Acute melatonin administration enhances aerobic tolerance: an analysis of biochemical and hematological parameters

Abstract

This study is aimed at testing the acute melatonin administration (oral; 6 mg) on aerobic tolerance at cycloergometer and analyzing the consequences on biochemical and hematological parameters. Methods: The maximal aerobic capacity intensity (iMAC) at cycloergometer of eleven male healthy men (24.18±3.92 years-old; 87.07±12.48 kg; 1.82±0.05 m; 26.18±3.63 kg/m 2 ; and 16.28±5.77 % of fat) was individually determined and used to perform a time to exhaustion (tlim) trial of 30 minutes after melatonin or placebo administration. We observed 48-72h interval between tests, performed in a double-blind experiment design. In order to determine hematological and biochemical parameters we collected venous blood samples before and after tlim. Statistical significance was set at 5%. Results: The intensity and the lactatemia corresponding to the maximal aerobic capacity were 120.88±18.78 W and 3.32±1.03 mmol.L-1 , respectively. The tlim with placebo (33.94±15.26 min, confidence interval = 24.92-42.95) was significantly lower than the tlim with melatonin (41.94±17.22 min; CI = 31.76-52.12; p = 0.03; 19.06%; effect size = 0.49). All of the 21 analyzed blood physiological variables resulted in no significant variation after tlim when placebo was compared to melatonin, except for total sera cholesterol (lower after exercise with melatonin). Conclusion: Acute melatonin administration enhanced aerobic tolerance at iMAC in 19% at cycloergometer; however, the biochemical and hematological variables assessed were not significantly modulated.

Effect of melatonin ingestion on physical performance, metabolic responses, and recovery after an intermittent training session

“…Moreover, morning (i.e., 07:30 a.m.) ingestion of MEL (5 mg) decreased only morning (i.e., 08:00 a.m.) short-term maximal performances but not performances achieved at 12:00 a.m. and 4:00 p.m. (20). However, more recent studies (8,12) have shown that MEL ingestion improved short-term and aerobic performances. In addition, another study in rats (9) found that MEL ameliorates aerobic performance during a swimming exercise until exhaustion.…”

“…MEL has a protective effect on muscle and hepatic glycogen stores by inhibiting their depletion (23,31,37) and also it improves lipid metabolism (28). Furthermore, exogenous MEL ingestion has improved short-term and aerobic performances (8,12). From these observations, MEL seems a potential reasonable ergogenic aid with a considerable protective effect from muscle fatigue after intense exercise.…”

Exercise-induced oxidative stress and melatonin supplementation: current evidence

“… : 70%, 90%) Significantly increased MT level, TAC and GPx levels, decreased DNA damage in MT-treated group vs placebo group after 2-week exercise MT treatment strengthens antioxidant state of athletes and protects DNA from damage caused by high intensity exercise Ziaadini et al 2017 [ 118 ] Two groups of sedentary women: involved in exercise training and treated with MT ( n = 10) and only training ( n = 10), mean age: 24.2 ± 1.03 and 23.4 ± 1.83 years, respectively 3 mg/day MT supplementation before exercise training 8-week (3 days/week) exercise training of increasing intensity and volume from 60 to 80% HRmax through 15 to 45 min Significantly increased levels of MDA after long-lasting aerobic exercise training. Suppression of post-exercise increased MDA in the exercising and supplemented group Supplementation with MT may decrease ROS levels, thus improve lipid profile Beck et al 2018 [ 119 ] 11 males moderately active, mean age: 24.18 ± 3.92 years MT (6 mg) or placebo ingestion 30 min before exercise Exercise on cycloergometer with initial workloads of 75 W and increments of 15 W each 3 min till exhaustion Maximal aerobic capacity 120.88 ± 18.78 W A time to exhaustion significantly lower in placebo group compared to that with MT administered by approximately 19% MT supplementation enhanced aerobic tolerance but was without effect on the biochemical and hematological parameters Brandenberger et al 2018 [ 120 ] Ten cyclists long-distance training, mean age 25.0 ± 4.0 years 5 mg MT administered 15 min before time trial. Controls: placebo 15 min before time trial 32.2 km cycling time trial performance at 62.7 ± 6.8 (mL kg −1 min −1 ) on ergometer.…”

“…The data indicate MT intake reduced the markers of OS and inflammation in athletes engaging in severe high-intensity exercise, independently of timing of MT intake. Only three [ 119 – 121 ] of 11 presented experimental studies examined the MT influence on redox status followed moderate-intensity exercise. These authors found no effect of the hormone (5–6 mg doses) on biochemical and hematological parameters.…”

“…Three of 11 presented studies [ 119 , 120 , 125 ] also examined effects of MT supplementation on exercise performance, finding its improvement in the two reported studies [ 119 , 125 ]. In turn, a study by Souissi et al [ 121 ] tested the effect of MT supplementation on inflammation induced by exercise at 60% , i.e., the lowest value of the maximum rate of O 2 consumption for exercise classified as high intensity.…”