TABLE 2.

Oxidation stress response with placebo (PLA), low-dosage caffeinated energy drink (Low ED) group and high-dosage caffeinated energy drink (High ED) group before and after participation in a sprint triathlon. *Significant difference at p < 0.05.

	PLA	Low ED	High ED	Main effect		p vs. L	p vs. H	L vs. H
	Mean ± SE			F	p	p-value (Cohen’s d)
	SOD (U/ml)
Pre	2.1 ± 0.3	2.1 ± 0.3	2.1 ± 0.3	0.0	0.96
Post	1.8 ± 0.2	1.7 ± 0.3	1.6 ± 0.3	4.1	0.03*	p = 0.12	p = 0.02*(0.2)	p = 0.02*(0.2)
p-value	p = 0.01*	p = 0.01*	p = 0.00*
	Catalase (nmol/min/ml)
Pre	46.8 ± 3.8	44.8 ± 1.8	49.0 ± 7.3	0.19	0.83
Post	68.6 ± 4.2	63.5 ± 3.9	63.7 ± 2.7	1.7	0.20
p-value	p = 0.00*	p = 0.00*	p = 0.03*
	TBARS (μM)
Pre	7.2 ± 1.6	10.2 ± 1.6	13.0 ± 3.8	1.5	0.25
Post	13.2 ± 4	5.9 ± 0.6	6.0 ± 0.8	3.8	0.04*	p = 0.04*(0.8)	p = 0.03*(0.7)	p = 0.46
p-value	p = 0.07	p = 0.02*	p = 0.03*
	GSH (μg/ml)
Pre	11.8 ± 1.4	12.1 ± 1.1	13.2 ± 1.7	0.44	0.65
Post	13.4 ± 1.6	13.8 ± 1.9	13.0 ± 2.3	0.14	0.87
p-value	p = 0.19	p = 0.13	p = 0.45
	GSSG (μg/ml)
Pre	181.3 ± 20.3	194.3 ± 13.4	184.1 ± 10.5	0.3	0.76
Post	184.5 ± 18.7	183.1 ± 12.2	186.5 ± 13.1	0.0	0.98
p-value	p = 0.43	p = 0.20	p = 0.44
	GSH/GSSG(μg/ml)
Pre	0.08 ± 0.02	0.06 ± 0.01	0.07 ± 0.01	0.7	0.50
Post	0.08 ± 0.01	0.08 ± 0.01	0.07 ± 0.01	0.3	0.76
p-value	p = 0.45	p = 0.10	p = 0.48