Russell jokes he should get ill more often after impressive qualifying in Abu Dhabi

"I've been really ill the last two weeks and I've been really, really quick," the Mercedes driver told Sky Sports television.

"So I don't know if I need to be ill more often or what it is. The last two weeks I've just felt super-comfortable in the car, had about on average three hours sleep per night so maybe that's the secret everybody's missing."

Fourth on the grid was still something of a disappointment after Russell had raised the team's hopes by going fastest in final practice.

Formula One reaches the end of a gruelling 22 race season on Sunday with the finale at Yas Marina coming on the back of an American swing and the inaugural Las Vegas Grand Prix last Saturday.

That involved a practice session ending at 4 a.m. local time, qualifying starting at midnight and a race that began at 10 p.m. on the Saturday.

Abu Dhabi is 12 hours ahead of Las Vegas, a punishing adjustment for the travelling circus with five races on three continents in the space of five weeks including a triple-header of Texas-Mexico-Brazil.

Alpine's Esteban Ocon skipped his media commitments on Thursday because of sickness and said on Saturday he was still feeling the effects of a fever.

"We didn’t see the sun for four days," the Frenchman said of the Las Vegas trip.

"It’s obviously not optimal to be in bed for two days before an F1 race."

Next year's calendar will stretch to a record 24 races.