Among major upcoming sporting events, Red Bull's X Fighters motocross stunt world tour starts in Mexico City, the NBA Playoffs commence across the USA, and the World Chess Championship gets underway in Bulgaria.

Endurance: 25th Marathon des Sables
April 2-12
Sahara Desert, Morocco

The Sand Marathon certainly has earned its reputation of being the toughest footrace on earth. Contestants must be almost entirely self-sufficient over the six-day, 254km (156mi) ultra marathon. Over 1000 participants started this year's event, while families and curious onlookers can observe their progress via videos and interviews on the Marathon website.

Red Bull X Fighters World Tour
April 16
Mexico City, Mexico

The first stop-off in the six-stage, six-month tour takes in Mexico City once again as top freestyle motocross maniacs pull tricks and stunts inside the Plaza de Toros. After that, the riders visit Giza, Egypt in May, Moscow in Russia in June, Madrid in Spain in July, London in the UK in August, before a month's rest and the final in Rome, Italy, where the World Tour Champion will be crowned. Stadium passes are $295 MXN ($24 / €17).

Basketball: NBA Playoffs
April 17 onwards

The NBA postseason starts on April 17 and between now and then, teams from the Eastern and Western conferences are jostling for the 16 playoff places. Home court advantages go to the teams with better overall season records and as such may not be decided until the last regular games of 2009/10 on April 14th. Once the playoffs start, each matchup is a seven-game series, so the date of the Championship Finals and indeed the grand final itself aren't possible to specify in advance. However, the two finalists typically settle the title by mid-to-late June. US broadcasting rights are split between ABC, ESPN and TNT, though of course the NBA TV network will also be covering the games.

Motor sports: Red Bull Air Race
April 17-18
Perth, Australia

The second Red Bull Air Race of the season stops off in Perth, Australia, flying over the Swan River with qualifying on April 17 and the racing itself on April 18. Last season's champion, British aviator Paul Bonhomme, is already leading the pack after placing first at this year's opener in Abu Dhabi. Race footage will be shown on One and Fox Sports in Australia, Channel 5 and Sky Sports in the UK, RTL and Motorvision on Germany, and J-Sports in Japan. Those countries that do not have television deals tied up can watch a live video on the Red Bull Air Race website. One-day grandstand tickets are AUD$45 (€30) on the Saturday, AUD$95 (€65) on the Sunday. Children are approximately half price, and there are also more luxurious hospitality arrangements available.

Formula One: Chinese Grand Prix
April 18
Shanghai, China

This year's hopefuls in the driver and manufacturer championships will head to Shanghai for the fourth race in the 2010 Formula One calendar. Though Felipe Massa leads the world championship after three races, only four points separate the top five drivers - Alonso, Vettel, and Button each have a win under their belts (unlike Massa), and Rosberg's decent finishes see him through to 5th. Out of the previous six Chinese GP winners, only Vettel and Hamilton are still racing for the same team, as Schumacher is now at Mercedes GP, Alonso at Ferrari, Barrichello at Williams-Cosworth, and Hakkinen now in the WRC. A two-day F1 Paddock Club pass sets spectators back €2,685 ($3,585), only marginally pricier than a one-day ticket. or

Intellectual: World Chess Championship 2010
April 21 - May 12
Sofia, Bulgaria

Two of the world's best chess players compete in a 12-game match schedule for the WCC's €2 million prize. World number four Veselin Topalov, FIDE World Champion 2005-2006, goes head-to-head with number two and current reigning world champion Vishy Anand. There was considerable indecision regarding the location of Topalov's qualification match, in which he beat world number three Vladimir Kraminik who was the World Champion of the then rival PCA organisation. The WCC 2010 games will be broadcast live from the competition's official website.

Sailing: Eastern Mediterranean Yacht Rally
April 23 - June 28
Istanbul, Turkey

The aim of the amateur EMYR is to cover 1585 nautical miles (1825mi / 2940km) over the course of 67 days, taking in Northern Cyprus, Syria, the Lebanon, Egypt, on the way from Turkey's capital Istanbul before finishing in Herzliya in Israel. Twenty-four ports in total make up the six-country course, which also includes 12 world heritage sites.

Sailing: Fireball World Championships
April 24 - May 7

Barbados welcomes some of the best and fastest two-person sailing crews for these World Championships, an annual competitive meet for racers using the Fireball class of sail boat. Small, 16ft length boats with a three-panelled hull, these boats are at their stablest when in motion and their highly adjustable rigging means that despite their size, they offer a high degree of customization to crews. Registration costs £375 (€430) for participants, and passes to the social events are also available to non-sailors at £95 (€110) for adults, £55 (€65) for juniors and free for children.

Tennis: Fed Cup Semifinals
April 24-25
Rome, Italy and Brimingham, Alabama, USA

The Italian and WTA number 11 Flavia Pennetta will be joined by Sara Errani, Francesca Schiavone, and Roberta Vinci in hosting the Czech Republic's WTA Doubles number 8 Kveta Peschke and her compatriots Iveta Benešová, Petra Kvitová, and Lucie Šafárová at the Stadio Nicola Pietrangeli. Meanwhile, WTA joint number one Liezel Huber of the USA will be playing with Christina McHale, Melanie Oudin, and Bethanie Mattek-Sands in Birmingham, Alabama against the Russian ladies' team of Svetlana Kuznetsova, Vera Zvonareva, Nadia Petrova and Anna Chakvetadze.

Endurance: Ironman South Africa
April 25
Port Elizabeth, South Africa

The only event in the Ironman 2010 series to take place on the African continent, Ironman South Africa represents the only regional opportunity for African triathlon enthusiasts to secure a place at October's World Championships in Hawaii. 1,855 competitors have been registered for the race, which starts with a 2.4mi / 3.8km swim in Nelson Mandela Bay, a 112mi / 180km cycle west past the Airport to Sea View and back again along the coastal Marine Drive, before finishing off with a 26.2mi / 42.2km three-lap fast and flat run in and near the Nelson Mandela University grounds.

MotoGP: Japanese Grand Prix
April 25
Motegi, Japan

The Twin Ring Motegi track, so called because it incorporates both a speedway circuit and a road course within its bounds, is host to only the second race of the 2010 MotoGP season on April 25. Though its sharp turns and short straights are not universally popular with riders, they can approach 350kmh down its long straight. For spectators planning to watch in person, there are six grandstands, and standard three-day passes cost between €97/$130 and €168/$226 each, depending on grandstand location and comfort required.

Intellectual: World Sudoku Championship
April 29 - May 2
Philadelphia, Pennsylvania, USA

Now in its fifth year, competitors at the World Sudoku Championship are chosen to represent their country by their nationally approved World Puzzle Federation organization, listed on the World Puzzle website. Up to six individuals and one three-person team can be sent. Registration closes on April 5: fees of $420 (€310) for competitors and $700 (€520) for guests include accommodation in the official Championship hotel.

Cricket: ICC World Twenty20
April 30 - May 16
Various locations, West Indies

Zimbabwe, Afghanistan, and Ireland join the world's nine top-seeded teams on West Indian islands including Barbados, and St Lucia, and St.Kitts & Nevis to contest the Twenty20 title over a series of short matches. After a week of warm-up games, the Super 8s commence the tournament's knock-out stage from May 6 onwards, building up to the climactic semi-finals on May 13 and then the final on May 17. Sky Sports and the BBC cover the competition in the UK and Ireland, Eurosport in mainland Europe, ESPN in Asia and India, while Fox and Sky also have Australia. Canadian and Afghani viewers can catch the matches on ATN - distinct yet similarly titled broadcasting companies.

Motorsport: Gumball 3000
May 1-7
London, UK - New York, USA

The Gumball motor rally travels 3000 miles (4828 km) from London to New York, via the European cities of Amsterdam, Copenhagen, and Stockholm, before flying over the Atlantic and continuing the seven-day tour through Quebec City and Toronto. The Gumball 3000 is well known for attracting wealthy and famous participants: Idris Elba (Stringer Bell from The Wire), Dizzee Rascal, Jade Jagger, Tony Hawk, Xzibit and Cypress Hill's DJ Muggs are all confirmed entrants for 2010. Upwards of 100 cars will be travelling point to point, many of them super-expensive supercars done up in custom livery, though it's not uncommon to see more diminutive vehicles. Idris Elba, for one, has taken to the spirit of the rally by selecting a Mini Cooper as his ride.

MotoGP: Spanish Grand Prix
May 2
Jerez de la Frontera, Spain

After the Japanese Grand Prix, MotoGP sheds its usual fortnightly schedule and immediately sets up camp in southern Spain for the third meet of the season. Weekend passes bought via the MotoGP website start at €63/$75 for general admission and go up to €107/$128 in the best grandstand. Tickets are also available from the Circuito de Jerez's own site. or