Thankfully, I am not a dad, so I do not have to worry about receiving inappropriate gifts from my children for father's day, but the whole series of press releases from desperate plastic surgeons looking to drum up business seem to imply that all that the dad wants is a visit to the plastic surgeon for some age-reversal procedures. Stephen Greenberg claims that he “has seen requests for procedures around Father’s Day go up close to 50 percent among men; the highest level than any other time of year.”
Look, as I am getting older, I am aware of the visible signs of aging, and how that changes how people treat me, but the way I learned a long time ago that you do not want to give a gift a membership to the gym to your spouse (or for that matter anyone, unless this individual insists on receiving that gift), you do not want to gift anyone that reminds a man of his aging. As it is most likely his falling level of Testosterone is already playing havoc on his self esteem.
Yes, there maybe a time to remind a dude about doing something about his aging, and an offer to fund it, but for a day on which he may want to feel good: birthday, Christmas, promotion, etc., just give him something that will bring him joy without having to put much thought into it. In my opinion, some gifts that are bound to delight any man are a massage, tickets to a game/concert, vacation, meal, or something that he might use/need but has not bought/replaced (e.g. sunglasses).