India, Dec. 29 -- There are many known indicators for a sustainable, healthy lifestyle, such as the body mass index (BMI).

However, according to Dr Saurabh Sethi, a California-based gastroenterologist trained in AIIMS, Harvard, and Stanford Universities, long-term well-being is better predicted by strong legs more than anything else.

Taking to Instagram on 28 December, Dr Sethi noted that for adults over the age of 40, the decline in leg strength increases the risk of falls, fractures, loss of independent mobility, and even death.

"Hip fractures carry a 20-30% mortality in older adults," he warned, explaining that the leg holds over half of the body's total muscle mass and is its biggest "metabolic engine."

Well-developed leg muscles ...