timing how long it takes for your kettle to boil 1 cup (250ml) of water. looking at the power of your kettle (Watts, often found on the base of the kettle) joules = wattage x time (in seconds)
Rock climbing can help build and tone your legs and glutes. Indoor rock climbing is a sport that when properly executed, recruits every major muscle group in the body. Rock climbing is a full body workout that tones and strengthens the arms, shoulders and core muscles. You can also effectively strengthen and tone your legs and buttocks with regular indoor rock climbing sessions.
Isometric exercises can maintain your leg's muscle tone. It might seem like an oxymoron that you can exercise your muscles without actually having to perform a movement or lift weight. This is exactly what isometric exercises are. They work using only muscle tension in specific positions.