Body Composition Changes During a 24-h Winter Mountain Running Race Under Extremely Cold Conditions

Abstract

Background: To date, no study has focused on body composition characteristics and on parameters associated with skeletal muscle damage and renal function in runners participating in a 24-h winter race held under extremely cold environmental conditions (average temperature of -14.3°C). Methods: Anthropometric characteristics, plasma urea (PU), plasma creatinine (Pcr), creatine kinase (CK), plasma volume (PV) and total body water (TBW) were assessed pre- and post-race in 20 finishers (14 men and 6 women). Results: In male runners, body mass (BM) ( p = 0.003) and body fat (BF) ( p = 0.001) decreased [-1.1 kg (-1.4%) and -1.1 kg (-13.4%), respectively]; skeletal muscle mass (SM) and TBW remained stable ( p > 0.05). In female runners, BF decreased ( p = 0.036) [-1.3 kg (-7.8%)] while BM, SM and TBW remained stable ( p > 0.05). The change (Δ) in BM was not related to Δ BF; however, Δ BM was related to Δ SM [ r = 0.58, p = 0.007] and Δ TBW ( r = 0.59, p = 0.007). Δ SM correlated with Δ TBW ( r = 0.51, p = 0.021). Moreover, Δ BF was negatively associated with Δ SM ( r = -0.65, p = 0.002). PV ( p < 0.001), CK ( p < 0.001), Pcr ( p = 0.004) and PU ( p < 0.001) increased and creatinine clearance (CrCl) decreased ( p = 0.002). The decrease in BM was negatively related to the increase in CK ( r = -0.71, p < 0.001). Δ Pcr was positively related to Δ PU ( r = 0.64, p = 0.002). The decrease in CrCl was negatively associated with the increase in both PU ( r = -0.72, p < 0.001) and CK ( r = -0.48, p = 0.032). Conclusion: The 24-h running race under extremely cold conditions led to a significant BF decrease, whereas SM and TBW remained stable in both males and females. Nevertheless, the increase in CK, Pcr and PU was related to the damage of SM with transient impaired renal function.

Peer Review #3 of "Creatinine is a biochemical marker for assessing how untrained people adapt to fitness training loads (v0.1)"

“…A similar increase in creatinine concentration in response to physical stress stimuli is primarily associated with structural damage of the working muscles and may subsequently lead to impaired renal function (e.g. Chlíbková, et al, 2019). Studying the nature of changes in the basal level of creatinine concentration we found out that this biochemical indicator increased in group B representatives due to accelerated growth of the body strength capabilities, circumference body size and, accordingly, muscle mass overall.…”

Peer Review #2 of "Creatinine is a biochemical marker for assessing how untrained people adapt to fitness training loads (v0.2)"

“…To ensure the effectiveness of biomedical control at all stages of training activity the leading specialists in physical education and biology (Chernozub, 2015;Cadegiani, et al, 2019;Chlíbková, et al, 2019) are in constant search for the most informative markers of assessing adaptation-compensatory responses to physical stress stimuli. Due to the constant increase in training loads, the body undergoes significant metabolic changes to ensure the necessary level of training.…”