Rock climbing and (in the winter) vertical ice climbing are totally fat-free, as is winter mountaineering.   Nordic skiing is close, but no cigar.   Fats clog the bunny trails.   Marathons are sadly close to getting polluted.   Witness that deathfat moron Mess Hellishday always spewing about how it’s going to do an IM Tri.   The fats will probably come with Fat Marathons and Tri’s so the “discrimination" against them won’t continue.   Whitewater kayaking is also close to fat-free--or at least serious WW runs are, anyhow.   Fats can be found on Class I water.   Competitive rowing is also fat-free, but there’s little room there for casual enthusiasts.   Downhill and freestyle cycling are also thus far fat-free.   Downhill is harsh so it’ll probably stay that way, but freestyle is vulnerable to becoming polluted.