Quadrobics is a form of physical exercise that involves using all four limbs, as if imitating animal movements.^{[1][2][3][4][5]}

The word "quadrobics" is a portmanteau of the words "quattuor" (Latin for "four") and "aerobics". Quadrobics began as a sports hobby and over time turned into a trend that started to take over social networks.^[6] It is said to have been invented by Japanese sprinter Kenichi Ito, who in 2008 set the world record for running the 100-m track on all four limbs. Four years later, he beat his own record and was listed in the Guinness Book of Records.^[11] As of 2025, the record is 15.66 seconds, set by American Collin McClure in 2022.^[12][13]

Quadrobics is not yet officially recognised as a sport,^[16] but its enthusiasts organise competitions within their communities.^[17] As a sport, quadrobics is close to parkour.^[18] As a fitness activity, it, according to Vogue, "combines elements of aerobics and callisthenics" and, having been designed to "engage all four limbs simultaneously", provides an "effective full-body workout". As fitness expert Tomi Akande explained to the magazine, a quadrobic workout routine trains several major muscle groups, improving strength, agility, and coordination.^[19]

The basic quadrobics movements include:

• running or walking on all fours / trotting (e.g. crab walks, lizard walks);^[19][20][15]
• crawling (e.g. bear crawls);^[19][20]
• leaping;
• balancing;
• high jumps;
• mountain climbers [wikt];
• the renegade row [wikt].^[20]

In Russia, the quadrobers (or quadrobists) youth subculture combining cosplay (dressing up as animals) with quadrobics (like running around on all fours)^[23] drew public attention in the spring of 2024. On 16 April, the head of the League for Safe Internet, Ekaterina Mizulina, drew attention to Internet hate messages that called for beating up people named "quadrobers". A week later, the commissioner for children's rights of the Republic of Tatarstan, Irina Volynets, spoke alarmedly about children in animal costumes and the necessity to define the line between play and deviation.^[24] In September, a viral video featuring singer Mia Boyka who, in front of a concert audience, ridicules an 8-year-old female fan wearing cat ears and a tail caused a scandal^[27] and led to a discussion of the new quadrober phenomenon on the Russian 1st Channel talk show Let Them Talk, spanning several episodes.^[28][29]

The subculture is popular mainly among children and adolescents aged 8 to 14.^[30] Quadrobers wear animal costumes and also imitate animal movements and behavior: walk on all fours, growl, bark and meow, climb trees and interact with fellow quadrobers as if they all were animals.^[21][31][9] The species of animals most popular among quadrobers are cats, foxes, dogs, and wolves.^[15]

Quadrobers are often confused with furries, but there are differences. Quadrobers focus on imitating real animals, while furries role-play anthropomorphic animal characters (thus creating so-called fursonas, a portmanteau of "fur" and "persona").^[6][9]

The difference between quadrobers and therians is that therians truly get into the role of an animal (the one they feel spiritually connected to)^[32] and identify as such,^[33] while quadrobers see quadrobics as a physical activity and a sport. Neither quadrobers nor furries consider themselves animals.^[32]