Sunil Gavaskar was the first player ever to score 10000 runs in test cricket while opening for his team in batting but without wearing any helmet, that too against bowlers you have named.
He never had any fitness problems, like a tennis elbow, etc. He never missed a match for fitness related issues.
Of course in those days no. of matches were far less than what it is today. But at the same time we must admit that they never had these high profile coaches and the support staff appointed by BCCI.
