As mentioned, nausea and vomiting are common symptoms of anxiety and stress. While vomiting can be a symptom of anxiety, it's not as common as nausea. Behaving anxiously activates the stress response.
On December 8, 2016, Cinemax and Sky1 announced they had greenlit a brand new series of Strike Back with a brand new cast, no longer focusing on former stars Sullivan Stapleton and Philip Winchester. Daniel MacPherson, Alin Sumarwata, Roxanne McKee and Warren Brown have been cast to star in the new series.
Their vulnerability was even more pronounced in this season of Strike Back. The series is much better for it. It gives the characters more depth. Nitpicking aside. This was one of the best action series we've seen in a long time. I highly recommend it.