The thing about the bio passport, is if you get a rider young and get him on a blood boosting program before he has entered bio passport testing, then you can set a higher baseline for that testing - your young talent 'naturally' has a high haematocrit, and you can boost them even higher when they go on 'altitude' camp.
With Froome I always wondered if the whole Bilharzia story was cover for him getting on a blood boosting program - a good excuse for him to suddenly have a lot more red blood cells.
I was reflecting the other day that I feel with Froome and Sky we actually probably know all the secrets now.
We know that British Cycling were able to get early access to ketone drinks way back in 2012 - no doubt this means Sky were also using them.
We know that they were using triamcinolone to help with cutting, which explains why they were all so crazy thin but still powerful. Salbutamol was probably also part of this.
We also know they liked a bit of tramadol, which was no doubt used in a cocktail with a mixture of uppers (caffeine etc... maybe the salbutamol) to help riders push on for the big mountain stages.
I think professionally applied these together (with maybe a few cheeky little blood bags kept within the passport parameters) are enough to explain their dominance.
I don't know what riders are doing now, but the leap in performance post covid is crazy - huffing Carbon Monoxide is probably part of it, but it does feel like there is something else which has quite rapid effect (like literally, boosts performance several percent on that day) but which is either expensive or otherwise difficult to deploy repeatedly, and seems to be used in a targeted way - perhaps the lugworm blood we've heard rumoured?