Britney Spears perfectly extending her leg while upside-down came with a massive Xmas injection last night. The 39-year-old pop princess updated her Instagram stories with a little evening workout action, and it was a doubled-down affair. Britney also posted two intensive dance videos showing the results of her years of yoga, a practice the "Toxic" singer vowed to do more of as part of her 2020 New Year's Resolution. Britney's 27.1 million followers actually got their favorite pop star totally upside-down. Check it out below.