I'm prety sure he'll very noticably train slower.
I noticed a slower training with my 26 year old last year.
Now he is 27 and I will keep him until he pops 1 more time to round it up, altough I know I shouldn't because it probably will take me twice as long as with a 20 year old or so...
As a side note: Last week my 35 year old popped 1 level in FT after more than half a season FT training. ;)
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