Table 1. The results of the categorical comparison between study groups in terms of heart tissue levels of energy charge, AMP, ADP and ATP.

Parameters	Study groups			Comparisons
	Control (n = 10)	Acute exercise (n = 10)	Melatonin (n = 10)	Control/acute exercise	Control/melatonin	Acute exercise/melatonin
AMP (μmol/g)	-	-	-	-	-	-
ADP (μmol/g)	13.41 ± 8.3	7.61 ± 30	13.78 ± 4.5	p > 0.05	p > 0.05	p < 0.05
ATP (μmol/g)	0.52 ± 0.30	0.32 ± 0.20	0.62 ± 0.23	p > 0.05	p > 0.05	p < 0.05
Energy charge	0.86 ± 0.42	0.62 ± 0.35	1.55 ± 0.59	p > 0.05	p < 0.05	p < 0.001

AMP, adenosine monophosphate; ADP, adenosine diphosphate; ATP, adenosine triphosphate; SD, standard deviation.

Data are expressed as mean ± SD for continuous variables.