Consistency is key: Regular exercise important for weight loss

New research suggests that aside from increasing level of physical activity (PA) over time, greater regularity of exercise also promotes short-term weight loss.

“Indeed, our results suggest that the variability in PA level is an interesting additional parameter to be considered as a digital biomarker candidate when assessing the impact of PA on health,” the researchers said. “This work has shown that data from wearable devices are helpful for the digital phenotyping of large populations in real-life settings and also to suggest new metrics to characterize PA that could be easily replicated in future studies.”

Data were collected from 26,935 users of wearable activity trackers and digital scales to assess 6-month changes in weight and exercise patterns. Measurements during the first and sixth 30-day periods were obtained, and for each, the monthly mean for the daily number of steps was used as the measure of PA, while the coefficient of variation (CV) was used to assess exercise variability.

Multivariable linear regression analysis showed an inverse link between mean PA level and weight change. For instance, those who were low-active at baseline, characterized as taking 5,000–7,499 steps per day on average, saw a 0.21-kg (95 percent confidence interval [CI], –0.36 to –0.06) greater drop in weight than those who were classified as sedentary (<5,000 steps per day). [JMIR Mhealth Uhealth 2021;9:e25385]

The differences in weight change were 0.52 (95 percent CI, –0.70 to –0.33) and 1.17 (–1.42 to –0.93) kg for participants who were somewhat active (7,500–9,999 steps per day) and active (≥10,000 steps per day) at baseline, as opposed to sedentary comparators.

When taken as a continuous variable, each additional 1,000 daily steps correlated with a 0.11-kg drop in weight (95 percent CI, –0.14 to –0.09; p_trend<0.001).

The researchers also noted an inverse correlation between exercise regularity and weight change. Participants with the lowest degree of exercise variability (CV ≤40 percent) saw a 0.33-kg (95 percent CI, –0.53 to –0.13) greater decrease in weight than those with PA CV >63 percent.

The trend held true as well for moderate levels of variability. Weight loss was 0.19-kg (95 percent CI, –0.38 to –0.01) and 0.23-kg (95 percent CI, –0.41 to –0.04) greater in participants with PA CV from 51 percent to 63 percent, and from 40 percent to 51 percent, respectively. Every 10-percent increase in CV correlated with a 0.07-kg increase in weight (p_trend<0.001).

“From a public health perspective, our results suggest that weight-related health benefits can be observed below the controversial 10,000 steps per day threshold and emphasize the idea that ‘some PA is good, more PA is better’ with regard to weight loss,” the researchers said.

“Further investigations with complementary data on diet, sedentary behaviors, and PA intensity or cadence (steps/min), which will allow the calculation of time spent in moderate-to-vigorous and light PA intensities, are warranted,” they added.