Filling the training parameter space

The marathon prediction equation produced by Tanda (2011) did not look at the performance of any sub-elite runners, his fastest was 2:47. In this post I have added in some data from a few faster runners - the results are surprising.

Tanda (2011) - A viewpoint

Giovanni Tanda (2011) looked at the marathon performance of 22 runners who had run a total of 46 marathons (over a 5 year period) at near flat-pace race effort (halfway splits <±4 min) - i.e. near optimal aerobically limited efforts. He looked for correlations between marathon performance time and the following elements of the training diary (warm-ups and recoveries were included):

Predicting marathon performance from training data

Those who train for a marathon following a pre-prepared plan, of which there are many available, should have a reasonable expectation of achieving their goal: a 3:15 marathon plan should get you a 3:15 marathon time if you execute both the plan and the race appropriately. Unfortunately runners train in the 'real-world' where sessions get skipped and targets missed. The effect of failing to precisely execute 'The Plan' is hard to predict. Can missing one day/week really have a measurable effect? The lack of predictability presents a serious problem to many runners and can lead to injury as they attempt to make-up for missed sessions or bonk badly in the race by failing to scale back their speed to match their lack of diligence in training.

What is a training load?

Training: pushing adaptations in limiting systems Most runners training for a marathon follow some form of standard plan containing a mix of running speeds and durations with a gradual build towards race day. The plans are constructed to induce adaptations within different systems that might limit marathon performance. These plans also contain elements that enable further training to occur - i.e. the concept of training to train. Whilst most runners are aware of the standard adaptations that are required: muscle mass, glycogen content, mitochondrial density and enzyme expression, capillary density, 'fibre-type', circulatory capacity (stroke volume etc), tendon and bone strength, mental capability, 'endurance' there is often little understanding as to just how specific or non-specific the types of training are in terms of the adaptations they produce. The result is that there is sometimes an impression that particular types of training can produce disproportionately large benefits. There are three of those types that have developed cult followings within the community: tempo running, hills/hard intervals and the long run. It is worth - very quickly - looking at some of the evidence supporting a benefit of one type compared to another.

Meeting the load

Physiological control systems - hypertrophy and atrophy

Running a 'fast' marathon requires a body prepared for the stresses that arise during the race. The order and extent of the stresses depends upon the relative effort expended by the runner. Training is usually considered to be the best way of adapting the physiological systems such that they do not fail dramatically during the race. The degree to which different elements of training prepare the body is often considered to be highly individualistic - Everyone is different - is a common refrain. The underlying idea being that what makes one person fast will not necessarily work for another.

A test (n=1) of weight loss during running

There are reasons why different runners might best adopt 'slightly' different pacing strategies (profiles), even in flat corner-free road marathons, to get their optimal times - if it is critical to maintain a constant metabolic rate in skeletal muscle. One of the reasons has to do with physics, the other physiology. I thought I would try and calculate what that optimal pacing profile (for that 'mythical' flat wind-free cool road marathon) might look like for me. Just how much of a change in pace should I be aiming for if I were to make the very best use of my skeletal muscle carbohydrate stores? [The real world importance of this may be limited since it is possible that I am not limited by my carbohydrate reserves at the pace I can sustain and other runners may fail to make the best of their reserves because they start too quickly in the first place.]

The problem with using race predictors for choosing marathon race pace.

Is there a problem with using race predictors for marathon pace setting?

Often marathon runners use race predictors to help set their marathon pace - but, there is a real problem with that approach. I thought it might be interesting to give a few real world examples from people at opposite ends of the performance spectrum to illustrate the problem (and one in the middle). This is not a full scientific analysis - and you could accuse me of cherry picking my data. But, this is real data from runners who I know were making serious attempts to produce their best performance. These are runners I respect and have given their all in pursuit of a good marathon time. Of course there are plenty of examples of where race pace predictors work reasonably well - and I will try and do a statistical analysis of just how well they work for different types of runners at a later date. But, for now I want to show that care needs to be taken when extrapolating from shorter distance race performance to longer distances. What limits performance at 10km is not necessarily what limits performance in a marathon. This is not just a minor problem.