Glycolysis and gluconeogenesis are both pathways the body utilizes for energy production. although both pathways employ common enzymes, they are not the reverse of one another. they are also not usually used simultaneously. which pathway(s) is(are) used during intense physical exercise?

Mainly, glycolysis is used in intense physical exercise to produce more pyruvate as a substrate for aerobic metabolism (as well as increased oxygen consumption). Intense physical exercise will also produce another byproduct of glycolysis which is lactate or lactic acid, which is then converted back to glucose through gluconeogenesis. So the answer is both glycolysis and gluconeogenesis work during intense physical activity.