Neil Gresham's Guide to Interval Training

Why anaerobic endurance?

Lucy Creamer on Head Intrinsica 7b+
Holcombe Quarry, South West England.
Photo: Tim Glasby

You're a redpointer, an onsighter or perhaps even a competition climber. The route concerned is a fairly standard looking 'middle distance' affair of 50-60 feet in height and pretty sustained looking. You give it your best shot and burn out just short of the belay. So what went wrong? Let's presume in this case that fatigue was responsible; that is to say, you performed the moves well, but you simply ran out of gas. But how could this be the case? There's no way that the move concerned was beyond the limits of your strength, nor was it any harder than the other moves on the route. Stranger still, you can be equally sure that you didn't fail because you were excessively pumped; the moves were too hard to allow you to hang in there and tolerate any quantiy of lactic acid. You were going nicely and then suddenly, with minimum warning, your fingers uncurled and you were off.

Quite simply, the physiological system which has let you down in this case is the one which requires you to produce energy anaerobically. In fact, anaerobic endurance is perhaps the single most important energy system used in climbing which, ironically, is also one of the least well understood. Even if you are a boulderer, you will need 'bottom-end' anaerobic endurance for longer problems or, conversely if you're an all-day multipitcher, there will still be occasions where you need 'top-end' anaerobic endurance for the harder sustained sections.

Anaerobic endurance defined

Correctly defined anaerobic endurance requires the ability to apply the persistent use of strength and power in a climate of lactic anaerobiosis. So in climbing terms this means doing relatively hard moves for a relatively long period! For example, between 15 and 30 sustained moves which are at 60-75% of your 1-move bouldering maximum, and for a duration of between 40 seconds and 2 minutes. Sounds like the sort of situation we've all been up against at some point! One thing's for sure, as an energy system it has an upper limit where work can no longer be sustained. After that critical time barrier, unless you find yourself on easier ground, where you can attempt to pay off your oxygen debt and disperse lactic acid aerobically, the only other option will be to fall off, or go away and extend your threshold!

Training for anaerobic endurance

John Arran at Chee Dale,
The Peak District, UK.
Photo: Berry Collection

Specificity is one of the most important training principles in climbing as with any other sport. In view of this it would be easy to conclude that in training for anaerobic endurance, all we have to do is go out and climb stacks of routes and circuits which fit the above criteria. Afterall, your average route at the gym is about the right length and intensity so, hey, let's just go climbing. If only it were that simple! Guaging the suitability of a route or circuit for anaerobic endurance is merely the first stage, the crux comes when trying to guage the level of difficulty, how many to do and most important of all, how long to rest.

Training to fail is failing to train

How many times have you heard that good old cliche 'no pain no gain'? As climbers we have been conditioned to believe that by going for the burn, maxing out and pushing ourselves to the point of failure and beyond that we are going to get fitter and climb harder. Let's take a step back for a second. It is a known fact that in order to target the cellular machinery required in anaerobic endurance for any sport, there must be a critical blend between the amount of work, it's difficulty (or intensity) and it's frequency. In other words there is an optimum level of training which must be sustained in order to tax and therefore extend your anaerobic threshold. Too intense and you won't achieve sufficient volume; too much volume and the intensity is compromised. It's a simple balancing equation.

Climbing below your aneorobic threshold

So clearly, if the first route or circuit you try in your anaerobic endurance session causes you to burn-out, by definition, the next one will either have to be easier, or you'll have to rest so long that the momentum of the session will be lost. How many times have you started your gym session by going for routes at your limit and the dropping your grade until you can barely get up your warm-ups. It feels like the right way to train 'cos it's seriously hard work each and every time you climb, but the reality is that you are not spending sufficient time flirting within that critical zone beneath your anaerobic threshold which induces the appropriate physiological adaptations.

Interval training for ultimate anaerobic endurance

It is fortunate for climbers that this complex issue of balancing the variables in an anaerobic endurance training session is well and truly understood in the more advanced World of mainstream sport. The answer to developing anaerobic endurance lies in one word: Intervals. During a training session, no sprinter or middle distance runner in their right mind would ever dream of running every repetition of a distance at their absolute maximum and reducing the pace accordingly for each one. They decide on a set pace, a set number of work intervals, a set recovery time (or rest interval) and they aim to compete all the work, but only just! - or perhaps to burn out only on the very last one. By definition, this means that the first few work intervals will feel relatively easy; but as the session progresses, you will start to feel under increasing pressure by the stop-watch, until, at the end, it will be all you can do to squeeze out that final interval. Hence there is progression within the session, which ultimately reaches an intensity climax.

The discovery of this simple principle and it's application to climbing by some of the top European Competition climbers goes a long way towards explaining the astonishing increase in the standard of 'middle distance climbing' in recent years.

Guidelines for interval training for climbing

The table belay shows a sample interval training structure for combining length and intensity of climbing work with the appropriate rest times for anaerobic  endurance.

Suggested interval training layout for the development of anaerobic endurance: