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Running Research News And Events
January 13, 2012
High-Rep, Short-Recovery Strength Training Gets Runners Into Hydrogen-Management Industry
When you are running fast, hydrogen icons (protons) tend to pile up in your leg-muscle cells. Although it is no longer clear that such accumulations automatically induce fatigue (1), it is very probable that they can have a negative impact on overall muscle-cell function (2). When you are finishing the last 400 metes of a 1500-meter, 5-K, or 10-K race at a furious pace, climbing a hill during challenging competition, or making a powerful within-race surge, it is nearly certain that you are better off if your leg-muscle concentrations of protons are moderate, rather than high. High-Rep, Short-Recovery Strength Training
But how do you maintain proper proton prudence during hard running? We know that high- intensity interval training can help in this matter (3), but the effects of strength training on hydrogen-ion frugality are less clear. One inquiry found that athletes who engage in regular strength training have better proton regulation, compared with non-strength-trained individuals (4), but the control subjects in this research were untrained individuals, leading skeptics to suggest that training per se - and not necessarily strength training - causes proton modulation to prosper.
Nonetheless, there is good reason to believe that resistance training might give muscle cells a hand with their hydrogen problems. One key is that vigorous, high-rep strength training has been shown to produce a large drop in intramuscular pH and a significant rise in blood-lactate concentration - similar to the changes which occur during high-intensity running (5). These "signals" associated with resistance training may act as they do after top-quality running, producing appropriate muscular adaptations and upgrades in hydrogen-handling capacity.
To find out if strength training really works in this way, highly regarded researcher David Bishop and his team from the School of Human Movement and Exercise Science at the university of Western Australia recently worked with 16 female athletes who were involved in such sports as hockey, netball, and soccer (6). Eight of the subjects carried out a high-repetition strength-training program (with three to five sets of 15 to 20 reps per exercise) over a five week period, while the other eight served as controls. High-Rep, Short-Recovery Strength Training
Both groups continued with their usual athletic pursuits over the five-week time frame, and the strength-training regime utilized a combination of free weights and exercise machines. The first six exercises of the strength-training workouts emphasized the legs and included squats, lunges, and step-ups (all completed with free weights), along with leg presses, leg extensions, and leg curls (performed with machines). To balance out the leg activities, upper-body exertions were incorporated into the sessions, including bench presses and shoulder presses (with free weights), along with seated rows and lat-pull-downs (carried out on machines), and even good-old-fashion sit-ups.
The resistance utilized per set was gradually reduced so that the athletes could perform at least 15 reps in each 40-second time period.
For each exercise, the appropriate number of sets (three to five) was completed before the athlete moved on to the next exertion. Each set was performed for 40 seconds ( and thus for 15 to 20 reps), followed by a 20-second rest. Since this rest period was fairly short, the resistance for sets following the first one was reduced (so that the athletes could still hit 15 to 20 repetitions within their sets). This meant that the first set was conducted at 70 percent of the RM load (e.g., 70 percent of the resistance which could be handled for three - and only three reps), the second set at 60 percent of 3RM, and sets three through five at 50 percent of 3RM.
The athletes actually completed two to three sets of each exercise during the first two weeks of the project and then three to five sets during the last three weeks of the research. When the subjects could complete 20 reps of a particular exercise for all sets during two straight workouts, the total load was upgraded by the smallest amount available for the relevant piece of equipment. As a practical matter, this meant that the advance in weight lifted during an exercise such as leg pressing was about 10 percent per week. A five-minute warm-up on an exercise bike tuned up the women prior to each strength-training session. High Rep, Short Recovery Strength Training
And how did the female athletes respond to all this lifting? After the leg exertions within a typical strengthening session, blood-lactate levels soared to an average of 9.1 mmol L-1, similar to the concentration which is commonly observed after a hard running workout conducted at an above-lactate-threshold intensity. Heart rate was also rather lofty, scoring at 85 percent of max.
Although body mass did not change, leg-press 3RM strength improved by 23 percent after five weeks (but remained unchanged for controls). The strength training also improved the ability of the athletes to carry out a high-intensity sprint-interval training session which involved 5 X 6 seconds of maximal sprinting, with 24-second recoveries. Total work performed during this workout advanced by 110 to 12 percent after five weeks for the strength-trained athletes, but not at all for the control individuals. Peak power attained during each of the sprints also advanced for strength-trained females (but again, not for controls).
To learn more about how High-Rep, Short-Recovery Strength Training Gets Runners Into Hydrogen-Management Industry (the full article can be read by purchasing Vol. 22 Issue 8 of Running Research News) and many more running related topics, simply click-on the Back Issues link, and select the volume and issues number, from the drop-down menu. A subscription to Running Research News is another way to receive valuable information about running. Running Research News Subscription
January 13, 2012
Vitamins C AND E Seems To Provide Protection For Endurance Athletes' Airways
Relatively low levels of ozone (<120micrograms/m3) can affect lung function in endurance athletes, making it more difficult to bring large volumes of air into thelungs (Respiratory Effects of Low-Level Photochemical Air Pollution in Amateur Cyclists," American Journal od Resp. Crit. Care Medicine, vol. 150, pp.962-996, 1994). As a result, exercise scientist have searched for years to find ways to minimize ozone-related respiratory problems in athletes. Vitamins C And E
Ozone, also known as O3, is actually an unstable form of oxygen. If you have been even mildly interested in atmospheric science and air pollution over the past few years, you are well aware that there is "good ozone" and also "bad ozone" in the earth's atmosphere. The "good ozone" occurs naturally in the upper atmosphere, approximately 10 kilometers above the earth. There, it forms a protective layer which helps to shield the earth from the harmful rays of the sun.
At ground level, however, the very same gas becomes "bad ozone." Ground-level ozone can harm human lung tissue, crops, and manufactured materials. The ground-level O3 is formed when nitrogen oxides and reactive organic gases (hydrocarbons) react chemically in the presence of sunlight. Nitrogen oxides, of course, are produced by fuel-burning engines; reactive organic gases are released by motor vehicles, solvents, a variety of different consumer products, and petroleum-processing plants.
Ground-level ozone tend to induce bronchoconstriction (narrowing of the airways), which decreases air flow into the lungs and potenially limits oxygen delivery to the blood. Even though endurance athletes have well-trained respiratory systems, they are quite prome toozone-induced problems. That's because athletes can maintain very high ventilation rates for prolonged periods of time - and thus drag more ozone into their lungs, compared to "couch potatoes". In addition, the "mouth breathing" (instead of routine nasal breathing) associated with heavy exercise takes away one of the body's key lines of defense against ozone - the trapping of ozone molecules in the nasal membranes, which prevents the irritating gas from reaching the lower air passages. If you live in or near an urban area, it's likely that ozone is having at least some impact on your respiratory function when you train and race. Vitamins C And E
What can you do to protect yourself from ozone's effects? Theorizing that antioxidants might help control ozone-related damage to the airways, researchers in Mexico City recently gave "antioxidant cocktails" to street workers exposed to fairly high levels of ozone. These cocktails contained vitamin C, vitamin E, and beta-carotene, and they did indeed have a protective effect on lung function in the workers (:Antioxidant Supplementation and Respiratory Function among Workers Exposed to High Levels of Ozone," American Journal of Respiratory Crit. Care Medicine, vol. 158, pp. 226-232, 1998).
Dutch Cyclist, Ozone, and Vitamins C and E
These workers were not exercising hevily, however. Would a similar cocktail have a beneficial effect in endurance athletes - even at lower ambient levels of ozone? To find out, researchers at Wageningen Agricultural University and the Netherlands Institute of Health Sciences in the Netherlands recently divided 38 Dutch cyclists (35 males and three females) into two groups: Members of one group received a daily dose of 500mg of vitamin C and 100 mg of vitamin E, while cyclists in the second group ingested only a placebo. The study was carried out in a "double-blind" manner (neither researchers nor athletes initially knew who was actually getting the potentially protective vitamins).
During the study, the cyclists worked out and competed in their usual manner. Average workout duration was 104 minutes, and mean workout heart rate was 141 beats per minute, but race pulse rates ascended to an average of 173 bpm. The athletes' lung functions were checked after workouts and races ( a total of 380 different tests were performed). Ozone concentrations were moderate; average ozone level was 77 micrograms/m3, and he range ws 14-186 micrograms/m3; this corresponds roughly with an average of .055 ppm and a range going up around .12 ppm ("Double- Blind Intervention Trial on Modulation of Ozone Effects on Pulmonary Function by Antioxidant Supplements," American Journal of Epidemiology, vol. 149, pp. 306-314, 1999).
Blood levels of vitamin E shot up about 48 percent in the supplement group, and plasma vitamin C rose by 4 percent; concentrations of two vitamins were essentially unchanged in placebo cyclists. When the researchers looked at average ozone levels during the eight hours before testing, they unearthed an interesting fact: As ozone levels increased, the amount of air the athletes could force out of their lungs in one second and the quantity of air they could exchange with the enviroment decreased in the placebo group - but were unchanged in the vitamin-ingesting cyclists. In other words, the vitamins seemed to protect cyclists from losses in respiratory function associated with ozone exposure. Vitamins C And E
For example, when ozone levels increased by about 100 micrograms/m3, the placebo riders could force 95 ml less air out of their lungs during a forced exhalation, while the drop-off for the supplementers was only 1 ml. C and E seemed to be reducing the extent of bronchoconstriction.
It's unclear what effects these differences would have on performance times, but it's clear that the C and E supplementation helped keep the athletes' airways more open and should have made intense exercise feel more comfortable. In a separate study, subjects took daily vitamin C (250mg), vitamin E (100mg), and a vegetable-based cocktail for two weeks, after which they were exposed to ozone levels of 800 micrograms/m3 (.4ppm) during two hours of exercise. During this period of exercise and ozone exposure, decrements in lung functioning were modest in the supplementers, compared to individuals who took in only a placebo ("The Role of Dietary Antioxidants in Ozone-Induced Lung Injury in Normal Human Subjects, " American Journal of Respir. Crit. Care Medicine, vol. 157 (supplement): A195, 1998).
But, do you really need to worry about ozone's effects on your lungs? After all, isn't it true that air quality is getting better?
Well, ground-level ozone levels are dropping. For example, last year ozone levels in the Los Angeles area exceeded California state standards on "only" 114 days. While that might seem like a lot, it was down from an average of 242 over the limit days 20 years ago.
Health advisories - when ozone soars above .15ppm and everyone is advised to avoid vigorous outdoor exercise - were in effect on "just" 43 days in Los Angeles 1998, down from 184 outrageous days in 1977, and there were "only" 12 "stage-1 Episodes", when ozone levels rocket above .20 ppm and people start getting really sick.
In other words, the air is getting cleaner, but in major urban areas like Los Angeles it still contains enough ozone to produce problems. Even the Dutch countryside, which is not notorious for its severe air pollution, contained air with enough ozone to interfere with respiratory function in the Dutch cyclists described above. Unless you live in a pristine wilderness, taking vitamin C and E to protect your lungs seems to be a fairly reasonable thing to do. It won't neccessarily help you attain a new PR, but it should have at least some positive influence on airway function. Vitamins C And E
In addition to taking Vitamins C and E, what else might you do to protect your lungs from ozone? Here are some tips:
To learn more about Vitamin C and E, along with other informative topics. Like:
(the full articles can be read by purchasing Vol.15 Issue 2 of Running Research News) and many more running related topics, simply click-on the Back Issues link, and select the volume and issues number, from the drop-down menu. A subscription to Running Research News is another way to receive valuable information about running. SUBSCRIBE NOW!