Research review: Which conditioning protocol for an ultra event?

What strength and conditioning protocols can enhance ultramarathon performance?Sports Performance Bulletin looks at some new evidence

Athletes undertaking their first ultra-running event are taking something of a leap into the unknown. In nearly all cases, the athlete will be pushing the boundaries of their endurance further than ever before. Naturally, much of the preparation for such an event is focussed on building up base endurance by increasing running mileage both in terms of maximum run length and accumulated weekly running distance. Thanks to the ‘specificity of training’ principle (train in a way that most closely replicates the demand of your event), this makes perfect sense.

Preparing for the big one

Another aspect of preparation that needs to be considered is injury prevention; the high training volumes required for ultra running and the demands of the event increase the risk of an overuse injury. This may involve a generalized program of strength and conditioning to help athletes build more ‘resilience against injury (see this article for a more in-depth discussion of this topic). Then there’s the physiological challenge of the event itself. High levels of heat, humidity or cold can place high demands on the body homeostasis systems, increasing the risk of heat stroke, dehydration, kidney injury, or (in the case of cold) hypothermia. These challenges require that prevention strategies and planning are put in place to help ensure the athletes can complete the event and complete it safely (see this article by John Shepherd for a detailed treatise into what this involves).

Performance and data

Injury prevention and strategies to ensure completion on the day are important for ultramarathon success. But what is less understood is what kind of strength and conditioning protocols might actually enhance ultra-running performance on the day, enabling an athlete to complete the event in a faster time. A major reason for the paucity of data on this topic is that it’s harder to collect; there are far fewer ultra-running events with far fewer competitors compared to say 10km and half/full marathon, which means fewer subjects to gather data from. Also, it’s much more difficult (mainly for logistical and ethical reasons) to perform lab studies on athletes running very large distances (often over 50 miles). For all these reasons, much of the training advice for ultra athletes has  traditionally been based on what has worked well for other athletes in the past, rather than hardcore scientific data.

New research

In the light of the above, a new study on ultra runners competing in a 107km (65-mile) mountain marathon by a group of Spanish scientists at the University of Valencia provides a valuable insight into the kind of strength and conditioning measures that might actually enhance ultra-running performance(1). In this study, researchers compared various aspects of lower-limb strength and respiratory parameters in 47 ultra runners, and sought to discover how they appeared to influence performance in the mountain marathon. Two to four weeks before the race, the following tests were carried out:

  • A squat jump test to assess lower-limb explosive strength
  • An ankle rebound test to assess ankle reactive strength
  • An isometric maximal voluntary contraction (IMVC – strength test) in a half-squat position.

The respiratory assessments included pulmonary function testing and the measurement of maximal inspiratory pressure (forced vital capacity, forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF).

The findings

The male athletes’ average finish time was 20hrs 43mins, while females athletes’ average finish time was 22hrs 20mins. Those average finish times represented 174% of men’s winning time and 157% of women’s winning time, respectively. In terms of performance spread, they ranked from 13th to 395th place (of 397 finishers) in the male category, and from 7th to 32nd place (of 47 finishers) in the female category – ie the athletes’ performances spanned a wide range of abilities. When the data was analyzed, the key finding was that the athletes’ race times were very significantly associated with their ankle rebound test performance, their isometric half-squat strength levels and the maximum inspiratory pressure they were able to achieve in the lung function tests.

When explaining their findings, the researchers pointed out that previous research has established a relationship between isometric strength and mountain marathon performance, and that isometric strength training performed at a long muscle length is highly recommended to improve strength at biomechanically disadvantaged joint positions (ie as the ones that mountain runners sustain during downhill sections)(2). As for the ankle rebound test correlation, the researchers explained that leg stiffness improvement has been correlated with an increase in running economy(3), and that higher levels of ankle reactivity are associated with better downhill running performance – an important component of most ultra events(4).

Implications for athletes

Although more research is needed, these findings suggest that isometric squat strength and ankle rebound strength are of importance for athletes seeking to maximize ultra-event performance. The scientists in this study proposed that strength training and assessment protocols in athletes competing in those races should focus on the above-mentioned strength-related capacities. They also noted that relationship between lower levels of ankle reactive strength and poorer performance was particularly noticeable among the female athlete, so training strategies aimed at improving this strength-related capacity seem especially pertinent among women. See this article for more information on ankle reactive strength exercises (and more).

Another recommendation was that ultra runners should consider performing inspiratory muscle training with the aid of a pressure threshold device (eg PowerBreathe), either in isolation or integrated into core-training workouts. Using data from previous research, the optimum recommendation is to start with a protocol of 30 resisted breaths, twice daily, at an intensity corresponding to the 50% of maximum inspiratory pressure(5,6). Those new to inspiratory training are recommended to read this article by Professor Alison McConnell.


  1. Sports (Basel). 2020 Oct 14;8(10):E134
  2. Int. J. Sports Med. 2019, 40, 363–375
  3. Graefe’s Arch. Clin. Exp. Ophthalmol. 2013, 113, 1605–1615
  4. J. Sci. Med. Sport 2020. [Google Scholar] [CrossRef]
  5. Phys. Ther. Sport 2018, 34, 92–104
  6. Phys. Ther. Sport 2016, 17, 76–86

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