Effects of wearing a full body compression garment during recovery from an ultra-trail race.

In sport disciplines with high levels of muscle damage such as an ultra-trail competition, full body compression garments (FBCG) may have an ergogenic effect during the recovery process. The aim of the study was to assess the influence of FBCG worn for 24 h immediately after a 107-km ultra-trail on delayed onset muscle soreness (DOMS), muscle damage, inflammatory and renal response. Thirty-two athletes (19 males and 13 females; VO2peak: 54.1 ± 5.2 ml O2/kg/min) participated in the study. The following blood markers were analysed before, immediately after, at 24 and 48 h post-race: lactate dehydrogenase, creatine kinase, C-reactive protein and creatinine. The glomerular filtration rate was also calculated. Delayed onset muscle soreness was evaluated before, immediately after and at 24 h post-race. On arrival at the finishing line, athletes were randomised into one of two recovery groups (FBCG and control group). The results showed that wearing FBCG did not influence the evolution of any of the blood markers up to 48 h after the race (p > .05). However, FBCG group presented a lower increase in posterior leg DOMS (11.0 ± 46.2% vs 112.3 ± 170.4%, p = .03, d = 0.8). Therefore, although FBCG is not useful for reducing muscle damage and inflammatory response after an ultra-trail race, its use may still be recommended as a recovery method to reduce muscle soreness.Trial registration: ClinicalTrials.gov identifier: NCT03990259.

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

The study aimed at assessing the acute physiological effects of running a 65-km vs a 107-km mountain ultramarathon. Nineteen athletes (15 males and 4 females) from the shorter race and forty three athletes (26 males and 17 females) from the longer race were enrolled. Body weight, respiratory and lower limb strength were assessed before and after the race. Blood samples were obtained before, after and 24-h post-race. Body weight loss did not differ between races. A decrease in squat jump height (p<0.01; d = 1.4), forced vital capacity (p<0.01; d = 0.5), forced expiratory volume in 1 s (p<0.01; d = 0.6), peak inspiratory flow (p<0.01; d = 0.6) and maximal inspiratory pressure (p<0.01; d = 0.8) was observed after the longer race; while, after the shorter race only maximal inspiratory pressure declined (p<0.01; d = 0.5). Greater post-race concentrations of creatine kinase (p<0.01; d = 0.9) and C-reactive protein (p<0.01; d = 2.3) were observed following the longer race, while high-sensitivity cardiac troponin was higher after the shorter race (p<0.01; d = 0.3). Sodium decreased post-competition only after the shorter race (p = 0.02; d = 0.6), while creatinine increased only following the longer race (p<0.01; d = 1.5). In both groups, glomerular filtration rate declined at post-race (longer race: p<0.01, d = 2.1; shorter race: p = 0.01, d = 1.4) and returned to baseline values at 24 h post-race. In summary, expiratory and lower-limb fatigue, and muscle damage and inflammatory response were greater following the longer race; while a higher release of cardiac troponins was observed after the shorter race. The alteration and restoration of renal function was similar after either race.

Initiating running barefoot: Effects on muscle activation and impact accelerations in habitually rearfoot shod runners.

Runners tend to shift from a rearfoot to a forefoot strike pattern when running barefoot. However, it is unclear how the first attempts at running barefoot affect habitually rearfoot shod runners. Due to the inconsistency of their recently adopted barefoot technique, a number of new barefoot-related running injuries are emerging among novice barefoot runners. The aim of this study was therefore to analyse the influence of three running conditions (natural barefoot [BF], barefoot with a forced rearfoot strike [BRS], and shod [SH]) on muscle activity and impact accelerations in habitually rearfoot shod runners. Twenty-two participants ran at 60% of their maximal aerobic speed while foot strike, tibial and head impact accelerations, and tibialis anterior (TA), peroneus longus (PL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscle activity were registered. Only 68% of the runners adopted a non-rearfoot strike pattern during BF. Running BF led to a reduction of TA activity as well as to an increase of GL and GM activity compared to BRS and SH. Furthermore, BRS increased tibial peak acceleration, tibial magnitude and tibial acceleration rate compared to SH and BF. In conclusion, 32% of our runners showed a rearfoot strike pattern at the first attempts at running barefoot, which corresponds to a running style (BRS) that led to increased muscle activation and impact accelerations and thereby to a potentially higher risk of injury compared to running shod.