There is reasonable science backing the idea that working out 6-8 hours after you wake up is optimal. But how many people can carve out time at 12 in the afternoon or later to workout?
For a person with zero push ups on the floor and no pull ups, a CrossFit routine that calls for 15 pull ups, 30 push ups and 60 squats is counterproductive and pointless. An elaborate bodybuilding programme with upper-lower split across 4 days would very likely result in poor adherence.
Instead compound and body weight movements programmed in 25-30 min chunks 4-5 times a week will likely result in better adherence. Once the client gets a taste and the habit for resistance training, they can go down the path of powerlifting, Olympic lifting, bodybuilding, calisthenics or whatever they choose.
There is a lot of evidence indicating optimal protein intake for a 70 kg individual is between 85 and 110 grams. But try getting a person eating 20-25 grams of low quality protein to 85 grams overnight with a complete rehaul in food selection. Spoiler alert: you are much more likely to fail than succeed. 50-60 grams is much more likely to result in adherence. And gradually bump it up to a more reasonable 80-85 grams.
Optimal is not always practical. Sometimes sub-optimal is more sustainable. The road to optimal is bridged with suboptimal habits. An imperfect program done consistently trumps a perfect program that one fails at.
