The 1D lads are getting buff

Niall Horan is suffering after putting in a few tough hours at the gym.

The One Direction singer, 19, has been training with strength coach Mark Jarvis but is finding his vigorous work-outs pretty painful.

‘@M1Jarvis I don’t like u! my stomach is on fire! Can’t move! Hate you ! Regards , Niall,’ Tweeted Niall earlier this week.

Mark replied: ‘@NiallOfficial I’m sorry Daisy. It’s what I do! 🙂 x.’

1D have all been getting fit with Mark to make sure they can handle their gruelling eight-month Take Me Home world tour.

Mark‘s excited fans by posting lots of sexy pictures of the lads – who are playing in Montreal, Canada tonight – looking sweaty.

He loves teasing Irish Niall about how hard he finds his exercise sessions.

‘@NiallOfficial Daisy, Daisy! How’s your stomach today Daisy?! Ready for some more tomorrow?! :),’ Tweeted Mark last night.

Niall replied: ‘@M1Jarvis did legs today daisy! Can’t walk ! Ready for tomorrow!lets do this sh*t!’

SEE PICTURES Niall Horan and One Direction in the Brits 2013: Stars party after the Brit Awards

SEE PICTURES Niall Horan and One Direction dance Gangnam Style at French music awards bash

SEE PICTURES Life before One Direction: Funny photos from Harry Styles, Niall Horan and Louis Tomlinson‘s school days

Anna Duff

VIDEO: One Direction‘s Harry Styles supports Cancer Research UK

VIDEO: One Direction coming soon


VIDEO: Teen Now meets One Direction part 1

 VIDEO: Teen Now meets One Direction part 2

VIDEO: One Direction at Capital FM Jingle Bell Ball part 2