Fabio Cannavaro believes Real Madrid need to improve their fitness if they are to progress in the UEFA Champions League.
The Spanish giants got their Group E campaign off to a poor start after going down to Lyon 2-0 on Wednesday evening.
Cannavaro acknowledges Real were not at the races against the Ligue 1 outfit and now wants to work on their fitness.
"We played very badly and Lyon were much quicker than us particularly in the first half," explained Cannavaro.
"I think the problem is basically a question of fitness. I see this as the important factor more than lapses in concentration."
Real goalkeeper Iker Casillas echoed Cannavaro remarks and believes Lyon, who began their Ligue 1 season a month before the start of La Liga, were in better shape.
"They are a very strong team. They were very quick up front and on the counter, and grew in confidence with the number of chances they created," said Casillas.
"They were in better shape than us and this was clear to see on the pitch. We have to look to take the positives from the game but in all honesty there were very few."