Pulmonary and Respiratory Muscle Function in Response to Marathon and Ultra-Marathon Running: A Review

Abstract

The physiological demands of marathon and ultra-marathon running are substantial, affecting multiple body systems. There have been several reviews on the physiological contraindications of participation; nevertheless, the respiratory implications have received relatively little attention. This paper provides an up-to-date review of the literature pertaining to acute pulmonary and respiratory muscle responses to marathon and ultra-marathon running. Pulmonary function was most commonly assessed using spirometry, with infrequent use of techniques including single-breath rebreathe and whole-body plethysmography. All studies observed statistically significant post-race reductions in one-or-more metrics of pulmonary function, with or without evidence of airway obstruction. Nevertheless, an independent analysis revealed that post-race values rarely fell below the lower-limit of normal and are unlikely, therefore, to be clinically significant. This highlights the virtue of healthy baseline parameters prior to competition and, although speculative, there may be more potent clinical manifestations in individuals with below-average baseline function, or those with pre-existing respiratory disorders (e.g., asthma). Respiratory muscle fatigue was most commonly assessed indirectly using maximal static mouth-pressure manoeuvres, and respiratory muscle endurance via maximum voluntary ventilation (MVV 12 ). Objective nerve-stimulation data from one study, and others documenting the time-course of recovery, implicate peripheral neuromuscular factors as the mechanism underpinning such fatigue. Evidence of respiratory muscle fatigue was more prevalent following marathon compared to ultra-marathon, and might be a factor of work rate, and thus exercise ventilation, which is tempered during longer races. Potential implications of respiratory muscle fatigue on health and marathon/ultra-marathon performance have been discussed, and include a diminished postural stability that may increase the risk of injury when running on challenging terrain, and possible respiratory muscle fatigue-induced effects on locomotor limb blood flow. This review provides novel insights that might influence marathon/ultra-marathon preparation strategies, as well as inform medical best-practice of personnel supporting such events.

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

“…Notwithstanding, further studies are required to clarify whether MVV is associated with MUM performance. On the other hand, the significant association between MIP and race time reinforce previous suggestions about the importance of inspiratory muscle function in ultramarathon running [ 11 , 34 ]. Inspiratory muscle fatigue has been demonstrated to impair locomotor muscle performance because a larger fraction of total cardiac output is required by the respiratory muscles and a sympathetic vasoconstrictor response to working skeletal muscle is triggered through a respiratory muscle metaboreflex [ 35 , 36 ].…”

“…Inspiratory muscle fatigue has been demonstrated to impair locomotor muscle performance because a larger fraction of total cardiac output is required by the respiratory muscles and a sympathetic vasoconstrictor response to working skeletal muscle is triggered through a respiratory muscle metaboreflex [ 35 , 36 ]. At the same time, it has been proposed that inspiratory muscle strength is a critical determinant of the magnitude of inspiratory muscle fatigue during prolonged endurance exercise [ 34 , 35 ]. Therefore, although we cannot infer a causal relationship from a correlation, our results reinforce the pertinence of a specific inspiratory muscle training in MUM runners, as it has been advocated for other endurance sports (i.e., road running, rowing, cycling) [ 13 , 14 , 15 ].…”

“…Moreover, as respiratory muscles play an important role regarding trunk stability [ 37 , 39 , 40 ] and post-MUM reductions in static and dynamic postural control have been documented [ 41 , 42 ], a better muscle inspiratory capacity may minimize the risk of fall and improve ventilatory efficiency and running economy in the last segments of the races [ 10 , 11 , 34 , 43 ]. Indeed, regarding ventilatory efficiency, a recent study has observed that during downhill running, as compared with uphill running, the ventilation pattern becomes more superficial (greater respiratory frequency and lower tidal volume) [ 20 ]; so inspiratory muscle training could aid to improve the ventilatory pattern during the downhill sections of MUM.…”

Effect of mountain ultramarathon distance competition on biochemical variables, respiratory and lower-limb fatigue

“…However, MIP was significantly reduced following both races. These findings suggest that inspiratory muscle strength is more sensitive to fatigue subsequent to running a MUM, compared with expiratory pulmonary function [9,45]. Hence, the addition of specific MIP training into the daily routine of these athletes might improve their performance [46,47].…”

Acute effects of high-volume compared to low-volume resistance exercise on lung function

“…Such a hypothesis is based on training adaptation theories which suggest that an adequate training stimulus would result in the accumulation of fatigue, which in this case would be a reduction lung function, and upon recovery an improvement in performance (Cunanan et al, 2018). Diminished lung function has been observed following marathon and ultramarathon running (Tiller, 2019) and after a CrossFit (i.e., a form of high-intensity interval training) bout (Shaw et al, 2015). Furthermore, superior lung function performance has been observed in endurance athletes compared to strength and power athletes (Lazovic et al, 2015).…”