Study links 560-610 minutes of weekly moderate-to-vigorous exercise to major reductions in heart attack and stroke risk

Adults may need substantially more weekly exercise than current public health guidelines recommend to achieve major reductions in the risk of heart attack, stroke and other cardiovascular events, according to an observational study published in the British Journal of Sports Medicine.

Researchers from Macao Polytechnic University analyzed data from 17,088 UK Biobank participants (average age 57; 56% female; 96% white) enrolled between 2013 and 2015. Participants wore wrist devices for seven consecutive days to measure moderate-to-vigorous physical activity (MVPA) and completed a cycling test to estimate cardiorespiratory fitness via VO2 max. The analysis adjusted for factors including smoking, alcohol use, diet, body mass index, resting heart rate and blood pressure (BMJ Group).

Over a median follow-up of about 7.8–7.85 years, 1,233 incident cardiovascular events occurred, including 874 cases of atrial fibrillation, 156 myocardial infarctions, 111 heart failure cases and 92 strokes (ScienceDaily; British Journal of Sports Medicine abstract).

Meeting the widely recommended minimum of 150 minutes of MVPA per week—activities such as brisk walking, running or cycling—was associated with a modest 8–9% reduction in cardiovascular risk. This association held similarly across fitness levels (Healthline; The Guardian).

Substantial protection, defined by the researchers as a greater than 30% risk reduction, was linked to 560–610 minutes of MVPA per week—roughly three to four times the current guideline and equivalent to about 9–10 hours. Only 12% of study participants reached this level (BMJ Group; Medical News Today).

Fitness level influenced the volume needed. People with the lowest cardiorespiratory fitness required approximately 30–50 additional minutes per week compared with the fittest participants for equivalent benefits. For a 20% risk reduction, those at lowest fitness needed about 370 minutes weekly versus 340 minutes for those at highest fitness (ScienceDaily; The Guardian).

The study also used Mendelian randomisation analyses, finding some genetic evidence supporting a protective role for higher cardiorespiratory fitness against heart failure, though evidence for physical activity traits was weaker (British Journal of Sports Medicine abstract).

As an observational study, it cannot prove causation. Limitations noted by the authors include that participants may have been healthier and fitter than the general population, fitness was estimated rather than directly measured, and the analysis did not fully assess sedentary time or lower-intensity activity (BMJ Group).

The researchers concluded that current guidelines offer a robust universal minimum for basic cardiovascular protection but that future guidance may need to differentiate this from higher volumes associated with optimal risk reduction, potentially incorporating personalized targets based on fitness level. “Future guidelines may need to differentiate between the minimal moderate to vigorous exercise volume required for a basic safety margin and the substantially higher volumes necessary for optimal cardiovascular risk reduction,” they wrote (ScienceDaily).

Current recommendations from bodies such as the American Heart Association and World Health Organization advise at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic activity weekly for adults, with additional benefits noted at higher volumes up to 300 minutes (American Heart Association).