The 47-year-old actor plays Superman's father, Jor-El, in the upcoming movie and has been opting for gym sessions, long bike rides, runs and walks so he is in the best shape possible for the part.
Writing on his twitter page, he said in a series of posts: "Yesterday 1 hr walk 1 hr gym, today pitiful bike ride but it is a very special day and i've got other things I need to do. go hard tomorrow.
"31.37 km bike ride. Bike 28.6 km, gym 1 hr. 2 walks, total time 1 hr 45 mins. (sic)"
The Oscar-winning star - whose weight has fluctuated over the years - recently shed 16lbs on a tough new exercise and diet regime, which involved following a gluten free eating plan and a punishing fitness schedule.
He tweeted: "220 lbs this morning, started at 236.4 lbs. 45 min walk, 12 mins eliptical, weighted objects 40 mins, walk 25 mins. 2400 cal a day maximum, all meals & all beverages. Where possible gluten free.
"Day 12 of a 105 day training period, there is a long way to go, one layer of tissue paper per day of effort and diet ... it takes a long time (sic)."