Lee Clark says has no problem convincing his Kilmarnock players to up their work-rate - because the evidence backing it up is down in black and white.

The Rugby Park boss has been delighted with his team after claiming four points from their last two games away to St Johnstone and Inverness.

He believes the key to victory in Perth and a decent draw in the Highlands was the energy his side put into their performances.

And if any of his players doubt his assessment, Clark can quickly point to the statistical data put together by his back-room staff which shows a direct correlation between they graft they put in and the points they take out.

Now he wants his team to sweat it out again when they host Robbie Neilson's industrious Hearts on Wednesday night.

He said: "One of the things I wanted to improve on when I came to the club was the physical aspect. If you have high fitness levels you give yourself a chance in any game.

"It's been quite simple this season - our best results have come when our physical data is higher than the opposition.

"When we do the debrief with the players it is quite easy to show them the stats which show that when we run harder and further than the other side we more than likely get a positive result.

"When we have come off those levels, that's when we have suffered.

"I'd love to be Luis Enrique and have a team of globetrotters who sweep everyone else off the park with their scintillating football.

"We are where we are and deal with what we have to deal with.

"So the big thing for us is the fitness levels and we certainly won't be getting done over when it comes to those stats this season."