In terms of blood pressure increase, which activity would be expected to have the least effect?

Aerobic exercise at 60% of VO2max is considered to have the least effect on blood pressure increase primarily because this intensity falls within the moderate exercise range, which is associated with lower cardiovascular responses compared to higher intensity or resistance activities. During moderate aerobic exercise, the body primarily utilizes oxidative pathways for energy production, allowing it to manage energy demands while keeping heart rate and blood pressure within a more moderate range.

Additionally, steady-state aerobic activities tend to promote vasodilation, which helps blood flow and can potentially lower blood pressure in the long term. In contrast, activities like circuit training, heavy resistance exercises, and high-intensity interval sprints can lead to considerable increases in intrathoracic pressure and subsequently elevate blood pressure during the lifting or sprinting efforts, as they require greater maximal exertion and trigger different physiological responses including the Valsalva maneuver in strength training. These responses are more pronounced at higher percentages of one-repetition maximum or during high-intensity activities, explaining why they would cause a larger increase in blood pressure compared to moderate aerobic exercise.