well i originaly followed the split reccomended originaly
but i then changed it becuse i couldnt bare training shoulders before chest day, and training my shoulder before a back day
and i couldnt bare training arms before shoulders, nor training arms together
so i changed my split about 4 weeks in to
monday : legs, biceps
tuesday: chest, calves
wednesday: rest
thursday: back, rear delts abs
friday: shoulders (front and middle only), triceps, traps
saturday: rest
sunday: rest or repeat
reasons for this split
legs trained monday because NO one trains on mondays, also the 3 day break on the weekend allows for good CNS recovery, so IMO its best to hit the BIGGEST muscle group when ur CNS is at its best
i trained biceps with legs becuase it gives them alot of rest before they are trained during your back workout, so it minimises chances of overtraining ur biceps, or fatigue in your biceps to hinder your back workout
chest on a tueday becuase less people train chest ona tuesday so ull have more availability for bench presses etc at the gym, calves are hit after chest becuase they take minimal work to train, so best to put them on a day when youve already trained hard
rest day follows these 2 to give ur CNS a break becuase uve hit 2 really big muscle groups (chest and legs)
back is then trained becuase its the best distance away from ur bicep day following a 7 day split, its also after a rest day so ur CNS has better strength to train another major muscle group (ur back) and its trained on it own becuase back requires alot of CNS strength, i placed abs on this day becuase if you do any form of hanging leg raises etc it places stress on your lats, so its best to stimulate ur lats by training abs on ur back day to maximise recovery during their 7 day break.
rear delts are placed on back day becuase they are directly hit during pull ups, rows etc, so training them on back day allows them 7 full days of recovery, alwise training them on shoulder day would result in less recovery time since theyll be hit on back day, also if they are still fatigued form shoulder training they can hinder ur back workout making ur back workout less effective, which is i big problem
shoulders, triceps, traps follow becuase their smaller muscle groups, also since triceps are hit indirectly on chest day, its best to seperate them as far as possible from chest, they are also stimulated during shoulder press movements so its a good idea to put ur triceps on your shoulder day since theyll receieve stimulation doing a shoulder press movement
traps are trained with shoulders since the middle delt exercises usually also hit the trapius muscle, so its a good idea to stimulate the 2 together, rather then seperatly and risk hindering either ones workouts becuase one is fatigued from a seperate workout
2 rest days are then given to give good CNS recovery and time for smaller muscle groups to recover before they are indirectly hit the following week before being trained directly again
this is an effective split IMO foir above reasons, other people may have other opinions and preferences which is fine, i just find mine works for the above reasons, just thought id justify it so u can understand why i like the split