The effort of concentration and attention in prayer is both spiritual and physical.
Physical effort does not mean that one engages in dramatic gestures.
The rebbe of Rizhin did not take an unusually long time to pray, and he gave no appearance of doing anything unusual.
But after he finished, he had to change all of his clothes because they were soaked with sweat.
Although on the outside no effort or particular movement was noticeable, his body had made an extraordinary effort.
Indeed, refraining from an outward show can be more difficult than any such display.
–Rabbi Adin Steinsaltz