It shouldn't be the exercise - are you eating enough for your increased activity level? When you've been doing a plan for a while it's easy to get into a rut so you need to shake things up - different HEs, different foods, recipes and menus. Any post your foods diaries on here so we can take a look and perhaps give some advice. But please don't resort to pills - over the counter ones don't work and others can be downright lethal. Don't give up!