Which energy system primarily produces energy for an individual running for 30 minutes?

The oxidative energy system is the primary source of energy for an individual running for 30 minutes due to its ability to efficiently produce ATP through the breakdown of carbohydrates and fats in the presence of oxygen. This energy system becomes dominant during prolonged, moderate-intensity activities, such as a steady run.

When the body is engaged in an aerobic exercise, it relies on oxygen to metabolize nutrients, which leads to sustained energy production. In contrast, during shorter, high-intensity efforts, such as a sprint, the ATP-CP (adenosine triphosphate - creatine phosphate) and non-oxidative systems (also known as anaerobic systems) might be more relevant, but they are not suitable for an endurance activity lasting 30 minutes due to their limited capacity and quick depletion of energy resources.

The lactate system, while involved in higher intensity activities, depends on anaerobic glycolysis and would not be the primary energy producer during a longer duration of exercise that relies significantly on aerobic metabolism. Thus, the oxidative system is the most appropriate choice for sustained energy production in endurance activities, such as running for 30 minutes.