In the devoutly traditionalist world of sport, a very modern trend is creeping into the mainstream.
Veganism - or more specifically for those following a vegan diet this month, Veganuary - is a word increasingly used in the same breath as discussion of sport (much to the disquiet of the steak pie-eating, match-going fan), helped on its way by a fair few extremely prominent advocates.
Plant-munching athletes occupy rarefied places across the sporting stratosphere: Lionel Messi, Novak Djokovic and Lewis Hamilton - all vegans - each have a good claim to be the greatest ever to grace their respective disciplines, while Virat Kohli, Venus Williams and several players from NFL Superbowl hopefuls the Tennessee Titans all claim to have reaped the benefits of changing their diet. And beyond the physical improvements these stars say they have enjoyed, there is the ecological argument of plant-based diets having a small carbon footprint - important to bear in mind when Greta Thunberg, as Roger Federer recently discovered, is monitoring our every word.
Football clubs are doing their bit to embrace the vegan revolution. Tottenham, Aston Villa and Crystal Palace are among the Premier League clubs to have added to their vegan offering at their stadiums for January (though it should probably be mentioned here that one of the two vegan options at Selhurst Park is chips, which you'd have to assume is not a new addition to the menu).
Beyond that, England Rugby have established a partnership with a vegan jerky company, while Netflix's much-discussed documentary Gamechangers argued the benefits of a plant-based diet for elite athletes. Yet for all the sense of empowerment an individual can glean from choosing not to eat animal products, avoiding them entirely in sport is nigh-on impossible.
Djokovic may trumpet his dietary choices, but his sport is hardly vegan-friendly: at Wimbledon 2019, where he won his fifth title, 54,000 brand new, wool-coated balls were used in its two weeks.
Instagram activist Hamilton - and his peers - drive in gloves with suede leather palms and boots with leather soles. And even if Messi's boots are synthetic, many of his colleagues' will be made of leather, while every football kit and boot manufacturer will use leather in many of its other products.
Cricket players wear wool jumpers on cold days in the field. The balls they play with have a leather exterior. Each basketball used in the NBA requires around four square feet of leather to make its coat. Baseball gloves are still made almost entirely from leather.
Clearly, playing cricket with your mates is not quite akin to foxhunting, but equally it seems hard to make a case for elite sport being able to coexist alongside veganism.
The scale of humanity's non-food based use of animal products is truly vast. According to a report by Grand View Research, the global leather goods market was worth $414bn in 2017, roughly $114bn - or 38 per cent - more than the beef industry. Leather is not, as many people will assume, a mere byproduct of the beef industry. Butchers do not kill a cow and then pass its hide to the local tannery. Leather-makers do not skin cows in the week and sell steaks at the weekend. These are two separate entities which exist and thrive independently. Sport plays a part in the continued success of the leather industry.
Clothing companies are under pressure to find animal-friendly alternatives to wool, suede and leather, so it follows that sport - if it is serious about reducing its environmental impact - should be encouraged to produce vegan equipment.
But a 2006 NBA experiment with a synthetic basketball failed in just three months with the ball so hard to grip that it was compared to "driving on an icy road", while it is difficult to see how cricket, so obsessed with maintaining the sanctity of the traditional five-day Test match, would ever consider changing to a non-leather ball when the ball plays such a crucial role in the game. Slazenger, meanwhile, says its wool tennis balls have "increased durability and responsiveness" compared to cheaper nylon alternatives.
Djokovic, Kohli and Crystal Palace are all doing their bit, but it might be a while before veganism and sport can truly go hand in hand.