Once again, 30-day fitness challenges are all the rage on social media. Whether it's a family workout challenge, a flat-abs-in-30-days challenge, or a popular 10-minutes-of-yoga-a-day-for-30-days ...

If you’re one of Meggan Grubb’s 1.3 million Instagram followers, you’ll know she’s no stranger to a bum workout. The fitness trainer and mum to 18-month-old daughter Winnie regularly shares snippets ...

The post has 6.7 million views, and social media users across platforms accepted the challenge. Many performed the test solo or in groups, at the office, or as a family or couple. #biologicalage feed ...