Despite the ubiquity of online fitness offerings from Pilates videos on YouTube to indoor-cycling smartphone apps, fitness experts say aging boomers reluctant to go with the streaming flow want their home exercise in a DVD format. Fitness DVDs generated $297.2 million in sales last year and are likely to remain popular with older audiences, according to market researchers, even as the industry's giants turn their focus to Web-based technology. "Every time I do a (DVD) shoot, I think this will be the last one, but we keep meeting our revenue goals," said Miami-based fitness instructor Jessica Smith, whose company JessicaSmithTV produces streaming and DVD fitness videos.