The 26-year-old, who scored a career best of 284 in England's total of 710 for 7 declared, justified the pace of England's innings.
The opening batsman faced 545 balls and batted for 803 minutes, prompting some pundits to criticise England for not upping the tempo.
"The old ball was quite hard to get away and they were setting quite defensive fields," said Cook.
"The pitch was a little slow and it was hard to hit through the line. We score generally quite quickly as a side but when you bowl a side out in two sessions you can bat as long as you want."
Sky Sports commentator Shane Warne criticised England for not scoring more quickly and for not declaring earlier via his Twitter account.
"Test cricket is entertainment - Eng on top but now very boring - on behalf of everyone watching - DECLARE Strauss !!!" Warne commented.
India continue their second innings on Saturday still 451 runs behind England's first innings total.