I realize you say excluding training, but have you tried training biceps and triceps 2-3 times per week? They recover quickly when stimulated - not annihilated - properly and many have seen good growth from increased training frequency. I personally made my best gains on arms with training them twice a week.
Dr. Mike Isratel has good hypertropy advice for biceps and triceps, definitely worth a look to improve your training:
- Biceps - https://renaissanceperiodization.com/bicep-training-tips-hypertrophy/
- Triceps - https://renaissanceperiodization.com/triceps-hypertrophy-training-tips/
Dr. Mike Isratel has good hypertropy advice for biceps and triceps, definitely worth a look to improve your training:
- Biceps - https://renaissanceperiodization.com/bicep-training-tips-hypertrophy/
- Triceps - https://renaissanceperiodization.com/triceps-hypertrophy-training-tips/