New Delhi, April 14 -- Harshita Modi proudly tells anyone who listens that her 9-year-old son, Staval, plays badminton for their club and is "always picked to represent his school in the flat race." In early March, she showed up at a Run Fit training camp in Kolkata to enrol herself and her son for an exercise routine based on athletic conditioning because her friends told her that several kids and women in their mid-thirties, like her, attend the sessions.

In Bengaluru, Siddhartha Arun, 14, loves playing cricket and is very serious about it. A year earlier, the teenager realised he needed to get stronger and walked into his South Bengaluru apartment gym. "I need to become stronger to get better at cricket. My mother lifts weights and I ...