Is glycolysis reduction or oxidation?

Glycolysis involves both oxidation and reduction reactions. During the oxidation of glyceraldehyde-3-phosphate (G3P) to 1,3-bisphosphoglycerate, G3P is oxidized (loses electrons), and NAD+ is reduced (gains electrons) to form NADH. This is the key redox reaction in glycolysis. In general, oxidation reactions release energy, while reduction reactions store energy in molecules like NADH.