1 Add time each week to work your way up to 30 to 45 minutes of continuous exercise. 2  As you get stronger, try interval training once a week to help boost endurance and burn more calories.  Work your way up to 5 to 6 days of cardio and try to vary what you do and how hard you work.
To achieve a sear on the outside and keep it rare inside, place the tuna on the skillet or grill and let it sear for two minutes on the first side. Flip the tuna and let it cook for another two minutes, then remove it from the heat. Watch the tuna as it cooks to make sure you don't overcook it.
Light the grill while tuna is marinating. Once coals are white (30 minutes) spread them and clean the grill, then wipe with oil so steaks don't stick. Grill for 4 minutes or less per side for 1 inch steaks, depending on how you like them.Steaks should be firm with pink in the middle. If you prefer steaks to be more rare, grilling time should be 2 1/2 minutes on each side.ight the grill while tuna is marinating. Once coals are white (30 minutes) spread them and clean the grill, then wipe with oil so steaks don't stick. Grill for 4 minutes or less per side for 1 inch steaks, depending on how you like them.