Can exercise during pregnancy reduce the risk of gestational diabetes?

How much and what kind of exercise works best?

The most effective exercise for preventing GDM appears to be yoga. A 2025 network meta-analysis of multiple studies found that yoga was associated with an 81% lower risk of developing GDM compared to no exercise [1]. Aerobic exercise (like brisk walking, swimming, or stationary cycling) was also highly effective, reducing risk by 60% [1]. The same analysis showed that combining diet guidance with exercise reduced risk by 47% [1].

Intensity matters. A large 2025 study of over 9,000 pregnant women found that moderate-intensity exercise (7.5-14.9 MET-hours per week, roughly equivalent to 150 minutes of brisk walking) lowered GDM risk by 19%, and high-intensity exercise (15+ MET-hours per week) lowered it by 37%, compared to no exercise [5]. Low-intensity exercise showed no significant benefit [5]. Another 2025 study found that any participation in moderate-to-vigorous physical activity was linked to a 42% lower odds of developing GDM [2].

Starting early is key. The 2025 network meta-analysis found that exercise begun in early pregnancy was significantly more protective than starting later, reducing GDM risk by 49% [1]. A 2021 meta-analysis of 11 trials concluded that facility-based exercise programs started before the 20th week of pregnancy were particularly effective, cutting GDM risk by 47% [7].

Does exercise help if you're already at high risk for GDM?

Yes, the evidence strongly supports exercise for women at higher risk, such as those who are overweight or have a family history of diabetes. A 2022 meta-analysis of 9 randomized controlled trials involving over 1,500 high-risk women found that exercise during pregnancy reduced their risk of developing GDM by 30% [4]. The benefit was even greater—a 46% risk reduction—in studies where the exercise program lasted more than 20 weeks [4].

This protective effect holds across different body types. The 2025 network meta-analysis found that exercise reduced GDM risk by 37% in healthy-weight women, by 47% in overweight or obese women, and by 47% in women with other risk factors [1]. So regardless of your starting point, adding regular physical activity is a powerful tool.

What are the limitations and caveats?

While the evidence is strong, it's not universal. One notable 2025 randomized controlled trial (the 'BEFORE THE BEGINNING' study) tested a combined program of exercise and time-restricted eating started before pregnancy and found no significant effect on blood sugar levels in late pregnancy [3]. However, this study had low adherence to the exercise component during pregnancy, which may explain the lack of benefit [3]. This highlights a key real-world challenge: sticking with an exercise routine throughout pregnancy is difficult, and the benefits depend on actually doing it.

Another 2025 study using a physical activity questionnaire in a Turkish population found no link between reported activity levels and GDM diagnosis [6]. This may be because questionnaires are less accurate than objective measures (like activity trackers) or because the activity levels reported were generally low. The takeaway is that the quality and intensity of exercise matter more than simply being 'active' in a general sense.

Finally, it's important to remember that exercise is a preventive measure, not a guaranteed shield. Even with regular exercise, some women will still develop GDM due to other factors like genetics or age. But the evidence consistently shows that exercise significantly tilts the odds in your favor.

About These Sources

This answer is built on 7 peer-reviewed studies — published from 2021 to 2025, 5 from 2024 or later, 1 in Q1–Q2 journals — selected as the most relevant from 15 studies that passed quality screening, drawn from 88 papers retrieved from a database of over 500 million.

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