PARIS: French President Nicolas Sarkozy will reduce his workload for a few days after suffering a dizzy spell brought on by jogging in hot weather and a heavy schedule, his office said yesterday.

The leader of nuclear-armed France spent the night in hospital after falling ill while running, due to a combination of physical effort and tiredness, but not any cardiac problems, Sarkozy's office said.

"The diagnosis is a faintness from a sustained physical effort in great heat without a loss of consciousness, in a context of fatigue stemming from a heavy workload," his office said in a statement.