He often pushed his body to extreme lengths to see the effects, including living with tapeworms in his gut for six weeks for a programme.
Hockey participation is climbing, a testament to the fun that can be had. But a lot of youth sports' problems can be seen in hockey, too.
Namita Singh meets the prime minister’s family members and former friends in the town where Narendra Modi was born and raised, and discovers how Vadnagar is being changed to rewrite its place in India’s history