Jessica Biel's Trainer Jason Walsh Gives Tips for Staying Fit Over the Holidays

Jason Walsh joined fellow celebrity climbers in Hollywood last night to celebrate their upcoming week-long hike up Mt. Kilimanjaro for charity in January. As Jessica Biel's longtime trainer, Jason signed on to help prepare the stars for the rigorous journey, but he ended up feeling passionate about the cause which is raising money to provide clean drinking water for children in Africa — learn more about it at the Summit on the Summit website. We asked Jason about the secret to Jessica Biel's amazing body and his tip for staying healthy through the holiday season.

Want to sample a Jason Walsh workout? He created a circuit workout exclusively for FitSugar readers. It's fun and fast and will help you tone up this holiday season.