There’s a lot that goes into executing action sequences, and Frank Grillo would know this better than most people. Grillo has had plenty of action-heavy roles, with projects like The Grey, Zero Dark Thirty and The Purge films under his belt. However, many might know him best for starring alongside Chris Evans in Captain America: The Winter Soldier, and it would appear that working on that project proved to be intense.
Article source: https://www.cinemablend.com/news/2547696/why-training-for-the-winter-soldier-with-chris-evans-was-grueling-according-to-frank-grillo