What are the Limiting Factors During an Ultra‐Marathon? A Systematic Review of the Scientific Literature

Abstract

This review aimed to analyse factors that limited performance in ultra-marathons and mountain ultra-marathons. A literature search in one database (PubMed) was conducted in February 2019. Quality of information of the articles was evaluated using the Oxford´s level of evidence and the Physiotherapy Evidence Database (PEDro) scale. The search strategy yielded 111 total citations from which 23 met the inclusion criteria. Twenty one of the 23 included studies had a level of evidence 2b (individual cohort study), while the 2 remaining studies had a level of evidence of 5 (expert opinion). Also, the mean score in the PEDro scale was 3.65 ± 1.61, with values ranging from 0 to 7. Participants were characterised as experienced or well-trained athletes in all of the studies. The total number of participants was 1002 (893 men, 86 women and 23 unknown). The findings of this review suggest that fatigue in ultra-endurance events is a multifactorial phenomenon that includes physiological, neuromuscular, biomechanical and cognitive factors. Improved exercise performance during ultra-endurance events seems to be related to higher VO2max values and maximal aerobic speed (especially during submaximal efforts sustained over a long time), lower oxygen cost of transport and greater running experience.

Influence of Psychological Factors on the Success of the Ultra-Trail Runner

“…Consequently, interest in researching decisive factors to performance in these types of trials has become the focus of multiple research groups around the world. Ultra-endurance races are a multifactorial event that include physiological, neuromuscular, biomechanical, and psychological factors [ 3 ]. Multiple studies have focused on analyzing the physiological variables for improving performance in ultra-marathons [ 4 ], yet a lack of knowledge still abounds regarding the psychological factors that are unique to these runners, despite an increase in studies in recent years due to the rising popularity of these types of races [ 5 , 6 ].…”

Effects of Ultratrail Running on Neuromuscular Function, Muscle Damage and Hydration Status. Differences According to Training Level

“…Ultratrail racing is performed on routes with adverse orography. Its distance exceeds that of marathons [ 2 , 3 ], and ranges between 80 km and 300 km [ 4 ]. The fact that ultratrail runners face unstable environmental and weather conditions for long periods of time, and constant changes in the topography of land and altitude [ 4 ], with considerable positive and negative slopes [ 5 ], is also emphasized.…”

“…Ultratrail races are multifactorial events that include physiological, neuromuscular, biomechanical and psychological variables [ 2 ]. Depending on exertion while running these races, research works indicate that according to ventilator thresholds (VT), in physiological terms these races place mean training intensities at 85.7% for zone I (<VT1), 13.9% for zone II (VT1–VT2) and 0.4% for zone III (>VT2) [ 11 ].…”

“…In ultratrail endurance races, optimum performance might depend on high maximal oxygen consumption (VO 2max ) levels, high VO 2max fraction utilization percentages and low oxygen transport cost [ 2 ]. Along these lines, it has been demonstrated that maximum aerobic power can be a limiting factor to running on positive slopes [ 17 ], which are usual for ultratrail routes.…”

Inspiratory and Lower-Limb Strength Importance in Mountain Ultramarathon Running. Sex Differences and Relationship with Performance

“…Inspiratory muscle training using linear workload devices is accessible to athletes [ 13 ] and it constitutes an effective tool to improve endurance-sports performance [ 13 , 14 , 15 ]. Overall, further studies are warranted to resolve whether the limiting factors in ultra-endurance events are similar to those described in shorter distances [ 16 ], as well as studies comparing performance factors in male and female athletes competing in ultramarathon races [ 17 ].…”