The International Olympic Committee (IOC) on Wednesday confirmed five new sports to be included in the Tokyo 2020 Games.

Skateboarding and surfing, among others, will now have a place at the games. This adds 18 new medal events to the Tokyo Games – and more than 470 athletes. This comes as two new disciplines are being unveiled during the Rio Games.

IOC President Thomas Bach said in a press release: "We want to take sport to the youth."

"With the many options that young people have, we cannot expect any more that they will come automatically to us," he added.

CNBC highlights the new sports we'll see in Rio and Tokyo, alongside some of the also-rans.

Disclosure: CNBC parent NBCUniversal owns NBC Sports and NBC Olympics. NBC Olympics is the U.S. broadcast rights holder to all Summer and Winter Games through the year 2032.

International Skateboarding Federation President Gary Ream told CNBC via e-mail, "Skateboarding has grown from a fad in the 1960s to the center of mainstream youth culture by the early 2000s.

"It got there by maintaining its own culture and ecosystem though endemic media." As to why the sport was selected for Tokyo 2020, he adds, "Skateboarding leads the world in terms of socially connected and technologically savvy young participants."

Surf lifesaving was a demonstration sport at the Paris Games in 1900, and 120 years later, surfing will be an Olympic competition in its own right.

Alun James, a sports sponsorship expert and managing director of consultancy firm Four Communications told CNBC via telephone: "Both skateboarding and surfing clearly show the IOC's attempt to appeal to a millennial audience. The sports are lifestyle-oriented, as well as very dramatic and visual, which would have influenced the decision to include them."

Three types of climbing events are to be included: Lead, speed and bouldering. Climbing has enjoyed a growing international profile in recent years, and was a demonstration sport at the 2014 Youth Olympic Games in Nanjing, China.

Rob Adie, competitions and climbing walls officer at the British Mountaineering Council told CNBC via telephone that, "climbing is popular in Europe, but it's also huge in Asia, with China and Japan (is) also very into the sport."

"One of clear trends of the Olympic selection was sports that are attractive to the domestic market. Karate is obviously very Japanese in its orientation, but the sport may have to lobby hard to remain beyond 2020," James at Four Communications told CNBC.

Karate joins judo, its fellow Japanese martial art, which is already part of the Olympics.

Also part of the Japan-focused trend with the sport being huge in the country. James told CNBC that Japan is probably the sport's second-biggest market.

"Global participation has already doubled since the vote in 2009 (to include rugby sevens in the Rio Games), with women's participation increasing by five times." Bernard Lapasset, the chairman of World Rugby, a governing body for rugby union, said in an online press release.

According to World Rugby, 7.2 million people now play the game across the federation's 120 national member unions.

James at Four Communications told CNBC that golf is one of the "most international sports, though ironically it's not too popular in Brazil."

He added that the sport has been struggling for numbers, which may be linked to Nike's decision Thursday to stop selling golf equipment due to falling sales.

Nonetheless, in the build up to Rio 2016, the International Golf Federation has helped to launch Rio StreetGolf, a social project that involves using adapted equipment to make the sport possible in any urban environment.

Cricket is considered by many to be the most common spectator sport in the world, after soccer. This is largely due to its popularity in the densely populated Indian subcontinent, though the sport is a big hitter across Commonwealth countries.

As to its exclusion from the Olympics, James say: "The size of the Indian market distorts viewing figures." "Practical issues also need to be considered: The sport takes a long time to play and requires large grounds," he added.

Though squash is included in the Commonwealth Games, Pan-American Games and Asia Games, it has not been selected as an event in recent Olympics, despite campaigns for entry.

A sporting activity for the mind, the World Chess Federation has continuously lobbied for the IOC recognized sport to be included in various Olympic Games, even introducing drug testing for its competitors to comply with IOC rules. Chess was a demonstration sport at the Sydney 2000 Games.