This will be more concept-based and it’ll be up to you to apply it in your own way
Looking at the basics, training involves two things
External load is how much work/training the person is performing—for example, quantifying sets, reps, load lifted, exercise selection, etc. What is the person actually doing.
Internal load is what is being experienced internally resulting from the external loads. Things like fatigue, muscle damage, muscle soreness, hormonal changes, etc. What is happening inside the person in response to external loading.
Everyone is different. A certain dose of external load affects people’s internal load differently –
1.Too little external load = too little internal load = No and/or little improvement in strength as the body has not been disrupted enough from baseline to cause adaptations (i.e getting stronger and bigger)
2.Too much external load = too much internal load = A plateau in strength (doing more work for nothing) or a decline in strength from inadequate recovery. The body has been disrupted too much. Much energy is likely being allocated to repair with less energy being allocated to adapting.
3.Optimal external load = internal load is ideal = Rate of gains are optimal. The person can adequately recover from training and positively adapt which results in a gradual increase in performance
Based on the above information, training can be viewed as – What dose or amount of training does a person require to disrupt their body’s homeostasis to cause it to adapt and improve?
Also consider that external loads not only include training, but outside stressors such as stress, work, family commitments, etc. These can add extra internal load so less energy may be allocated to adapting and more to recovering
Finding how much training is ‘optimal’ shouldn’t be viewed as an exact amount but a range. There is likely a range of external loading someone can use to see optimal gains. Likewise, what is optimal is a moving target. More importantly is probably finding what someone’s lower and upper loading limits are. Once that has been established, you can play around with training between the 2 extremes