You might call it sweating for a cause. The latest trend in charitable fundraising has taken on an athletic tone, from amateur boxers entering the ring to support cancer research in Haymakers for Hope, to women playing football in the annual Blondes vs. Brunettes game sponsored by the Alzheimer’s Association. Also, a small army of charitable organizations and Boston businesses put together a “Style with Heart” makeover to ift the spirits of a woman with cancer. Plus, we learn how one nonprofit is introducing the sport of lacrosse to city kids.