshold estimates, comparison, zone models, export, and built-in references.
One-page workspace
Athletes, saved tests, lactate curve, and estimate summary on a single iPad screen, with no hunting between views.
Structured test entry
Capture sport, date, environment, resting lactate, and each step’s lactate, heart rate, duration, distance, and pace.
Lactate curve
Plot lactate against heart rate, pace, power, or speed, with training zones shaded in the background.
Multi-axis view
Overlay pace with heart rate, or power with heart rate, on dual axes to see both physiological responses tracked against the curve.
Threshold estimates
LT1, LT2, FTP estimate, predicted VO2max, and practical power and heart-rate targets for each training zone.
Filter testing history
Narrow saved tests by sport and date range to pull up the session you need.
Side-by-side comparison
Overlay the current test with up to three saved tests to see whether thresholds and the whole curve have shifted.
Training zone models
Switch between 5-Zone (Calculated LT1/LT2), Olympiatoppen, and sport-specific derived models, set independently for running and cycling.
PDF and CSV export
Generate a coach-ready PDF report or export raw step data as CSV for spreadsheets and downstream analysis.
Built-in references
Calculation methods, glossary, training zone models, protocol suggestions, and blood-sample best practices, all inside the app.
Your most important PR is the one that keeps you healthy.
PRhealthier exists to realign endurance training with the reason many athletes started training in the first place: to be healthier. Somewhere in the pursuit of the next Personal Record (PR), that goal often fades. Recovery gets skipped. Sleep is sacrified. Training begins to work against the life it was meant to improve.
The most important PR isn’t a race time. It’s the one that keeps cardiovascular fitness where they should be for decades, not just for a season. Training inside the right physiological zones, grounded in real threshold data, is a path to both long-term health and sustainable performance.
This is PRhealthier Lactate Test’s mission: turn blood-lactate step test into individualized thresholds and training zones that make the training you’re already doing, produce the health benefits you wanted when you started your exercise journey.
PRhealthier was created by Bruno Oliveira, MD. Learn more about his professional background at brunooliveiramd.com.
Zone-based training isn’t a trend. It’s the evidence.
Endurance work below the first lactate threshold (LT1) drives the adaptations that matter long after the finish line: mitochondrial density, fat oxidation, metabolic flexibility, and improved cardiovascular health. These are the same adaptations associated with lower risk of type 2 diabetes, metabolic syndrome, and cardiovascular disease.
VO2max is one of the strongest single predictors of all-cause mortality, on par with hypertension and smoking as a risk factor. It is developed most efficiently with controlled work above the second lactate threshold (LT2), and those intervals only land correctly when LT2 is actually known.
The problem is that population formulas; a percentage of HRmax, an FTP guessed from a hard ride; misplace LT1 and LT2 for most athletes. The result is too much time in the gray zone: too hard for aerobic development, too easy for VO2max, accumulating fatigue without the adaptation. A lactate step test pins LT1 and LT2 down for the individual, so every zone downstream reflects physiology rather than assumption.
References
- LT1 / Zone 2; mitochondrial biogenesis. Holloszy JO. J Biol Chem. 1967;242(9):2278–82. · Bishop DJ, Granata C, Eynon N. Biochim Biophys Acta. 2014;1840(4):1266–75. doi:10.1016/j.bbagen.2013.10.012 · Hood DA, Memme JM, Oliveira AN, Triolo M. Annu Rev Physiol. 2019;81:19–41. doi:10.1146/annurev-physiol-020518-114310
- Fat oxidation at sub-LT1 intensities. Achten J, Gleeson M, Jeukendrup AE. Med Sci Sports Exerc. 2002;34(1):92–97. · San-Millán I, Brooks GA. Sports Med. 2018;48(2):467–479. doi:10.1007/s40279-017-0751-x
- Metabolic flexibility. Goodpaster BH, Sparks LM. Cell Metab. 2017;25(5):1027–1036. doi:10.1016/j.cmet.2017.04.015
- Cardiorespiratory fitness and all-cause mortality. Kodama S, et al. JAMA. 2009;301(19):2024–35. doi:10.1001/jama.2009.681 · Ross R, et al. Circulation. 2016;134(24):e653–e699. doi:10.1161/CIR.0000000000000461 · Mandsager K, et al. JAMA Netw Open. 2018;1(6):e183605. doi:10.1001/jamanetworkopen.2018.183605
- Type 2 diabetes and metabolic syndrome risk reduction. Colberg SR, et al. Diabetes Care. 2016;39(11):2065–2079. doi:10.2337/dc16-1728 · Pattyn N, et al. Sports Med. 2013;43(2):121–133. doi:10.1007/s40279-012-0003-z
- Supra-LT2 interval work for VO2max. Helgerud J, et al. Med Sci Sports Exerc. 2007;39(4):665–671. · Milanović Z, Sporiš G, Weston M. Sports Med. 2015;45(10):1469–1481. doi:10.1007/s40279-015-0365-0 · Bacon AP, et al. PLoS One. 2013;8(9):e73182. · MacInnis MJ, Gibala MJ. J Physiol. 2017;595(9):2915–2930. doi:10.1113/JP273196 · Buchheit M, Laursen PB. Sports Med. 2013;43(5):313–338.
- LT2 as the physiologic anchor; critique of population formulas. Faude O, Kindermann W, Meyer T. Sports Med. 2009;39(6):469–490. · Beneke R. Eur J Appl Physiol. 2003;89(1):95–99. · Jamnick NA, et al. Sports Med. 2020;50(10):1729–1756. doi:10.1007/s40279-020-01322-8 · Tanaka H, Monahan KD, Seals DR. J Am Coll Cardiol. 2001;37(1):153–156.
- Polarized training and the gray-zone problem. Seiler S. Int J Sports Physiol Perform. 2010;5(3):276–291. · Stöggl TL, Sperlich B. Front Physiol. 2015;6:295. · Esteve-Lanao J, et al. J Strength Cond Res. 2007;21(3):943–949. · Foster C, et al. Med Sci Sports Exerc. 2022;54(6):1028–1031.