Current public health guidelines recommend that adults accumulate 150–300 minutes per week of moderate-intensity physical activity (the intensity equivalent to walking at casual-to-brisk pace) or 75–150 minutes per week of vigorous-intensity physical activity (the intensity equivalent to jogging or running). “But it’s important to note that the benefits of exercise are dose dependent, with the biggest benefits coming from just moving out of the couch-potato zone to doing at least some moderate-intensity activity,” Gaesser says. “It’s also important to emphasize that physical activity can be accumulated throughout the day. For example, multiple short walks during the day (even as short as two to ten minutes each) are just as beneficial as one long walk for health benefits.”
In the review, the authors cite recent research focused on the magnitude of mortality risk reduction associated with weight loss compared to that associated with an increase in physical activity or cardiorespiratory fitness. The risk reduction associated with increasing fitness and physical activity was consistently greater than that associated with intentional weight loss. They also looked at the magnitude of reduction in the risk markers of cardiovascular disease that are associated with either weight loss or increased physical activity. They used meta-analyses from several studies done over a range of time periods and across a broad geographical area. “Science has generally supported the main points proposed in Big Fat Lies, a book on this topic that I first published in 1996,” Gaesser notes.
The researchers acknowledge limitations in the existing body of research, including the fact that this field is heavily reliant on epidemiological studies that do not definitively establish cause and effect, and note that only large, randomized, controlled clinical trials can fully examine the outcomes of using a fitness-focused approach to optimize cardiometabolic mortality risk in people who are obese. “Collectively, however, these epidemiological studies demonstrate strong and consistent associations, and this is why meta-analyses can be useful,” Angadi says. “In the case of physical activity and fitness, the epidemiological evidence is supported by a large body of experimental studies and randomized controlled trials that have established plausible mechanisms for the consistent findings in epidemiological studies.”
The research was published in the journal iScience.
Source: Cell Press