India captain Virat Kohli on Tuesday admitted that lack of intensity and poor body language was one of the main reasons for the hosts suffering a huge 227-run defeat against England in the first Test here. With this win, England have taken a 1-0 lead in the four-match series."Our body language and intensity was not up to the mark, second innings we were much better. We were better in the second half of the first innings with the bat, not the first four batters," said Kohli at the post-match presentation ceremony."We have to understand the things that we have done decently in this game and the things that we haven't and as a side we are always looking to improve. England were far more professional and consistent throughout the Test match than we were," he said.After winning the toss, England posted a massive first-innings score of 578, riding on skipper Joe Root's 218. Dominic Sibley and Ben Stokes also made notable contributions of 87 and 82 respectively. In reply, India posted 337, and conceded a lead of 241. In their second innings, Indian bowlers performed much better as they bowled England out for 178, thanks to off-spinner Ravichandran Ashwin who took six wickets for 61. Chasing 420, India were bowled out for 192 in 58.1 overs in the second session of the fifth and final day."I don't think we put enough pressure on them with the ball in the first half. Collectively as a bowling unit, fast bowlers and Ashwin, were good in the first innings but we also needed to contain a few more runs and create pressure," said Kohli."Having said that, it was a slow wicket and not helping the bowlers which made it easy for the batsmen to rotate strike and get into the game. [It] just looked like not much happening in it on the first two days. But credit to England, they got stuck in and put up a big total on the board," he said.Kohli called upon the top-four batsman to contribute more in the upcoming matches. The 32-year-old player further pointed out that sub-par performance from young spinners Washington Sundar and Shahbaz Nadeem was also one of the reasons why India failed to contain the English batsman."That's a fair assessment [the fourth and fifth bowlers not being up to the mark]. You need your bowling unit to step up and create pressure on the opposition. We didn't achieve that in this game which is fine, lack of execution is acceptable but to understand our mindset was right is very important for us," he said."I think we did well in the second innings with the ball and put pressure on them. With the bat as well we left a few things to be desired and analysed as batsmen with the kind of decisions we took. We are always learning as a side and evolving as a side and Test cricket is tough," he said.Kohli insisted that India would come out with a better performance in the last three Tests and give their all to win the series.A place in the World Test Championship is also at stake. New Zealand hace already reached the final, to be played at Lord's, London, in June.The two teams will play the second Test at the same venue, beginning Saturday.