Jane Fonda’s passion for exercise is only having more powerful as she receives older: The 85-year-aged actor and weather activist is constantly encouraging her 2.1 million Instagram followers to stay active. And at a new party hosted by H&M in New York Town, she shared that doing the job up a very good sweat is not the only cause she prioritizes fitness—it retains her mental wellbeing in examine too. “I didn’t know that [exercise] was critical to do ’til I was in my 30s,” she reported, per Men and women, joking that she documented having a “‘constant period’ all through school” to get out of collaborating in fitness center courses. “It wasn’t…