Which of the following is not a valid stroke in a swimming competition?

The correct answer is Leg Stroke. 

Key Points

• Leg Stroke:
• This is not a recognized stroke style in competitive swimming.
• Though kicking is a fundamental part of most strokes, it is never performed alone in competitions.

 Additional Information

• Breaststroke:
  • In this type of stroke, the swimmer swims on his chest, and the torso does not rotate.
  • The legs kick out in a kind of "froggy" style while the hands pull through the water in a circle in front of the body.
  • The swimmer breathes at the end of each cycle.
• Front Stroke (or Freestyle/ Front Crawl):
  • This is commonly referred to as freestyle stroke, and it is the fastest swimming stroke.
  • It's characterized by the swimmer being on his belly and alternating the arms for strokes while the legs perform a flutter kick.
• Backstroke:
  • Also known as the back crawl, swimmers do this stroke on their backs.
  • It involves flutter kicking in the water while rotating the arms in a windmill motion.
  • It is the only regulated stroke to be swum on the back, and breathing is not restricted because the swimmer's face stays above water.