Historical clue formulations

• Workout focus, informally — 2023-12-10
• Heart-pumping activity — 2023-10-22
• Vigorous exercise — 2021-10-30
• Exercise on an elliptical machine, informally — 2017-06-27
• What spin classes provide, informally — 2015-03-10
• Healthful exercise, informally — 2006-08-06
• Part of many workouts, informally — 2005-12-31