you can still train heavy and tone up... maybe not as heavy because of the carb depletion but just change your diet and add cardio.. Myself and others I've talked to have tried 5x5 program while cutting and have been able to keep most of there strength and size.. but this also depends on your diet big time... you don't want to go from eating 3500 cals. to 2000 cals in a week, you will loose muscle faster than you've put it on..
here's a sticky that I've used that works great for dieting and cutting
http://www.bulknutrition.com/?articleID=30
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