Celebrity trainers often have short windows of time to train their clients.
They also don't always have access to gyms.
Romana Braganza's client list includes Halle Berry, Scarlett Johansson and Zac Efron.
To get an effective workout without a gym she uses circuit training which employs a 3:2:1 ratio of cardio, strength training, and core exercises.
This includes 1 minutes of standing ab crunches, three minutes of diagonal leg extensions and a minute of jumping jacks.