Endurance calculators.
Science-backed tools for runners, cyclists and triathletes. Used by Boston qualifiers and Kona finishers — free, instant, and no email wall to see your result.
Most popular
AI Nutrition Plan
Instant AI-generated race-day fueling plan: carbs/hour, sodium, fluids, product picks.
Open calculatorVDOT Race Predictor
Daniels VDOT from any race result. Predicts times across distances and gives E/M/T/I/R paces.
Open calculatorFTP & Power Zones
Estimate FTP from a 20-min or ramp test. Get 7 Coggan training zones and W/kg category.
Open calculatorHeart Rate Zones
5-zone HR breakdown using max HR or the Karvonen method with resting HR.
Open calculatorSweat & Sodium Loss
Calculate sweat rate and sodium loss from a simple weigh-in test. Build a real hydration plan.
Open calculatorCritical Swim Speed
Derive CSS from a 400m + 200m time trial. Get swim training zones in pool intervals.
Open calculatorMore training tools
Grade Adjusted Pace (GAP)
Convert hilly running pace to flat-equivalent GAP using the Minetti energy-cost model — same as Strava.
Open calculatorAltitude Pace
Convert sea-level pace to an equivalent altitude pace, with acclimatisation credit and per-distance penalties.
Open calculatorTreadmill Pace Conversion
Turn belt speed and incline into the equivalent outdoor road pace, plus a full speed-to-pace chart.
Open calculatorDew Point for Runners
Magnus-Tetens dew point from temperature + humidity, mapped to a runner-specific comfort scale.
Open calculatorHeat & Humidity Pace
Adjust running pace for temperature and humidity using heat index.
Open calculatorTriathlon Race Predictor
Physics-based bike model with race elevation. Predicts Sprint, Olympic, 70.3 and IM.
Open calculatorHalf Ironman 70.3 Predictor
Predict your 70.3 finish time and splits from training paces. Metric or imperial (US) units. Transitions baked in.
Open calculatorAI Bike Fit Analyzer
Real-time MediaPipe pose detection from your webcam. Measures knee, hip, back, ankle, arm & torso angles.
Open calculatorBoston Qualifier Calculator
Your BQ standard by age and division, the buffer the cutoff record supports, goal pace, and the equivalent times you need at other distances.
Open calculatorNYC Marathon Qualifier
Your NYRR guaranteed-entry standard by age, division and distance — marathon or eligible NYRR half — with the pace to run it.
Open calculatorHansons Marathon Pace
Easy, Marathon Pace, Strength, and Speed paces from your goal marathon time. Matches the Hansons Marathon Method protocol.
Open calculatorMarathon Pace & BQ Check
Convert goal time to per-km/mile pace and check it against your Boston Qualifying standard.
Open calculatorWeight & Pace Impact
See how a change in body weight affects running pace and cycling W/kg.
Open calculatorCarb Loading Plan
Personalized 3-day carb load by event distance. Grams per day + food equivalents.
Open calculatorRace Time Predictor
Equivalent times across every running distance from one recent result, via Riegel and Daniels-Gilbert.
Open calculatorIronman 140.6 Predictor
Full-distance finish time and splits from your standalone swim, bike and run paces. Transitions included.
Open calculatorYou have the numbers. Apex turns them into a training week.
Every tool on this page produces one number. Apex is what happens next: it takes your paces, zones and race date and writes the week, then rewrites it when you miss a session.
- A full plan generated from your own numbers
- Adaptive re-planning when the week goes sideways
- Check-ins, streaks and an in-app coach
$4.99/month or $49.99/year · 14-day free trial · No credit card required to start
Want a human reading the numbers with you?
1:1 coaching is the version where I look at your week, your history and your race, and make the call myself. Limited roster, application only.
Boston-based · Trilingual EN/PT/ES · RRCA · USAT · TrainingPeaks L2 · 12× Boston qualifier
How race-ready are you actually?
Twelve questions, ninety seconds. You get a scored breakdown across aerobic engine, strength, fuelling and recovery — plus the single fix that moves your race day the most.
Take the scorecard1:1 endurance coaching
Tiers, fit, and the full coaching philosophy — running, triathlon, Ironman, Boston.
Boston Marathon coach
12× BQ coach based in Boston — qualifying blocks, course strategy, race week.
About Coach Breno
Trilingual coach (EN/PT/ES), RRCA · USAT · TrainingPeaks L2, 18+ race wins since 2015.
Athlete testimonials
Real PRs, BQs and Kona/Ironman finishes from athletes coached 1:1.
Coaching results
Race results board: marathon PRs, BQs, podiums, IM and 70.3 finishes.
Press & features
Coverage in major running and endurance publications.
Find your plan (60-sec quiz)
Answer 6 questions to get a plan matched to your race, goal and history.
Book a free intro call
Free 20-min call with Coach Breno — discuss goals, fit, and the right plan.
Contact
Email, Boston address, and the fastest way to reach the coaching team.