From Longman Dictionary of Contemporary Englishaerobicsaer‧o‧bics /eəˈrəʊbɪks $ eˈroʊ-/ noun [uncountable] DSOa very active type of physical exercise done to music, usually in a classGRAMMAR: Singular or plural verb?Aerobics is followed by a singular verb: Aerobics is fun when you do it to music.
Examples from the Corpus
aerobics• On my right, there was a waist-high wall overlooking an aerobics class in full swing one floor below.• He started running an aerobics session in a church hall in Neasden, North London, and soon expanded.• My mum's started going to an aerobics class.• If it rains, the programme will be aerobics, papiermâché mask making, craft work and painting etc.• I do aerobics twice a week.• If it's raining, aerobics will be followed by table tennis and craft work.• This entitles you to our complete workout facilities, including weight room, aerobics classes, and sauna.• She was thankful she had taken aerobics classes and belonged to a walking club.• Have you ever tried aerobics?• Nigel also took up aerobics at his local sports centre.• Fitness programs feature water aerobics, self-defense techniques and strength training. 