what is the best 3/4 day split for muscle mass

[gramtheman48]

I am a runner but need to put on some weight, as I have been overtraining and now underweight.. can anyone recommend the best 3 /4 day splits?/

 

[mixedfeelings]

@gramtheman48 3 day split = full body
4 days a week = upper lower spilt

 

[faithglendale]

@gramtheman48 3 day split PPL 4 day split upper/lower x 2