Periodisation Explained: How to Plan Your Triathlon Year

Periodisation is the process of structuring your training into phases across the year so that you arrive at your target race in peak condition. Without it, most triathletes end up training at a similar effort level week after week — never building systematically, never recovering enough, and never peaking at the right time. Understanding and applying even a basic periodised approach can transform your race results.

The Four Main Training Phases

A complete triathlon training year is typically divided into four phases, each with a specific physiological goal:

• Base Phase — Building aerobic engine, improving technique, establishing consistency. Low intensity, high volume. Duration: 8–16 weeks depending on your event distance.
• Build Phase — Adding intensity and discipline-specific fitness. Includes threshold work, longer bricks and open water practice. Duration: 6–10 weeks.
• Peak Phase — Race simulation, highest training stress. Includes race-pace sessions, course-specific prep and mental rehearsal. Duration: 2–4 weeks.
• Taper Phase — Reducing volume while maintaining intensity. Allows your body to absorb training and arrive fresh on race day. Duration: 1–3 weeks.

How to Plan Your Triathlon Year

Start by identifying your A-race — the event you most want to perform well at. Work backwards from that date to map out your phases. If your A-race is in July, a periodised plan might look like this:

• November–February: Base phase — long, easy aerobic work, indoor turbo sessions, pool technique focus
• March–May: Build phase — threshold runs, sweet spot bike efforts, open water swimming starts
• June: Peak phase — race-pace sessions, brick workouts, full race simulations
• Early July: Taper — sharpen with short race-pace efforts, reduce overall volume by 40–60%
• Mid-July: A-race

Micro, Meso and Macro Cycles

Within each phase, training is further structured into cycles. A macro cycle is your full training year. A meso cycle is a 3–6 week block with a specific focus (such as swim technique or bike endurance). A micro cycle is a single training week. Within each micro cycle, balance your hard sessions (intervals, threshold, long rides) against easy sessions and rest days so that stress and recovery are in the right proportion.

How Hard Should Each Phase Be?

A common approach is the 80/20 rule: 80% of your training should be easy (zone 1–2), with 20% at higher intensities. During the base phase, this ratio leans even more towards easy work. In the build and peak phases, the intensity of that 20% increases — but the ratio stays roughly the same. This prevents overtraining while still delivering the stimulus needed to improve. If you find yourself training hard most days and feeling flat, it is almost always a sign that your periodisation has drifted too intense.

Adapting for Multiple Races

Most triathletes race more than once a year. If you have a B-race before your A-race, treat it as a hard training day rather than a full peak. Reduce your taper to 5–7 days, race to effort rather than targeting a PB, and then continue building towards your main goal. This keeps your season structured without derailing your overall progression.