Due to a tailwind helping to enhance the speed of the athlete in events like certain sprint races (100 and 200 metres), 100/110 metres hurdles, the triple jump and the long jump, there is a limit to how much assisting wind the athlete may perform under if the performance is to establish a record. If a tail wind exceeds 2 metres per second (3.9 kn) the result cannot be registered as a record on any level. However, the results within that competition still are valid because all athletes in a race would get equal assistance, and in field events it is just the luck of the circumstance at the moment of the attempt. The wind assistance maximums are only in regard to the validation of a record.
The exceptions are the combined events like heptathlon and decathlon. Here, the total score may be accepted even though some of the results had a tail wind of more than 2.0 m/s. Here, in events where wind velocity is measured, the average velocity (based on the algebraic sum of the wind velocities, as measured for each individual event, divided by the number of such events) shall not exceed +2.0 m/s (Rule 260.18). Higher average velocity was previously allowed as long as no individual event would exceed +4.0 m/s but the IAAF removed this rule in 2010.
There have also been cases where the prevailing wind has aided point to point long distance races like the 2011 Boston Marathon, however the nature of point to point courses invalidate allowable records by design.
Notable cases of strong wind assistance
Obadele Thompson ran the 100 metres in 9.69 seconds in April 1996 in El Paso. The result would have been a new world record, had it not been for the tail wind of >5.0 m/s. This was then bettered by Tyson Gay in June 2008, Gay ran a time of 9.68 seconds with the help of a +4.1 m/s tailwind.
Leroy Burrell ran it in 19.61 seconds in May 1990 in College Station, Texas, well under the world record at the time (19.72 - Pietro mennea - Mexico 1979) but with a tail wind of 4.0 m/s. Also, Michael Johnson ran in 19.70 seconds on 22 June 1996 during a semi-final race at the US Olympic Trials in Atlanta with a tail wind of 2.7 m/s. The next day, in the final race, he improved the long-standing world record to 19.66 seconds, which he improved further at the Olympic Games with a 19.32 in the same city in August.
100/110 metres hurdles
Renaldo Nehemiah ran a would-be 110 metres hurdles world record of 12.91 seconds in June 1979 in Champaign, Illinois with a tail wind of 3.5 m/s. Roger Kingdom later became the first person to break the 12.90-second-barrier, running in 12.87 seconds in September 1989 at the World Cup in Barcelona with a tail wind of 2.6 m/s. As of 2013, the world record is 12.80 seconds.
In June 1979, just days after equalling her own 100 metres hurdles world record of 12.48 seconds, Grazyna Rabsztyn ran the distance in 12.39 seconds in Bremen with a 2.8 m/s tail wind. The next year Rabsztyn became the first woman to legally run under 12.40 when she improved the world record to 12.36 seconds. Since then, other athletes have registered faster wind-assisted times, but none of them better than the world record (12.20 seconds by Kendra Harrison) as of July 2016.
Willie Banks became the first athlete to break the 18-metre-barrier in the triple jump, but with a tailwind of 5.2 m/s his 18.20 m jump in July 1988 in Indianapolis was not recognized as a world record. Mike Conley jumped 18.17 at the 1992 Summer Olympics, and the tail wind of 2.1 m/s was only marginally non-legal. Jonathan Edwards, who later became the first athlete to legally break the 18-metre-barrier with his current world record jump, jumped 18.43 metres in June 1995 in Villeneuve d'Ascq in a tailwind of 2.4 m/s.
In May 2007, Keila Costa became the first South American woman to break the 15-metre-barrier. Her 15.10 m jump in Uberlândia, Brazil had a tail wind of 2.7 m/s. Her legal personal best jump was 14.43 at the time, and the South American record was 14.53 metres. The next month Costa improved the South American record to 14.57 metres.
In the long jump, Iván Pedroso jumped 8.96 metres in Sestriere, Italy in 1995 to break the world record by one centimetre — however, the result was never accepted due to wind assistance problems. The wind gauge did show a legal tail wind of 1.2 m/s, but this was declared void as someone had been standing in front of the gauge, thereby interfering with the wind measurement and rendering the result unusable.
When Mike Powell set the world record at the 1991 World Championships in Athletics, moments before, Carl Lewis broke the existing world record by Bob Beamon with an 8.91, only to have it invalidated for record purposes by the +2.9 wind. Still in the competition, Powell then needed to jump over the world record to win the competition. He succeeded, and the wind had died down to only +0.3, enough to record a legal wind for the record as well. In a later competition, Powell jumped 8.99, but without setting a record due to a +4.4 wind.
Also, two Oceanian records were not recognized. Gary Honey jumped 8.39 metres in July 1984 in Sacramento, California, and Peter Burge jumped 8.48 in September 2000 in Gold Coast, Queensland. Both results had too strong tailwind. Only weeks after Burge's jump, the Oceanian record was improved with a legal 8.49 metres jump by Jai Taurima.
Dan O'Brien's decathlon result of 8844 points from June 1991 in New York City was better than the world record at the time, but not recognized due to wind assistance. The next year O'Brien set a legal world record of 8891 points, which has since been improved further.
In the heptathlon, wind-assisted series have been rare. Tatyana Chernova greatly outperformed the current world junior record of 6542 points with a wind-assisted score of 6768 points in June 2007 in Arles, France. Other wind-assisted series from Arles were recorded in 1987 and 2006.
- "Rule 260.14(c) of IAAF Competition Rules 2016-2017" (PDF). Retrieved July 29, 2016.
- Commonwealth All-Time Lists (Men) - GBR Athletics
- "Men's non-legal 100m". Retrieved 28 August 2015.
- All-time men's best 200m - wind-assisted - The Track and Field all-time Performances Homepage
- "Michael Johnson". Retrieved 28 August 2015.
- World Record Progression - 200 m men - The Athletics Site
- All-time men's best 110m hurdles - wind-assisted marks - The Track and Field all-time Performances Homepage
- World Record Progression - 100 m. hurdles women - The Athletics Site
- All-time women's best 100m hurdles - wind-assisted - The Track and Field all-time Performances Homepage
- All-time men's best triple jump - wind-assisted marks - The Track and Field all-time Performances Homepage
- All-time women's best triple jump - wind-assisted jumps - The Track and Field all-time Performances Homepage
- Biscayart, Eduardo (10 June 2007). "14.57 Area Triple Jump Record for Costa as South American Champs finish". IAAF.org. Retrieved 2007-09-05.
- "Athlete profile for Iván Pedroso - iaaf.org". iaaf.org. Retrieved 28 August 2015.
- IWAS World Games 2009 - Athletics Results
- All-time women's best long jump - wind-assisted jumps - The Track and Field all-time Performances Homepage
- All-time men's best decathlon - wind-assisted series - The Track and Field all-time Performances Homepage
- World Record Progression - decathlon men - The Athletics Site
- World Junior Records and Best Performances - GBR Athletics
- All-time women's best heptathlon - wind-assisted serie - The Track and Field all-time Performances Homepage