Sport England says its This Girl Can campaign is "changing behaviour" a year on from its launch.
Independent research says 2.8 million women aged 14 to 40 who recognise the campaign say they have done some or more activity as a result.
And 1.6 million of those women say they have started exercising.
The snapshot survey asked a sample of 1,000 women in November 2015 about the physical activity they did and their awareness of the campaign.
The initiative aims to inspire women of all ages to participate in physical activity and exercise.
"I'm very encouraged by these new figures," said Sport England chief executive Jennie Price.
"They show This Girl Can is not just being talked about, but is also changing behaviour."
However, she added that there is still work to do.
"With a gender gap of 1.73 million fewer women playing sport compared to men, we need to keep getting the message out there that women come in all shapes and sizes and levels of ability," said Price.
"They should all feel able to exercise and play sport."
Did you know?
- This Girl Can films have been viewed 37 million times on the campaign's YouTube and Facebook channels alone.
- 540,000 women and girls have joined the This Girl Can social media community.
- There has been 660,000 tweets using #ThisGirlCan
- The campaign has been talked about on social media every single day since it launched on 12 January, 2015.
- The campaign has been talked about in more than 110 countries.