16-Week 70.3 Intermediate Training Plan

This 16-week training plan prepares intermediate triathletes for a successful 70.3 (half Ironman) race. The plan balances building endurance, developing race-specific fitness, and maintaining recovery to arrive at race day strong and confident.

Prerequisites

Before starting this plan, you should meet these baseline fitness standards:

• Swim 1500m continuously at comfortable effort
• Ride for 2 hours at steady pace
• Run 10K without walking
• Currently training 4-6 hours per week consistently
• No significant injuries or health concerns

If you don’t yet meet these standards, spend 4-8 weeks building your base fitness before starting this plan. Rushing into 70.3 training without adequate foundation increases injury risk and reduces the likelihood of race success.

Plan Overview

The 16-week plan divides into four distinct phases, each with specific training objectives:

Base Phase (Weeks 1-4): Establishes aerobic foundation and builds training volume gradually. Focus on consistent training at comfortable efforts with emphasis on technique and form. Weekly volume: 7-9 hours.

Build Phase (Weeks 5-10): Develops race-specific fitness through threshold work, tempo sessions, and increasing long ride/run durations. Introduces brick sessions to practice bike-to-run transitions. Weekly volume: 9-12 hours, peaking at 14 hours in week 10.

Peak Phase (Weeks 11-14): Sharpens race fitness with intense interval work whilst maintaining endurance through long sessions. Highest training stress of the plan. Weekly volume: 10-14 hours.

Taper Phase (Weeks 15-16): Reduces volume whilst maintaining intensity to arrive at race day fresh and ready. Weekly volume drops to 6-7 hours in week 15, then 3-4 hours in race week.

Weekly Structure

Each week follows a consistent pattern that balances training stress with recovery:

• Monday: Rest or easy recovery swim
• Tuesday: Quality swim session (intervals or technique focus)
• Wednesday: Bike interval or tempo session
• Thursday: Run workout (intervals, tempo, or hills)
• Friday: Easy swim or complete rest
• Saturday: Long bike ride, often followed by short brick run
• Sunday: Long run or alternative long bike + swim combination

This structure ensures adequate recovery between hard sessions whilst progressively building fitness across all three disciplines.

Sample Build Phase Week (Week 8)

Week 8 represents a typical build phase week with approximately 12 hours of training:

Monday: Complete rest or 30-minute easy recovery swim

Tuesday: Swim—60 minutes including warm-up, 5 x 400m at threshold effort with 45 seconds rest, cool-down. Total distance: 2500-2800m.

Wednesday: Bike—90 minutes including 3 x 15 minutes at tempo (zone 3) with 5 minutes easy spinning between efforts. Warm-up and cool-down bookend the session.

Thursday: Run—60 minutes including warm-up, 4 x 5 minutes at threshold effort with 2 minutes easy recovery, cool-down. Total distance: approximately 10-12K depending on pace.

Friday: Swim—45 minutes easy technique work, drills, and relaxed swimming. Active recovery day.

Saturday: Bike-run brick—3 hours on bike at steady effort (zone 2-3) immediately followed by 20-minute run at race pace. Practice nutrition strategy during bike portion.

Sunday: Run—90 minutes at conversational pace on varied terrain. Focus on building endurance at comfortable effort. Total distance: 16-20K depending on pace.

This week combines endurance building through long sessions with quality intervals to develop race-specific fitness. The brick session on Saturday specifically prepares you for running off the bike on race day.

Linked Training Sessions

Throughout this plan, you’ll complete various structured sessions designed to develop specific aspects of your triathlon fitness. Browse the linked sessions below for detailed workout structures, coaching notes, and technique guidance.

These sessions represent the types of workouts you’ll encounter during the plan. Use them as templates, adjusting durations and intensities to match your current fitness and the specific week of training.

Key Training Principles

Progressive Overload: Training volume and intensity increase gradually throughout the plan. Each week builds on the previous week’s adaptations. Resist the temptation to do more than prescribed—more is not always better.

Recovery Weeks: Every third or fourth week reduces volume by 20-30% to allow adaptation and prevent overtraining. These recovery weeks are not optional—they’re when your body actually gets stronger.

Race-Specific Training: As race day approaches, training increasingly mimics race conditions. Long rides at race pace, brick sessions, and practicing your nutrition strategy ensure you’re prepared for the specific demands of 70.3 racing.

Flexibility: Life happens. Missed sessions don’t require panic or attempting to “make up” workouts by doubling up. Simply continue with the plan as written. Consistency over 16 weeks matters far more than perfection in any single week.

Nutrition and Fuelling Strategy

Use long training sessions to develop and test your race-day nutrition plan. For 70.3 racing, you’ll need to consume 60-90g of carbohydrates per hour during the bike leg, then continue fuelling on the run albeit at slightly reduced rates.

Experiment with different products—gels, bars, sports drinks—during training to find what your stomach tolerates. What works in a 60-minute session might not work in a 5-6 hour race, so practice matters.

Hydration equally demands attention. Practice drinking whilst cycling and establish your sweat rate to understand individual fluid needs. Don’t wait until race week to sort this out.

Race Week and Taper

The final two weeks dramatically reduce training volume whilst maintaining some intensity to keep your body sharp. Trust the taper—16 weeks of training have built your fitness. These final weeks are about arriving at the start line rested, not gaining last-minute fitness.

Focus on sleep, nutrition, and mental preparation during taper. Get your bike serviced, organise your transition bag, and visualise your race execution. The physical work is done; now prepare mentally.

Race Day Execution

All your training prepares you to execute a smart race. Start conservatively in the swim, pace the bike at sustainable effort (you should finish feeling like you could have gone slightly harder), and run with discipline rather than emotion.

The athletes who execute best rarely blow up. They pace intelligently, fuel consistently, and manage their effort throughout the entire race distance. Your training has built the engine—race day is about being the smartest driver.

Follow this plan with commitment and consistency, listen to your body, and you’ll arrive at your 70.3 race ready to perform at your best.