I am a 22 year old male with a good deal of exercise experience. Lately however I have been struggling in deciding which of two exercise methods is most efficient for my goal of gaining weight/muscle while also staying lean.

Method 1: Exercise 4-5 times a week

-Each day exercise two muscle groups (i.e. triceps/chest, biceps/back, legs/shoulders)
-For each muscle group I do 3-6 exercises and 3 sets on each.
-I do low-weight high-reps with one muscle group and high-weight low-reps with the other. (For example on a triceps/chest day I will be doing high weight on triceps and low weight on chest)
-Three or so days later when I return to exercise the same muscle groups I will do ( low-weight on triceps and high weight on chest)
-I typically will try to swim or run each day
-This method takes a very long time and I am usually at the gym for close to 2 hours

Method 2: Exercise 4-5 times a week going twice a day.

-Like the first method I exercise two muscle groups each day, however I split them up into two separate workouts.
-For example in the morning I may exercise triceps at high weight and conclude with a swim. And in the evening I would exercise chest at low weight concluding with a run.
- I add a few extra exercises to each muscle group as going twice a day cuts down the amount of time I am at the gym for one sitting. ( Usually each workout is ~ 45 min-1 hour)


Which method is most efficient? Or should I be trying to do something else completely?

I appreciate any responses