AM and PM are associated with 12-hour timekeeping, as opposed to the international 24-hour clock. The 12-hour system grew up mainly in Northern Europe, and spread globally from there via the British Empire.
The adjective STRENUOUS has 2 senses: 1. characterized by or performed with much energy or force. 2. taxing to the utmost; testing powers of endurance. Familiarity information: STRENUOUS used as an adjective is rare.
Tudor-Locke's research established these categories for healthy adults based on the steps per day they logged. 1  Sedentary Lifestyle Index: Under 5000 steps per day is an indicator of being inactive and sitting too much, which raises health risks.