Peter Snell was a New Zealand runner who won three gold medals in the 800 and 1500 meter races in the 1960 and 1964 Olympics. He also set two Olympic records and seven world records. In 1962, at age 24, he won an 800-meter race in the world record time of 1:44.3. That time is arguably one of the most impressive world records at any distance because he was wearing stiff leather spikes on an incredibly slow grass cricket field, with a time that would have won most subsequent Olympics on super-fast tracks including those in 2000, 2004, and 2008.

Snell stopped competing in track and field at age 27, but continued to compete successfully in seven different events in ABC’s televised Superstars contest for celebrities, won several international triathlons and orienteering competitions, and was a competitive cyclist.

In his late 60s, he developed cardiomyopathy, which is damage to the heart muscle, and at age 72, he passed out and crashed his car into several parked vehicles. His doctors felt this was caused by low blood potassium from the many medications he was taking. He was diagnosed with an irregular heartbeat called atrial fibrillation and had a pacemaker and defibrillator inserted in his chest. On December 12, 2019, he was sleeping in front of a television set when his wife heard him let out an unusual noise. She said, “I tried to wake him up but he wouldn’t move. The paramedics came in about five minutes but they couldn’t wake him either.”

A Life in Running
Snell was born in New Zealand in 1938, and was very good at every sport he played in school. He won running races at every distance, excelled at rugby, field hockey and cricket, and won tournaments in tennis, badminton, and golf. At age 19, he met his future coach, Arthur Lydiard, who told him that he has so much natural speed that he could be the best middle distance runner in the world if he did “endurance training,” which included 22-mile runs every Sunday. Lydiard helped Snell dominate middle distances by making him do seasonal training in which he ran more than 100 miles a week most of the year and then, as his important races approached, he would run a few almost-all-out intervals four or more days a week. Snell was probably the world’s first natural sprinter to do this type of training, and it helped him win three Olympic gold medals and set two Olympic records and seven world records. However, running more than 100 miles a week and doing almost 100 percent effort intervals in the racing season comes at a price. He was training at his physical limits and retired from competitive running at age 27.

After Retirement from World Track Competition
After his track career, Snell worked for a few years in public relations for a tobacco company and then took a biology course at Loughborough University of Technology. At age 33, he moved to the United States and earned a bachelor’s degree in human performance from the University of California, Davis, followed by a PhD in exercise physiology at Washington State University. At age 45, he became a research fellow at the University of Texas Southwestern Medical Center at Dallas, and eventually he was appointed associate professor and director of its Human Performance Center. There he met and married Miki Hervey Snell, an American age-group record holder at 400 meters and 800 meters who competed at a high level in several different sports. Snell published many articles on how exercise affects the human body and heart, and on various diseases in athletes.

Can Extreme Exercise Damage the Heart?
In one of his articles, Snell wrote that an exercise as simple as walking helps to prevent heart attacks, strokes, and certain cancers, and may prolong life (Circulation, July 5, 1999). However, there is concern that athletes in extreme endurance competitions, such as marathons, ultramarathons, ironman distance triathlons, and very long distance bicycle races, can develop severe stretching of the chambers of their hearts that can cause evidence of temporary damage to their heart muscles that completely return to normal in less than a week (Mayo Clin Proc, Jun 2012;87(6):587–595; July 2012;87(7):704).

Mark Spitz, winner of seven gold medals in swimming in the 1976 Munich Olympics, was recently diagnosed with the same type of irregular heartbeat reported in Snell (NBC Sports, Sep 4, 2019). Some studies suggest that currently-competing endurance athletes are at increased risk for:
• heart muscle scarring (J Appl Physiol, 2011;110:1622–1626)
• plaques in heart arteries (Eur Heart J, 2008;29:1903–1910)
• atrial fibrillation (Scand J Med Sci Sports, 2017;27:910–917).
Other researchers have questioned whether repeated muscle damage can in rare cases cause permanent scarring called patchy myocardial fibrosis that can cause irregular heartbeats and death (Curr Treat Options Cardiovasc Med, Aug 28, 2018;20(10):84).
New Research on Intense Exercise
High Calcium Artery Score Doesn’t Always Mean High Risk for a Heart Attack 

Lessons from Peter Snell’s Heart Problems
Research data show that exercise protects your heart from damage and diseases and prolongs your life. However, there is a question whether extreme competitive endurance exercise can damage your heart. At present we have no good evidence that it does, but we have examples of some great endurance athletes who have suffered heart diseases. Time will tell whether the heart damage in these endurance athletes was caused by endurance exercises or was really caused by the same factors that cause heart damage in non-athletes, including:
• genetic susceptibility
• a pro-inflammatory diet with a lot of meat and sugar
• exposure to harmful chemicals and pollutants
• infections and other sources of inflammation
At present, the incidence of extreme endurance athletes having heart problems is so far below that of the general population that nobody can say for sure that extreme endurance exercise has been proven to damage the heart.

Sir Peter Snell
Dec 17, 1938 – Dec 12, 2019