I am training back and biceps, chest and triceps, legs and shoulders as my routine. But I don't feel much stronger when I am doing biceps and triceps on different. I want to change the routine so that I can do them twice a week. What could be the routine?
How long have you been doing this? It takes time and continuity to get stronger, so just keep going. If you've been doing this for a while now and don't seem to get much progress I'd say switch it up a little. It depends on how often you go aswell. I for myself try to go to everyday and I plan my week so that I can do biceps and triceps twice a week.
I want to change the routine so that I can do them twice a week
For example I do Biceps on Monday and Thurdays (with enough rest days in between) and triceps on Tuesday and Friday. I hope this is what you meant and it helps. If not I'm open to answer more questions.
Edit: spelling (not a native speaker so excuse some mistakes)
Below is an example of a 6 day split which I have used in the past to hit every body part twice per week. It is a variation of the Push/Pull/Legs split
Monday: Shoulders + Legs
Tuesday: Chest + Triceps + Abs
Wednesday: Biceps + Back + Traps
Thursday: Shoulders + Legs
Friday: Chest + Triceps + Abs
Saturday: Biceps + Back + Traps
In this split, you train your biceps with your back and your triceps with your chest. The reason for this split is because your biceps are involved in most compound back exercises (Pullups, Rows) and your triceps are involved in most compound chest exercises (Bench Press, Pushups).
I don't think it is a good idea to have 2 dedicated days for just biceps and triceps. For example, If you train your biceps twice a week separately from your back muscles, you may overtrain them, because you will be working them twice with triceps and again on back day. Even if you are not focusing on your biceps, they are involved during many back exercises. If you train your back on Tuesday and train your biceps on Wednesday, you are essentially working your biceps two days in a row. Your muscles recover and grow when they are at rest, not when you are training them