Strong training app Ladder has partnered with singer and actress Hilary Duff for its first-ever celebrity deal. The company's "Hilary Duff Trains on Ladder" campaign aims to increase women's focus on fitness for strength purposes, not just appearance, as opposed to focusing on appearance. The campaign was featured on the app, which has 400,000 users worldwide and around 80% of them are female. According to Ladder data, the app has seen a significant shift in how females approach fitness, with 41.5% of women listing gaining strength as their primary purpose before joining Ladder compared to 9.7% before. The partnership coincides with Duff's plans to embark on a world tour.