From BBC:
Getting out of a chair may seem too trivial a task to pay much attention to, but your ability to do so actually reveals a great deal about your health. To assess this, doctors use the sit-to-stand test (STS), which measures how many times you can rise to a standing position from seated within 30 seconds. It’s commonly performed in GP surgeries, or community settings when screening for health issues amongst older people, but it can also easily be performed at home.
“It’s a really helpful test, because it tells us so much about how well people are functioning,” says Jugdeep Dhesi, a consultant geriatrician at Guy’s and St Thomas’ NHS Foundation Trust in London and professor of geriatric medicine at Kings College London, in the UK. “It tells us about their strength, their balance and their flexibility. We know that there’s some studies that suggest that it can help to inform whether people are at risk of things like falls, cardiovascular issues or even at a higher risk of dying.”