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Race Your Fastest 70.3 Bike Split and Run Stronger

Best Bike Split turns your power, course, and conditions into a precise Ironman 70.3 pacing plan — so you're ready to run.

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Half Ironman racing lives and dies on bike pacing. Too aggressive on the first 30 miles and you'll spend the back half of the course just surviving — and your half marathon turns into a death march. Too conservative and you leave minutes on the table you'll never get back. Best Bike Split's physics-based modeling creates 70.3-specific pacing plans that maximize your bike split while protecting the legs you'll need for 13.1 miles of running — dialed in to your exact course, conditions, and fitness.

The 70.3 Bike Pacing Challenge

Ride Fast Without Destroying Your Run

The 56-mile bike leg is the make-or-break moment of every 70.3. Too aggressive and your legs are blown by mile 40. Too conservative and you've handed minutes to every competitor willing to push. The solution? Science-based variable power pacing built specifically for the demands of half Ironman racing.

The Problem

Traditional steady-state pacing — like riding a flat 78% of FTP for all 56 miles — ignores course reality. Hills, wind, technical sections, and race-day adrenaline all create moments where steady watts mean you're either overcooking the effort or leaving speed on the table.

The BBS Solution

Best Bike Split analyzes your entire 70.3 course — elevation changes, road surfaces, wind direction and calculates the exact variable power targets to maximize bike speed while managing fatigue before the run. The result is a custom plan, not a single number to chase.

The Result

70.3 athletes using Best Bike Split consistently report faster bike splits paired with stronger half marathon performances. Our algorithms eliminate the most common 70.3 mistake: going too hard in the first half of the bike and paying for it over 13.1 miles.

Our Top Features

Everything You Need for Your Perfect 70.3 Bike Leg

Predict your 70.3 bike split, plan your power from your own data, and step off the bike in T2 ready to run — not just survive. Get more information about our top features, including the new Course Builder.

Predict your exact 70.3 bike split before race day

Know your target time before you ever toe the line, with accuracy within 2–3% when power data and conditions are correct. Understand exactly where on your specific 70.3 course you'll gain time on climbs or lose it in a headwind — and plan your race strategy around it.

Optimize power so you run your best half marathon

Our 70.3-specific algorithms calculate the power ceiling that maximizes bike speed without compromising run performance. See projected Training Stress Score (TSS), Intensity Factor, and fatigue metrics calibrated for a 56-mile bike leg followed by 13.1 miles of running — not just the bike split in isolation.

Train the exact demands of your 70.3, indoors or outdoors

Upload your 70.3 race plan to Zwift, TrainerRoad, or your smart trainer for indoor workouts that replicate your exact race-day power profile mile by mile. Take it outside with workout files for Garmin or Wahoo devices for course-specific outdoor training before the big day.

Follow real-time power guidance on your Garmin or Wahoo

Execute your perfect 70.3 pacing plan on race day with turn-by-turn power targets loaded directly to your bike computer. See your plan, current power, and time ahead or behind pace in real-time throughout the 56-mile bike leg — so you never have to guess whether you're on track.

Choose the fastest equipment and race strategy for your 70.3

Model different scenarios before race day: aero wheels vs. lightweight, aggressive position vs. comfortable, conservative start vs. pushing the hills. Understand the time impact of every equipment and pacing decision so you show up on race morning with zero guesswork.

See how fitness, drag, weight, and weather change your 70.3 time

Test what-if scenarios before committing to your plan. See how losing 5 pounds impacts your bike split on a hilly 70.3 course. Understand how a 15mph crosswind through miles 30–45 should change your pacing strategy and model different FTP levels to set realistic finishing goals all with our Time Analysis Tool.

Pace the 56 miles perfectly so you have legs for the run

The most common 70.3 mistake is overcooking the bike by just 3–5% — it feels fine at mile 20 and costs you 10 minutes on the run. Best Bike Split's variable power algorithm prevents that error before it happens. Our plans account for cumulative fatigue, ensuring you don't exceed sustainable effort even when adrenaline and competition tempt you to push harder than your race plan allows.

Learn from real ride data to race smarter every season

Upload your actual 70.3 race files and compare against your plan. See where you held target power and where you deviated. Analyze the impact of those pacing variations on your run performance. Use these insights to refine your strategy for the next race and continuously improve your 70.3 execution season over season.

Plan with physics-based modeling trusted by pros

Best Bike Split's algorithms are used by World Tour cycling teams and professional triathletes to optimize race performance. The same physics-based modeling that helps pros win races is available to age group 70.3 athletes. Our math accounts for aerodynamics, rolling resistance, gradient, wind, and power output to calculate the fastest possible way to complete your 70.3 course.

Start race morning with total confidence in your 70.3 strategy

Eliminate pre-race anxiety about pacing. Walk into T1 knowing exactly what power to hold on every section of the course. No more guessing whether to push the opening hills or stay conservative through the windy back section. Execute your plan with complete confidence that it's optimized for your fastest 70.3 bike split — and your strongest half marathon run.

Triathlon Pacing Plans

How 70.3 Pacing Compares to Other Triathlon Distances

Sprint Triathlon Bike Pacing

With a short, intense bike leg followed immediately by a 5K run, sprint triathlons require disciplined threshold pacing. Our plans typically target 85-95% of FTP depending on course profile and your run strength, with precise power targets that prevent early fatigue while maximizing bike speed.

  • Predict your exact bike split before race day
  • Dial in aggressive pacing without blowing up your run
  • Optimize speed for short, high-intensity efforts
  • Execute perfectly with real-time power targets
85–95%
FTP Target
12–20 mi
Bike Distance
5K
Run Distance
age group triathlete using power pacing for a sprint triathlon

Olympic Distance Power Plans

Olympic distance racing demands careful power management at and near threshold. Best Bike Split helps you find the power ceiling that allows for a competitive 40K bike split without compromising your 10K run performance. Most athletes target 80-85% FTP with strategic surges on key sections.

  • Find the fastest sustainable 40K power
  • Balance bike speed with a strong 10K run
  • Model terrain, wind, and course dynamics
  • Train precisely for race-day demands
80–85%
FTP Target
40K
Bike Distance
10K
Run Distance
olympic distance triathlon pacing with garmin

70.3 Bike Pacing Strategy

Half Ironman racing sits in the sweet spot of triathlon — more intensity than a full Ironman, more distance than Olympic. Most athletes target 75–80% of FTP across 56 miles, but the right number depends on your course profile, heat, your individual bike-to-run strength, and how the race is laid out. Best Bike Split models all of it.

  • Execute variable power across all 56 miles
  • Adapt pacing for hills, wind, and heat
  • Protect energy for a fast half marathon
  • Validate nutrition and effort before race day
75–80%
FTP Target
56 mi
Bike Distance
13.1 mi
Run Distance
70.3 athlete following precision pacing plan on bike leg

Ironman Bike Pacing Plan

The Ironman bike leg is a 112-mile exercise in patience and precision. Most age groupers perform best at 68-72% of FTP, but this varies significantly based on course difficulty, temperature, and individual run-to-bike strength ratios. See how pro triathlete TJ Tollakson used Best Bike Split to achieve a record-breaking Ironman performance with precise power pacing.

  • Distribute effort perfectly across 112 miles
  • Prevent late-race fatigue and pacing mistakes
  • Model heat, terrain, and endurance limits
  • Set up your strongest possible marathon
68–72%
FTP Target
112 mi
Bike Distance
26.2 mi
Run Distance
triathlete using power meter on Ironman bike course

Easy Setup

Create Your 70.3 Pacing Plan in 3 Steps

triathlete power profile

Build Your Athlete Profile

Enter your FTP, weight, bike specs, and aero data to generate precise 70.3 race predictions. Don't know your CdA? Our system can estimate it from your position and equipment or from a past ride — so you can start planning with confidence even without a wind tunnel.

triathlon specific courses

Select Your 70.3 Course

Choose from thousands of existing 70.3 courses — most Ironman 70.3 and Challenge Family venues are already in our database — or upload your own GPX file. Our database includes detailed elevation profiles and road surfaces, plus historical or forecasted weather for accurate split predictions.

custom triathlon pacing plan

Your Personalized 70.3 Plan

Receive a detailed, segment-by-segment 70.3 bike pacing strategy with variable power targets optimized for every section of your course. See your predicted bike split, Intensity Factor, TSS, and exactly how your pacing strategy balances speed with half marathon readiness.

Train and Race with Your Plan

Download your plan to Zwift, TrainerRoad, or any ERG-mode trainer for indoor training. Export to Garmin or Wahoo for outdoor training rides and race-day execution. Practice makes perfect — rehearse your exact 70.3 race plan in training before the big day.

Create Free 70.3 Pacing Plan

Indoor and Outdoor Workouts

Train with Your 70.3 Bike Pacing Plan

Indoor Course Simulation

Why guess at race-day power targets during your winter training blocks? Upload your 70.3 plan to Zwift or TrainerRoad and ride the exact power profile you'll execute on race day. Practice holding watts on the climbs, recovering efficiently on descents, and managing your average power through the wind-exposed sections — all from your pain cave.

Outdoor Race Rehearsals

Load your 70.3 pacing plan to your Garmin or Wahoo device for outdoor execution. If you can ride the actual race course beforehand, do it with your plan loaded. If not, simulate the effort on similar terrain. Follow your plan's power targets and build the muscle memory your body needs for confident race-day execution.

Brick Workout Integration

Best Bike Split plans are built for triathlon brick workouts. Execute your race-day 70.3 bike power plan, then transition directly to your target half marathon pace. This training teaches your body to run efficiently on fatigued legs — and validates your bike pacing before money is on the line.

Progress Tracking

Compare your training rides against your plan. Are you holding the target watts? Do you step off the bike feeling like you could run 13.1 miles hard? Use real ride data to refine your plan, adjust FTP estimates, and dial in your race-day strategy before you ever hit the start chute.

Wahoo/Garmin bike computer displaying 70.3 power targets from Best Bike Split

Top Half Ironman Events

Use Best Bike Split for Your Next 70.3

Ironman 70.3 Chattanooga

A scenic Tennessee half-distance classic featuring a current-assisted Tennessee River swim, rolling 56-mile bike course through northern Georgia, and a vibrant downtown run — ideal for athletes optimizing half-distance pacing strategy, elevation-based power modeling, and race execution on variable terrain.

Ironman 70.3 Alcúdia-Mallorca

A flagship Ironman Pro Series race on the Island of Mallorca, combining a calm bay swim, a demanding 90km bike through the Serra de Tramuntana mountains, and a flat beachside run — a world championship qualification race ideal for athletes modeling climber pacing strategy, normalized power output, and multi-terrain 70.3 race execution.

Ironman 70.3 Oceanside

The iconic North American season opener set along the Southern California coast, featuring an ocean swim in Oceanside Harbor, a fast and rolling bike through San Diego County inland terrain, and a flat beachfront run — a perennial Ironman Pro Series fixture ideal for benchmarking half-distance bike split performance and aerodynamic efficiency early in the season.

Ironman 70.3 Gulf Coast

A long-running half-distance event on Panama City Beach, Florida featuring an emerald Gulf swim, flat closed-road bike, and fast beachside run — a go-to race for athletes targeting personal records, optimizing flat-course power output, and executing heat-management pacing strategy.

Ironman 70.3 Texas

A fast and flat half-distance race set in Galveston with a Gulf of Mexico swim, coastal bike, and pancake-flat seawall run — ideal for athletes chasing half-ironman PRs, optimizing normalized power targets, and testing race-day nutrition and pacing strategy on a highly predictable course.

Ironman 70.3 Mont-Tremblant

A destination 70.3 set in the Laurentian Mountains of Quebec with a clean lake swim, challenging rolling bike, and a scenic run through the pedestrian village — ideal for athletes modeling variable elevation power demands and executing a half-distance pacing strategy.

Ironman 70.3 Oregon

Held in Salem, Oregon with a controlled river swim, flat and fast closed bike course, and a shaded run — an approachable yet competitive 70.3 course ideal for athletes targeting a breakthrough half-ironman finish time and experienced competitors dialing in FTP-based race pacing.

Ironman 70.3 Eagleman

A flat, fast, and notoriously heat-testing 70.3 on Maryland's Eastern Shore, featuring a Choptank River swim, pan-flat bike across open Chesapeake farmland, and an exposed run notorious for decisive race-day splits — a key event for athletes focused on raw speed and heat acclimatization strategies.

Ironman 70.3 Boulder

A high-altitude half-distance benchmark race set in Boulder, Colorado — one of the world's premier triathlon training hubs — with a reservoir swim, fast rolling bike through Boulder County roads, and a run through the city's iconic trail network. A key event for modeling altitude impact on power output, and aerobic pacing strategy.

Half Ironman FAQs

Ironman 70.3 Bike Pacing Questions

Most age group athletes perform best at 75–80% of FTP for a 70.3 — but the right number varies based on your course profile (flat vs. hilly), conditions (heat, wind), your personal bike-to-run strength ratio, and overall fitness. Best Bike Split models all of these variables to calculate your personal optimal power ceiling, not a one-size-fits-all percentage.

Half Ironman racing allows for meaningfully higher intensity than a full Ironman — typically 75–80% of FTP versus 68–72% for the full distance. The shorter bike leg (56 miles vs. 112 miles) and the half marathon instead of a full marathon allow for a more aggressive bike effort. Best Bike Split accounts for race distance and your specific run fitness when calculating optimal 70.3 power targets.

Olympic distance athletes can push closer to threshold — 80–85% FTP — over just 40 kilometers. The 70.3 bike leg is almost 2.5x longer, which demands a more conservative average intensity and tighter fatigue management. The key difference is how small errors in power judgment compound over 56 miles in ways they simply don't over 25.

While a power meter provides the most accurate race-day execution tool, Best Bike Split can create heart rate-based plans and pace-based guidance. For 70.3 racing specifically, we strongly recommend power meters — power is the most consistent pacing metric available when heat, fatigue, and adrenaline make heart rate and RPE unreliable.

Yes. Best Bike Split can estimate FTP based on recent ride data, or you can perform a 20-minute FTP test to establish your baseline. We also provide guidance on translating your FTP into training and racing power zones specific to 70.3 demands.

When power data, course information, and weather conditions are accurate, our physics-based modeling typically predicts 70.3 bike split times within 2–3%. Thousands of athletes validate these predictions every season across Ironman 70.3 and Challenge Family races worldwide.

It's the single biggest factor in 70.3 run performance outside of your base run fitness. By avoiding overcooking the first 20–30 miles and managing energy expenditure throughout the bike, you'll arrive in T2 with more glycogen, fresher legs, and the mental confidence to push the half marathon. Athletes who nail the 70.3 bike frequently run the last 5K faster than the first — athletes who overcook it almost never do.

Yes. Our database includes the vast majority of Ironman 70.3 and Challenge Family courses worldwide — from 70.3 World Championship venues, Ironman 70.3 St. George, Chattanooga, or Oceanside to local and regional events. Select your course from the database or upload a GPX file for any event not already listed.

Absolutely. Best Bike Split works for any half-iron-distance event regardless of brand — Ironman 70.3, Challenge, Rev3, CLASH, or any local 70.3-distance triathlon. Upload your course GPX file or build a custom course and our physics engine handles the rest.

Best Bike Split vs Old Methods

Why Best Bike Split Beats Traditional 70.3 Pacing

Steady-state pacing works on a trainer. It doesn't work on a real 70.3 course with hills, wind, and 56 miles of accumulated fatigue. Best Bike Split analyzes every element of your specific course to deliver a data-driven pacing plan that produces faster bike splits and stronger half marathon runs.

Old School Method Best Bike Split Method

Ride Steady State Power

"Just hold 77% of FTP for the whole 70.3 bike leg"

Variable Power Pacing

Calculate optimal power for every mile based on gradient, wind, road surface, and cumulative fatigue.

The Problem

Real 70.3 courses aren't flat training roads. Hills, headwinds, and technical sections all impact optimal power output. Riding steady watts means you're over-pacing climbs and accumulating fatigue — or under-pacing flat sections and losing time you'll never get back.

The Result

Faster 70.3 bike splits with less fatigue. More efficient use of your FTP across all 56 miles. A stronger half marathon off the bike.

Guessing your 70.3 bike split from a previous race on a different course isn't a strategy. Best Bike Split models your exact course, your current fitness, your equipment, and expected race-day conditions to deliver accurate split predictions before you ever leave home.

Old School Method Best Bike Split Method

Guess Your Bike Split Time

"I went 2:35 on a flat course last year, so maybe 2:45 on this hilly one?"

Physics-Based Time Prediction

Model the exact 70.3 course you're racing with your power, weight, equipment, and expected conditions.

The Problem

Every 70.3 course is different. Elevation gain, wind exposure, road surface quality, and temperature all change your split significantly. Past performance on a different course doesn't predict what you'll do on your next one.

The Result

Know your target 70.3 bike split to within minutes before race day. Plan nutrition timing, run targets, and overall race strategy around accurate, course-specific time predictions.

Join 150,000+ Athletes Already Racing Smarter

Stop guessing at 70.3 bike pacing. Stop following generic IF recommendations that don't account for your specific course, conditions, or fitness. Start using the same physics-based modeling trusted by pro triathletes and World Tour cycling teams — and race the 70.3 you've been training for.

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  • BBS AI Workout Builder
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  • Goal Race Time Model
  • Training Stress Score Model
  • Advanced Weather Feature
  • Advanced Surface Conditions
  • Time Analysis Tool

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  • Race Analytics Tool
  • Plan to Actual Comparison Tool
  • BBS AI Workout Builder
  • BBS AI Assistant
  • Workout Sync (top platforms)
  • Goal Race Time Model
  • Training Stress Score Model
  • Advanced Weather Feature
  • Advanced Surface Conditions
  • Time Analysis Tool

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CANYON//SRAM Racing partners with Best Bike Split
Team Jayco AlUla recommends power pacing
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