Martinez watched on as his charges brushed aside Manchester United 2-0 at Goodison Park on Sunday to leave themselves a point behind Arsenal in the race for a spot in next season's UEFA Champions League.
The clash with the defending champions was Everton's third game in nine days, whereas United had enjoyed an extended break since their Champions League exit to Bayern Munich.
"We had to be very clever in using our energy right," said Martinez.
"They had 11 days since their last game but we've been able to use the squad and I think that's been very important.
"The whole squad has been involved and that has been a difference probably.
"It's an important balance between having players who are fresh and players who have been contributing.
"I think we have the right balance with the squad now going into the final games of the season."
Everton are now relying on Arsenal to drop points between now and the end of the season, but the Spaniard says attempting to predict other teams' results is a futile exercise.
"When you're trying to guess, you're wasting your time," he said.
"The only thing you can focus on is the points tally you can achieve.
"Whatever happens elsewhere is just part of being involved in the best league in world football. If you're trying to guess scorelines you're going to get 99 per cent wrong."
