Triathlon Training Volume: What Age-Group Athletes Actually Do

We finally have an objective triathlon training volume number to measure against — not a survey, not a forum poll, but 34,731 logged sessions pulled straight out of TrainingPeaks. The weekly averages are interesting. What the same dataset says about how that weekly number should move across a year is the part worth considering.

The study is Wells, Hoffmann, Bruce, Kremer and Dwyer, in Frontiers in Sports and Active Living (vol. 8, April 30, 2026): roughly six months of data collection from 95 age-group triathletes across 25 countries — mean age 48.0 ± 12.2, 77 men and 18 women — covering 34,731 sessions and 2,177 individual training weeks, averaging 22.9 weeks per athlete.

The Real Triathlon Training Volume Numbers — And Why They Are Not Your Targets

Here is what the cohort actually did, split by race distance preference:

Metric (weekly)	Long-course athletes	Short-course athletes
Duration	615 min (≈10h15)	507 min (≈8h27)
Distance (all three sports)	171 km	118 km
TSS	574	452

Long-course athletes trained more on every measure, and the differences were statistically significant — a sanity check that the dataset behaves the way you would expect.

Now the honesty, right next to the headline figures rather than buried under them. n=95 is a small sample. Ninety-five people is a modest cohort by any standard, and it is a retrospective cohort of self-selected TrainingPeaks users — recruited through social media, triathlon forums and TrainingPeaks' own newsletters — not a controlled trial. The authors say so plainly: respondents are "likely to be more motivated, technologically engaged, and training-consistent than the wider population." The cohort also skewed 69.3% long-course, with only 11.9% short-course specialists, so the short-course column above rests on a genuinely thin slice of athletes.

Which brings us to what matters most here: an average is not a prescription. Nothing in this paper says 615 minutes a week is the right dose for you. It says that is roughly the middle of a group of committed, tech-engaged, mostly long-course athletes who chose to hand over their data. If you train 7 hours a week and you are progressing, racing well and staying healthy, this is not an instruction to add three hours. Use the number the way you use a CTL trend line — as orientation, not a verdict.

The Genuinely Good News: Age Did Not Predict Training Load — and Sex Probably Doesn't Either

This is the finding worth leading with. Neither age nor sex was associated with training load (p > 0.05). For age the null result was emphatic across all three measures — p = 0.99 for duration, p = 0.76 for distance, p = 0.89 for TSS. In a cohort with a mean age of 48 and a spread of more than twelve years either side, the 55-year-olds were not quietly training less than the 35-year-olds.

That is useful evidence for masters athletes, and it lines up with what we see on our own roster in Austin and Waco. Plenty of physiology genuinely shifts after 40 — we covered what actually declines and what you can still train — but the capacity to carry a real weekly load is not automatically one of them. If you have assumed a lower ceiling because of the number in your age-group field, this dataset does not support that.

The sex finding needs a caveat stated out loud. The cohort was 77 men to 18 women, and the authors are explicit that this imbalance "reduces statistical power to detect sex differences." A null result in an 81/19 split is weak evidence of no difference — it is closer to an absence of evidence. So the honest reading is not "this proves men and women train identically." It is: within this cohort, women's weekly load looked like the men's, and nothing here suggests a woman aiming at a 70.3 or an IRONMAN should be planning a structurally smaller week. Given that women are the fastest-growing group in IRONMAN, this is a question the sport needs a much larger dataset to answer properly.

Your Triathlon Training Volume Most Likely Should Swing Across the Year

Here is where the study stops describing and starts arguing. The researchers sorted every training week into one of four self-reported phases — General/Base, Specific, Taper/Race/Post, and Off-Season — and load varied significantly across them.

In the paper's own words: "Relative to the General phase, measures of TL were 21% higher in the Specific phase, 14% lower in the Taper/Race/Post phase and 38% lower in the Off season phase."

Training phase	Load vs. General/Base phase	Reported weekly values
Specific (build)	+21%	556 min, 166 km, 620 TSS
General / Base	reference	not reported separately
Taper / Race / Post	−14%	not reported separately
Off-Season	−38%	340 min, 84 km, 364 TSS

Put the two phases the paper does quantify side by side and the shape of a properly periodized year appears. The specific phase carries 556 minutes a week against the off-season's 340 — about 60% more weekly training time. TSS goes 364 to 620, roughly 70% higher. Weekly distance very nearly doubles, 84 km to 166 km.

That is the argument. A year that swings produces adaptation a flat year cannot, and it asks for no extra annual training time — only a different distribution of the hours you already give the sport. A well-built season is not one number repeated fifty-two times; the gap between your quietest month and your hardest month should be measured in tens of percent. If your own line has been running level, that swing is sitting there unspent, and it is the cheapest adaptation available to you.

Two honest notes on the table. Phases were self-reported, so the labels carry each athlete's own interpretation. And the −38% off-season figure does not reconcile with the paper's own published absolutes: the off-season's 340 min/wk implies a General phase near 548, while the Specific phase's 556 min/wk implies one near 460. Treat the direction and rough magnitude as solid, and the exact −38% as the authors' summary rather than a number you can verify.

The Self-Audit: Where Do Your Last Twelve Weeks Actually Sit?

This takes about fifteen minutes and it is worth doing before you plan anything. Open your last four to twelve weeks and answer four questions.

1. What is your true weekly average?

Not your best week, and not your intended week — the mean of the last eight, including the ones that got cut short. It usually lands below the number you would have guessed, and knowing the real figure is what makes everything after it honest.

2. What is the spread between your biggest and smallest week?

If your heaviest and lightest weeks sit within about 20% of each other, you are training a flat line — and the cohort's phase data suggests a healthy season carries far more range.

3. Which phase are you actually in — and does your load match it?

Name the phase honestly. A build block running at base-block volume is a base block with a build block's name on it.

4. Is the trend rising, flat or falling — and is that on purpose?

Any of the three can be correct; what matters is whether you chose it. For a structured way through this without disappearing into the dashboard, we wrote how to analyze your training data without overthinking it.

What Your Next Twelve Weeks Should Look Like

Take the audit and build forward. For an athlete pointed at a late-season 70.3 or IRONMAN, the shape the data supports looks roughly like this.

Weeks 1–3 — establish the honest baseline. Train at your real current average, not your aspirational one, and keep the bulk of it genuinely aerobic. If your easy work has drifted upward, Zone 2 done properly is the highest-leverage fix available to you.

Weeks 4–9 — build a real specific phase. This is where the +21% lives. If your base weeks average 8 hours, a genuine specific block runs closer to 9h45 with race-specific intensity layered in. Step up over two or three weeks, not in one jump, and keep the recovery week genuinely recovering.

Weeks 10–12 — taper into the race. The cohort dropped roughly 14% into the taper/race window, which is a smaller cut than many athletes expect and a reminder that a taper reduces volume without abandoning intensity. Executing the final weeks well is a skill of its own.

And then actually take the off-season. The 38% drop is not the cohort falling apart in November — it is the phase that makes next year's specific block possible. Planning that down-cycle deliberately is what off-season success is built on.

The Bottom Line

The headline numbers from this study are worth knowing: roughly 10 hours a week for long-course age-groupers, 8.5 for short-course, with no meaningful difference by age or sex. Hold them lightly — n=95, self-selected, mostly male, mostly long-course — and never as a target to chase.

The finding to actually act on is the one underneath. Weekly load in this cohort swung roughly 60% in duration between the off-season and the specific phase. A year that moves like that produces adaptation a flat year cannot, and it costs nothing extra — it is the same annual training time, distributed with intent.

If you would like help turning your own self-audit into an actionable and interactive training plan that sharpens your strengths and supports your weaknesses, set up a call with us now, and we will help you be ready for your best race day!