At 24, thanks to her dream body, Jen Selter has become a star of the Instagram social network. 0 SHARES 0 0 0 If it's important to do regular physical activity, whether it's to lose weight , build muscle, or keep fit, it's not always easy to stay motivated all year long . To help you achieve your goals, you can follow sporty women on social networks . We have selected five that will encourage you to take good advice and photos. Kayla Itsines A true fitness guru, Kayla Itsines is followed by 15 million people on Facebook and 7.7 million on Instagram . The 26-year-old Australian is among the 30 most influential people on the Internet in 2016 according to the Times. She has developed a whole series of e-books around the sport (the "Bikini Body Guides") and an application, "Sweat", which offers sports challenges, balanced recipes and training. Jen Selter Addicted to fitness, this 24...