Reduction of run training volume improves triathlon results

The aforementioned title is sadly just a big mental shortcut, so some readers may be a little bit disappointed because nothing is free – in this case the “price” was a very high intensity. Scientists from two Spanish universities decided to check how a 5-week 3-time reduction of run training volume would influence the results of triathlon runners.

On the one hand considerable volumes of run training may increase the overload injury risk, but on the other – there is a set of common benefits arising from high-intensity interval training (HIIT). In the study 16 triathlon runners took part. None of them had rested on HIIT in their preparations beforehand. Two groups were chosen at random – one group continued their previous training (average run volume about 34km/week), while the second group started doing high-intensity interval training, yet the volume was reduced to about 10km/week. Swimming and cycling trainings remained the same in both groups. They put forward a hypothesis that HIIT group would improve their results more substantially than the control group.

Run trainings in the experimental group involved solely sprints repetitions at distances from 100 to about 400 meters, at the speed exceeding the maximum consumption of oxygen speed (100-130% VVO2max), and (in weeks 3-5) 30-second sprints at top speed (4 or 6 x 30s. x 3min.).

Before and after intervention, participants’ results were checked on the basis of the simulation of the triathlon sprint distance (750m of swimming, 20 km of cycling and 5 km of running). During such simulations, pulse, RPE (rate of perceived exertion) and lactate level in blood (1 minute after the end) were monitored. Change time was excluded from the record.

Additionally, before and after the training intervention, “counter-jump” and half squat jump were checked in both groups to show neuro-muscle adaptation results.

Fig. 1.
Triathlon events time at the sprint distance in both groups before (black posts) and after (grey posts) a 5-week intervention.
In the experimental group the swimming time dropped by 3%, while the run distance – by 4%. Times in the control group remained the same.

Fig 2.
Counter-jump height in the experimental group (A) and control group (B) before intervention (black lines) and after (grey lines) was measured separately and during the simulated triathlon, after the end of every event. The experimental group improved this parameter by over 9%, whereas the control group kept the same parameter (measured after triathlon even declined by 3%).

We can conclude that neuro-muscle capabilities significantly improved. Performance in simulated competition after a 5-week change of run training into high-intensity interval training with reduced volume improved as well. Besides, no substantial differences in the organism physiological response (HR, lactate) were identified. The same applies to rate of perceived exertion (RPE) between groups  before and after intervention, which suggests an improvement of effort economics in the experimental group after training intervention (ability to do better in the triathlon with the same physiological cost). A precise mechanism for this state of affairs has not been fully explored yet.

„A HIIT-based running plan improves athletic performance by improving muscle power.”
Felipe García-Pinillos, Jose C. Cámara-Pérez, Víctor M. Soto Hermoso, Pedro Á. Latorre-Román

Journal of Strength and Conditioning Research
DOI: 10.1519/JSC.0000000000001473

When Spaniards do studies of this sort, it is advisable to consider and focus on their results because in the up-to-date ranking of ITU World Triathlon Series, as many as three Spanish athletes are in the top eight (including the leader Javier Gomez Noya).

The athletes who participated in the study were not top sportspersons (the proof is their times), and results, although interesting, give rise to further questions: – since five intervention weeks improved swimming and running results, does it mean that athletes should keep this kind of running training on a regular basis? Such a positive reaction may be a result of a new training stimulus. This is often a weakness of most studies during which a new training stimulus was introduced for a few-week period. In such situations we observe an initial irregular growth of performance, which is however followed by stagnation.

The effect of changed training intervention was checked in an artificial way (swimming in a pool, cycling on bike simulators) and with the use of “amateur” equipment (training simulator used to cycle Taxc Vortex entails a permissible error up to 10%) and at the 50% of triathlon distance. All of them could affect the reliability of results.

Authors claim that one of the reasons for using this type of training was reduction of injury risk arising from large volumes of running training. However, sprint training, despite being less intensive, is not devoid of injury risk, particularly among persons who did not use it on a regular basis.

Oprac. Mariusz Goliński, Rehasport Clinic Motor Skills Trainer