Joe Root admitted the England Test captaincy had started to negatively impact his personal life after starring in his first international without being skipper against New Zealand.

Root stepped down as red-ball skipper following series defeat to West Indies, leaving England with just one win in their last 17 Tests.

Ben Stokes was subsequently appointed to lead his country in the longest format, with New Zealand great Brendon McCullum charged with transforming England's fortunes in the five-day game.

The new leadership pair's country of birth posed England's first task of the new era, and it was the familiar face of Root who delivered at the crucial time in the first Test.

Root became only the second England batter to score 10,000 runs in the longest format with an unbeaten 115, guiding Stokes' side to chase 277 and take a 1-0 series lead in the three-match series.

Yorkshireman Root is also the 14th player to reach that milestone and achieved the feat at exactly the same age – 31 years and 157 days – as his former team-mate and captain Alastair Cook.

Speaking to Sky Sports after the game, much of Root's focus was on the impact of not having to stress about the captaincy in his first Test without skippering duties.

"It was tough to step down as captain but I'd thrown everything at it, every bit of myself into it and it had started to have an unhealthy effect on the rest of my life," he said.

"I couldn't leave it in the car or at the cricket ground. It wasn't fair on myself or my family and I want to enjoy my cricket. It's a role that needs so much energy and you can see that within Ben."

The century was also Root's first in the fourth innings of a Test match, and he was delighted to deliver for both England and Stokes.

"I had thrown everything at it [captaincy] and I was determined to help turn this team around. But I realised over that time at home that it would have to be in a different way," he told reporters.

"I'm very excited to do that now, to do everything I can to help Ben turn this team around and make it the force it should and can be.

"I'll do anything I can to help England win Test matches and be a side people enjoy watching and can be proud of.

"It got to the stage where it was time for someone else to lead. I threw absolutely everything at the role. I'm proud of the way that I tried to do that."

Meanwhile, former Australia Test captain Mark Taylor believes Root can surpass India legend Sachin Tendulkar's record 15,921 runs in red-ball internationals.

"Root has minimum five years left in him, so I think Tendulkar's record is very achievable," Taylor told Sky Sports.

"He is batting as well as I have ever seen him bat over the last 18 months to two years.

"He is in the prime of his career, so there is 15,000 runs-plus for him if he stays healthy."