Morning-to-evening difference of biomarkers of muscle injury and antioxidant status in young trained soccer players

Abstract

The aim of this study was (i) to evaluate whether homocysteine (Hcy), total antioxidant status (TAS), and biological markers of muscle injury would be affected by time-of-day (TOD) in well-trained soccer players. In a counterbalanced order, 20 soccer players participated on two different occasions between 07:00 and 08:30 h and between 17:00 and 18:30 h. Fasting blood samples were collected from a forearm vein during each session. The results showed that the values of white blood cells (WBC), neutrophils (NE), lymphocytes (LY), and monocytes (MO) are higher in the evening than the morning. Although there was no TOD effect on blood lactate (Lac) levels, significant difference was observed for urea (URE), creatinine (CRE), and blood glucose (GLC) indicating higher evening levels. Moreover, the results also showed diurnal variations of core temperature, resting Hcy levels, and all biological markers of muscle injury [i.e., aspartate aminotransferase (ASAT), creatine kinase (CK), lactate dehydrogenase (LDH)].These parameters were lowest in the morning and tended to rise throughout the day. Furthermore, biomarkers of antioxidant status [i.e., TAS, uric acid (UA), and total bilirubin (TBIL)] displayed a significant effect of TOD with higher morning levels. In conclusion, the present study confirms the diurnal variations of Hcy, selected biological markers of cellular damage, and antioxidant status in young trained soccer players. Our finding suggests the fact that muscle damage and inflammation could be more important in the evening and that antioxidant status is more efficient in the morning.

High Intensity Exercise Affects Diurnal Variation of Some Biological Markers in Trained Subjects

“…These fi ndings are in agreement with previous studies that have identifi ed peak times for these variables to be situated between 18:00 and 24:00 h in healthy sedentary subjects [ 14 , 19 ] . We recently found similar results in trained subjects [ 11 ] . After the Wingate test, the present hematological results showed increases of RBC, HCT and WBC (as well as their subpopulations) at both times of testing.…”

Morning melatonin ingestion and diurnal variation of short-term maximal performances in soccer players

“…It is well established that athletic performances display a diurnal pattern with higher values measured in the late afternoon and lower measures observed in the early morning (12). Likewise, it has been shown that soccer players perform at an optimum between 16:00 h and 20:00 h when soccerspecific skills and measures of physical performance are at their peak (18).…”

“…MEL, often considered as a chronobiotic (12), was initially investigated in terms of its role in endocrine physiology regulating circadian and sometimes seasonal rhythms (22). Moreover, it has been shown that exogenous MEL can improve sleep quality and alleviate jet lag symptoms after transmeridian travels (5).…”

Recent Evidence on the Impact of Ramadan Diurnal Intermittent Fasting, Mealtime, and Circadian Rhythm on Cardiometabolic Risk: A Review

“…As with the inflammatory biomarkers, measured biomarkers of oxidative stress are affected by the above discussed lifestyle changes that accompany Ramadan (89)(90)(91)(92)(93)(94)(95)(96), and the relationship with the timing of the blood samples to mealtime (90). Previously discussed studies collected only a single early morning blood sample.…”

“…Previously discussed studies collected only a single early morning blood sample. Oxidant levels could have been affected by the sample collection time as well as by the interaction between sample collection time and mealtime (91,93). The blood sample collection time of oxidant or anti-oxidant activity may affect the measured levels.…”