What we’ve learnt from the world most “researched” race!
By Kathleen Mc Quaide (Sports Scientist, Health Promotions Manager, SSISA)
Arguably one of the world’s most beautiful ultra’s, particularly as it returns this year to the original route which includes the majestic Chapman’s Peak, the Two Oceans can also boast another title, that of being the world’s most scientifically researched race!
Says Prof Tim Noakes, who holds the position of Discovery Health Chair of the Exercise Science and Sports Medicine (ESSM) Research Unit, “Over the past 30 years, Two Oceans has probably contributed more to scientific research on marathon and ultramarathon running than any other single race in the world, having generated more than a score of scientific journal publications from studies over this period of time. Whilst the earlier studies in the 70’s were very rudimentary, techniques have now become very specialized allowing elaborate research to take place”.
So it seems particularly fitting that some 3 decades later, we see the cementing of a relationship between the Two Oceans Race and ESSM, who has been the only research team conducting the studies. The formal relationship will allow ESSM to engage in a long-term programme of highly integrated research on Two Oceans Runners. Two Oceans Marathon participants will be invited to add their names to an ever-growing research database, and these volunteers will form a cohort of runners who will be able to take part in many planned investigations for as long as they continue to run. There will be studies on muscle tissue, bone health and genetics, to mention but a few. Not only will the individual runners find out a tremendous amount about their physiology, their potential and how to improve their running, but high-level, integrated research will also be made possible.
Race Director Chet Sainsbury, Two Oceans Race Director and life member of Mr Price Celtic Harriers, the organizing club of the Two Oceans, is thrilled with the formalising of the relationship with ESSM. He adds “We have had a fantastic relationship with Tim and his team over the last 30 years. They have proved themselves to be internationally renowned, world-class scientists and therefore I am delighted to be able to assist their research which will be of tremendous benefit to runners as well!”
So what have we learnt from 3 decades of research on Oceans? Here are just some of the issues that have been tackled.
The earliest research study, conducted in ’74 taught us that the concentration of blood biochemicals such as creatine kinase and C-reactive protein, which are markers of muscle damage, increase substantially with the marathon distance (hence the sore muscles post-race!) Creatine kinase rises even more precipitously with the Two Oceans Ultramarathon and the longer we are on the road, the higher the escalation! However, subsequent research has also shown that physical training reduces the leakage of these substances from damaged muscle during prolonged exercise, which means less pain!
When muscle breaks down, some of the by-products could possibly impair kidney function and for this reason, there was concern that kidney failure might be an unpleasant complication strongly associated with ultramarathon running.
A study in the ’86 Two Oceans, showed that not only was kidney function maintained during the period of the ultra, it was actually enhanced in the 48 hours post-race (probably in an attempt to get rid of all of the non-toxic proteins from muscle damage). Noakes believes that if kidney failure does occur, it is most likely linked to that particular individual’s genetic predisposition to excessive muscle breakdown during exercise.
What’s the relationship between menstrual patterns and bone strength in female ultramarathon runners?
In the ‘70’s, it was believed that any woman who ran over 80km’s per week would lose her periods (no longer menstruate), because of the excess stress of running. In the ’85 Two Oceans, this theory was put to the test and it was found that in fact multiple factors influenced the menstrual status of female; training was just one of them. Runners most likely to exhibit disrupted menstrual cycles were; younger, had started running at a young age, trained longer distances, had low body weight, had experienced disrupted menstrual cycles and tended to be the best performers. Noakes points out that the more “risk factors” a woman has, the greater the chance of menstrual dysfunction.
Disturbance of the menstrual cycle can have health consequences, which include long-term loss of bone mineral density, potentially leading to osteoporosis. To investigate this further, 40 women, who completed the ’91 Two Oceans, had bone mineral (bone density) testing. The study showed a definite link between any prior menstrual irregularity and a reduced bone density. In more recent times, researchers now refer to the female athletic triad of amenorrhoea, disordered eating and osteoporosis; if a female runner presents with one of the above, doctors will look out for presence of the other two conditions. Immediate, appropriate treatment or management can potentially prevent the worsening of these conditions.
In 2004, if anything, we have to be cautioned not to “overdrink”, whereas prior to 1969, runners believed that it was actually dangerous to drink or eat during prolonged exercise! Noakes gives the example of Jackie Meckler (5 times Comrades winner), who considered not drinking anything during a marathon as a “sign of fitness and perhaps macho-manliness!” By the early ‘80’s, fluid consumption was being encouraged and Comrades icon, Bruce Fordyce was avidly preaching the importance of carbohydrate consumption during ultramarathons. In the ’81 Two Oceans , Noakes’ team measured various blood biochemicals related to carbohydrate and fat metabolism in runners of varying ability. These tests were repeated with Comrades and Peninsula Marathon runners. They found low glucose levels (which indicate inadequate carbohydrate supplies possibly impairing performance) in 3% of Two Oceans runners, compared to 9% of Comrades runners. Extensive subsequent research has shown conclusively the benefits of carbohydrate consumption in races longer than 30km. (include Table of CHO requirements for Two Oceans Ultra?)
With regard to fluid consumption, until last year, international guidelines were actually recommending runners drink more fluid than is actually necessary. However, as a direct consequence of 18 years of intense research by Noakes and his team, including that conducted on Two Oceans runners, the “fluid consumption war” finally ended with the USA Track and Field’s acceptance of Noakes’ guidelines on “Hydration during long-distance running”. These represent a major shift in policy away from former American College of Sports Medicine (ACSM) thinking and are now employed at all marathons and ultras throughout the USA!
How to deal with the collapsed athlete?
Another set of guidelines, now employed globally, which emanated from Two Oceans research conducted by the ESSM team at the ’83 and ’84 Oceans, were those for the treatment of post-exercise collapse. Previously, it had become commonplace for race doctors to hook up the collapsed athlete to an intravenous drip; the presumption being that the athlete was dehydrated. However, studies that examined levels of dehydration and fluid intake in the collapsed runners, showed that they weren’t excessively dehydrated.
The collapsed runners were more likely to have; undertrained for the race; consumed too few carbohydrates during the run; skipped breakfast; been sick prior to the race.
Subsequent studies also showed that 85% of the runners collapsed after the finish line – which is a very telling point! As Noakes points out, had they been dehydrated, they would in all likelihood have collapsed during the race, when their circulatory systems were under severe stress! The very simple explanation for the post-race collapse was therefore as follows: when you run long distances, blood flow to the muscles in the legs is increased and if you suddenly stop running, the blood pools in your legs, and the resultant low blood pressure you experience (postural hypotension), can result in your collapse. The correct treatment, ESSM researchers found, was simply to raise the runners’ legs above the level of their heart (Strover manoeuvre), allowing the pooled blood to return to the heart more easily and be redistributed around the body. Needless to say, this saved a lot of time for staff in the medical tent, since within 20 minutes of this “treatment”, most runners got up and walked off feeling much better!
Are you at greater risk of colds (upper respiratory tract infections) after running an ultra-marathon?
According to research conducted by Dr Kiessig at the ’96 Two Oceans, the answer is no! The symptoms of respiratory infection long-distance runners often experience, are more likely due to local inflammation of the respiratory tract as a result of “hard breathing” for an extended period.
In the ’99 Two Oceans, Prof Lambert and Lara Keytel found that the training volume of top male and female runners in the year preceding the race was similar. Generally the older male runners trained less in the 3.5 months prior to the race, than the younger ones, whereas with female runners, the weekly training distance was not affected by age.
Research on Two Oceans shows that sadly this is not the case. Whilst a regular running programme certainly improves your cardiovascular health and decreases your overall risk of mortality, it doesn’t confer immunity against heart disease on the runner.
The ’94 study by Dr Nicol on Two Oceans athletes confirmed that there was no association between changes in certain electrolytes (sodium, pottasium, calcium or magnesium) or dehydration, and cramping (taking an electrolyte supplement or drinking more water won’t help to prevent cramping!) The researchers also found that 65% of the cramping was experienced in the last 14km of the race and was associated with muscle fatigue. They also found that the best method for relieving cramps on route was to stop and passively stretch the cramping muscle; slow down and to stretch any cramp-prone muscles throughout the race (every 5 – 8km). Effective training for the race, with sufficient long runs would also decrease runners’ risk of severe muscle fatigue.
Lisa Micklesfield, who has just completed her PhD on “Physical Activity and Bone Health through the various life stages“, hopes to investigate the prevalence of menstrual dysfunction and disordered eating patterns in the women participating in the 56km and 21.1km Two Oceans 2004 races; she also wants to determine if there are any ethnic differences associated with the above. A later investigation, will look at the relationship between male runners’ eating patterns and their bone mineral density.
Dr Malcolm Collins, specializes in genetic research and a mere sample of runners’ saliva, from which DNA will be isolated, will be used for intense genetic studies. Collins’s main investigations will be trying to identify and locate “performance-linked” genes (units of genetic material), as well as attempting to establish the molecular mechanism of premature ageing in the muscles of certain runners. This research question has arisen since many talented athletes have reported to ESSM with a sudden drop off in performance after years of remarkable achievement. ESSM have already done extensive studies looking at their muscles, training techniques etc, but these genetic studies will add a new dimension to this investigation and perhaps help to answer existing questions.