Tom Holland (left) and Jake Gyllenhaal (right) have both partaken in the handstand challenge on Instagram. Ryan Reynolds (centre), however, declined to get involved. Instagram 
Tom Holland (left) and Jake Gyllenhaal (right) have both partaken in the handstand challenge on Instagram. Ryan Reynolds (centre), however, declined to get involved. Instagram 

What is the Instagram handstand challenge? The agility feat that counts Tom Holland and Jake Gyllenhaal as fans