Voted fittest female celeb by FitSugar readers two years in a row, we know Jessica Biel embraces a challenging workout. Jess recently shared the details of her new boot camp with Life and Style, and it sounds tough. After an hour-long session at Live-In Fitness Enterprise (L.I.F.E.) in Marina Del Rey, CA, the actress said that the workout "was tough, and I’ll definitely be back for more. But I’m tired!"