The Triathlete Blueprint Newsletter #113-Training Volume Can Make You... or Break You

Yan Busset
Jun 28
6 min read

Read time: 5min.

By Coach Yan Busset

Training Volume: Your Most Powerful Tool… If You Handle It Right

If there’s one factor in endurance training that’s simple and powerful, it’s volume. Not fancy gear, intervals, or marginal gains. Volume.

Training more boosts nearly every physical marker of endurance performance: VO₂max, mitochondrial density, aerobic efficiency, fat metabolism, capillarisation (1, 3, 4). But volume only works if you can sustain it. If not, it breaks you.

This article explores what increasing volume really means, how to do it wisely, when not to do it, and how to recognise if it's helping or harming your progresses.

Why volume works so well

Studies on recreational runners found that growing weekly volume to around 40–60 km led to VO₂max gains between 4 % and 12 % over 6–12 weeks, plus up to 5 % better time-trial results (1). Those improvements reflect better mitochondrial function, fat burning, capillary growth and aerobic efficiency. The more you train at easy to moderate intensity, the more your body adapts.

For beginners or athletes with low to moderate training history, increasing volume is one of the most direct levers for improvement. There’s a big window to explore.

But as you progress, that relationship changes. Simply piling on hours isn’t enough unless you work on intensity, structure and recovery.

More hours give more technical exposure too. More swim time teaches body feeling. More runs reinforce form. Volume is the foundation for everything else.

The key is not how hard you train but how long you can sustain it

It’s not about surviving a monster week. It’s about longevity.

The real question is not “Can I do this next week?” but “Could I keep this up for the next ten years?”

That means volume must fit into your life. Work, family, sleep, mental space. If training volume creates tension at home, affects your performance at work or adds stress you can’t recover from, then it’s not a long-term strategy.

Consistency always beats intensity.

Volume has its limits

Even solid gains from volume alone can hit a plateau. For trained athletes, adding more hours without adjusting structure is useless. A study on trained cyclists found that once a sufficient base is built, upping volume doesn’t always improve VO₂max or time-trial performance. What counts is how you distribute intensity (2).

This confirms your approach: volume helps, up to a point. After that, smarter structure and recovery matter more.

One exception: training camps

If you enter a period with fewer stressors, like a holiday or training camp, you have a window to raise volume temporarily. With less work and family pressure, recovery is easier and you can absorb more. That can help you unlock a new level. Just make sure you come back to sustainable volume afterward.

More volume doesn’t mean longer sessions

Volume doesn’t have to mean long workouts. You can build it up through frequency.

Four 30 minutes swims in a week develops feel for water better than one 2 hours session. Frequent short runs keep your form sharp and reduce injury risk.

If you’re a high-performing age-group athlete, a second longer ride midweek can help, but only if recovery supports it.

How to fit more training into everyday life

Here are some proven strategies to add volume without upending your routine:

Train early when life is calm, but never at the expense of sleep ( so go to bed earlier)
Head straight from work to training with gear ready, so you don’t lose momentum
Use your commute as aerobic training, bike or run part of it, or park halfway and finish by foot or bike
Stay in zone 1 or low zone 2 during those additions—don’t ever turn your commute into a race

Recovery and nutrition: the enablers of volume

You are less fit after a training session than before. Only recovery makes you stronger.

To add volume, you need more sleep, quality rest, naps where possible, and stress management. That means protecting your sleep and mental energy.

Your calorie intake must match your training load. Eat more on high volume days and ensure you get balanced macronutrients and micronutrients. Without proper recovery and fuel, increased volume becomes degradation.

How to manage intensity with higher volume

With added volume, it’s tempting to increase intensity too. But the 80/20 principle still applies. 80 % of training should be easy, zone 2 or below. As volume increases, that easy portion can shift lower: more mid zone 2, more zone 1 and active recovery. Grease the groove with more frequent easy sessions. Full recovery days can be simple zone 1 sessions.

Don’t mix volume increases with higher intensity simultaneously. It’s a fast track to burnout.

Avoid the pitfalls

Here are common traps to avoid:

Don’t increase volume too fast, limit progression to 7–10 % per week
Don’t use volume to escape frustration or chase ego, train with purpose
Don’t train without well-tested zones, verify your intensity thresholds first
Monitor recovery markers: sleep quality, resting heart rate, HRV, weight, mood. If they decline, volume isn’t being absorbed
Don’t ignore life stress, training stress + life stress = total stress on your system ( the you at work is the same you at training)
Don’t believe more hours always mean improvement, structured volume matters more

My own experience

During my competitive years, I focused mostly on short-course racing. I trained a lot, around 15 hours per week, which sounds like a lot, but for a full-time athlete like I was, it’s not that much. I put a heavy emphasis on intensity and quality, but I severely underestimated the value of low-intensity, high-volume work.

Looking back, this affected my races. Either I lacked the bike endurance to keep up or, if I managed to ride well, I had no legs left to run. My top-end speed was good, so I could hide it on short races, but I now see what I was missing. I lacked the aerobic Z2. Now that even short-course athletes today train huge volumes, almost similar to long-distance athletes. Back in the day lot of pro was doing high volume but with a lot of junk miles-

There is volume, and then there is effective volume. It’s not just about accumulating hours. You can do a lot with less if you do it right. But if you do have the space and structure to do it properly, volume can truly unlock your potential. If my present self could talk to my young self I would kick my own ass to go for more Z2.

Conclusion

Volume isn’t the alpha and omega. We all have different backgrounds and training hours limitations. You don’t need huge hours to start to enjoy triathlon. Creative low-volume adaptations can work too.

But to progress, volume is a core component of endurance performance. It must be sustainable, recoverable and tailored to your world. Beginners can gain rapidly with low volume. Experienced athletes should refine structure more than just add hours.

It comes back to one thing: know yourself, train smart, recover harder. It’s not about how much you train: it’s about how much you can absorb.

References

Barbosa RR, Melo RJP, Gomes JLB, Guimarães FJP, Costa MDC. Effect of aerobic training volume on VO₂max and time-trial performance in recreational runners: systematic review. Journal of Human Sport and Exercise. 2024;19(4):816‑829. https://www.jhse.ua.es/article/view/3551
Cove B, Chalmers S, Bennett H, et al. The effect of training distribution, duration, and volume on VO₂max and performance in trained cyclists: systematic review and meta‑analysis. Journal of Science and Medicine in Sport. 2024. https://www.sciencedirect.com/science/article/pii/S1440244024005966
Mølmen KS, Almquist NW, Skattebo Ø, et al. Effects of endurance training on mitochondrial and capillary growth in human skeletal muscle. Sports Medicine. 2024; published 2024. https://pubmed.ncbi.nlm.nih.gov/39390310
Andersen P, Henriksson J. Capillary supply of the quadriceps femoris muscle of man: adaptive response to exercise. The Journal of Physiology. 1977;270:677‑690. https://link.springer.com/article/10.1007/BF00943344