Quick Hit Summary

Today, we have the privilege of picking the mind of Dr. Jaime Cooper who has a MS in Exercise Physiology and a PhD in Nutritional Science. Besides a strong academic background, Dr. Cooper is an avid endurance athlete. Topics that we cover include her background, research, and favorite research journals. In addition, she shares with us her pre-race carb loading techniques and post race recovery strategies.

Dr. Jamie Cooper

Figure 1 Dr. Jaime Cooper

Readers, I would like to introduce you to a new series I’d like to call Interview With The Expert. For each article, I will be talking with various experts in human performance field.

For this inaugural segment, I’m honored to have Dr. Jaime Cooper, PhD, spending her time with us. Dr. Cooper earned a BS and MS in Kinesiology- Exercise Physiology at Michigan State. While earning these degrees, Dr. Cooper spent time researching coagulation and fibrinolytic responses to exercise. Upon completing her master’s degree, Dr. Cooper’s quest for knowledge led to the University of Wisconsin-Madison where she earned her PhD in Nutritional Sciences. Currently, Dr. Cooper is an assistant professor in the Department of Nutritional Sciences at Texas Tech University in Lubbock, TX. Here she teaches general nutrition and sports nutrition at the undergraduate and graduate levels. In addition, Dr. Cooper is active in the research field where most of her time is spent studying human obesity. More specifically, she examines the relationship between nutrition, exercise, hormones and how their interactions affect human health. Dr. Cooper’s work has been published in respected journals such as the American Journal of Clinical Nutrition, Journal of the American Dietetics Association and Obesity.

Dr. Cooper is also an accomplished athlete in her own right. She has completed four marathons including the Boston Marathon. That’s just for starters. She has also completed several sprint distance triathlons, a ½ Ironman, and 2 full Ironman triathlons. For those not familiar with the Ironman triathlon competition, this 1 day event consists of a 2.4 mile swim, followed by a 112 mile bike ride. If this isn’t brutal enough, the event concludes with a 26.2 mile run.

Dr. Cooper, thanks for taking time out of your busy schedule to join us today.

While at Michigan State, you spent time studying coagulation and fibrinolytic responses to exercise. I was hoping you could go a little more in-depth on the research you completed there and any results that were found.

Acute exercise leads to an increase in clotting potential (formation of blood clots). To counteract this possible detrimental response, the body has a fibrinolytic system that works to break down blood clots. The fibrinolytic system also increases in response to exercise. Our research lab studied both the coagulation and fibrinolytic responses to different modes of exercise (running and snow-shoveling) and different intensities (maximal and sub-maximal). My thesis was on the time-course of fibrinolytic changes in response to maximal exercise¹.

Recently one of your articles was published in the prestigious American Journal of Clinical Nutrition [2]. In the study you examined the effects of saturated and monounsaturated fatty acids on energy expenditure and health risks. Could you briefly explain your study and the results your research team found?

Previous research has indicated that the type of fatty acids consumed in the diet may impact 24-hour energy expenditure. However, energy expenditure is often measured for a short period of time (30 minutes to a couple of hours) and then extrapolated to 24h measures. We wanted to see if a high-fat diet that was rich in either mono-unsaturated fats or saturated fats would differentially affect 24h energy expenditure. We studied these diets in 8 healthy males under both sedentary and exercise treatments. Each treatment was 5 days in length and they spent 5 days/6 nights in a metabolic chamber where we could measure 24h energy expenditure for several consecutive days. We did not find a difference in 24h energy expenditure from the high mono-unsaturated versus high saturated fat diet. This was different from previous studies, however, we measured energy expenditure rather than calculating or extrapolating from short-term measures. Therefore, it appears that the type of dietary fatty acid does not differentially affect 24h energy expenditure.

Although debated, it’s believed by many that diets rich in saturated fats compared to unsaturated fats increase chronic disease risk factors (for example, cholesterol and blood pressure). Most of the studies showing this have examined long-term diets (12 weeks in length up to several years). We decided to see if just 4 days of a high mono-unsaturated or saturated fat diet could alter chronic disease risk profiles. The results were quite interesting. We found that 4 days of a high saturated fat diet led to significant increases in total and LDL cholesterol, and systolic and diastolic blood pressure. Conversely, the high mono-unsaturated fat diet did not change blood pressure but did decrease total and LDL cholesterol. This means that altering one’s diet for even a few days can have an impact on blood cholesterol and blood pressure measures that may be detrimental to one’s health.

In another one of your more recent research articles, you examine how leptin levels are affected in obese males during over and underfeeding³. Could you briefly explain the function of leptin, how it’s impacted by diet and the results your study found.

Leptin is a hormone that was discovered in 1994 and plays an important role in energy balance. It is released primarily by white adipose tissue (with small amounts also being released from the GI tract) and circulates in proportion to the amount of fat mass present. It acts as a satiety signal for the brain. Higher leptin levels will signal the brain to decrease energy intake (food intake) and increase energy expenditure. Conversely, low leptin levels will stimulate food intake and decrease energy expenditure. When Leptin was first discovered, it was thought that people were possibly deficient in leptin and that it would be the big cure for human obesity. However, only a couple of people in the entire world are leptin deficient. Therefore, overweight or obese individuals who have more fat mass also secrete higher levels of leptin. Since this discovery, it has been proposed that people may develop a resistance to leptin much like insulin resistance in people with type II diabetes mellitus. Research in this area is still ongoing.

In our manuscript, obese males who were underfed (received 70% of total daily energy needs), significantly decreased leptin levels. This was an expected response as lower leptin levels would be signaling the brain to increase energy intake and decrease expenditure. Conversely, when those subjects were overfed (received 130% of total daily energy needs) our results were different than expected. In the subjects who had been underfed for 3 days prior to the overfeeding period, leptin levels increased as expected during overfeeding. However, if those subjects who were not underfed first, overfeeding did not raise leptin levels. This indicated some disregulation as leptin levels should increase during overfeeding (that is what happened in a similar study in lean male subjects). Therefore, overfeeding in overweight or obese individuals may not result in an appropriate leptin response and could lead to increased energy intake and susceptibility to future weight gain.

While on the topic of over/under feeding and obesity, TIME magazine (CLICK HERE) recently published an article that gained a lot of attention in the media⁴. According to the article, the author states that exercise is pointless with respect to weight loss because individuals will compensate for additional exercise by eating more. What’s your take on encouraging exercise as part of a weight loss program?

The author of that article brings up an important point, but I disagree with the thought that exercise is pointless for weight loss. It is true that if caloric intake is increased and matches the increase in energy expenditure then exercise will not result in weight loss. However, most people who lose weight will in some way shape or form restrict their caloric consumption, and this is no different if exercise is incorporated into a weight loss program. If a person wants to lose 1 pound of fat a week, they need to expend approximately 3500 kilocalories (kcals) more than they are consuming. They can either decrease caloric intake by 500kcals a day, increase expenditure by 500kcals a day, or do a combination of increased expenditure and decreased intake. People may feel hungrier if they exercise because of the increased expenditure, but as long as they don’t consume as many kcals as they expended, they will still lose weight. Another important point is that resting metabolism increases as fat free mass increases. Therefore, someone who puts on muscle mass through an exercise program will be burning more kcals at rest and throughout the day which can aid in weight loss.

Curious… once a research team has gathered all of its data, how long does it generally take before it will appear in a research publication? Is it a pretty difficult process to get something published?

The time it takes to get an article published can vary greatly. In general, once all the data has been collected from a study, the data must be analyzed and then the manuscript written. The amount of time this takes depends on how quickly the researcher can get all of this done along with their other responsibilities (can take anywhere from 1 month up to 1 year). Once the manuscript is written, it is submitted to the author’s journal of choice. Upon submission, the editor of the journal will find some scientists who are experts in the field to review the manuscript. There are typically 2 or 3 reviewers per manuscript. Once they reviewers have made all their comments/critiques, the author will be given a few choices:

• 1. The manuscript was not considered worthy of publication in the journal. If this is the case, they author must submit to a different journal and start the whole review process over again.

• 2. The manuscript needs major revisions before being re-submitted for publication consideration, or

• 3. The manuscript needs minor revisions and will then be accepted for publication.

Of course, all authors want the third option. Once all the reviewer’s comments have been adequately addressed, the manuscript is likely accepted for publication. This entire submission and review process can take several months and then it can be several additional months before the manuscript will appear in the journal. I guess to summarize all this, it is not a quick process and probably takes anywhere from a few months to more than a year to get a finished research project published.

I’ve tried to stress to my readers that not all research is good research. Some scientific journals are more stringent than others with respect to the quality of articles they will publish. In your opinion, what are you favorite nutrition/exercise/sports nutrition journals that you enjoy reading? Who are the big names/researchers in sports nutrition or exercise that have made an impression on you?

There are several good journals out there, but many people in the nutrition and/or exercise field publish much of their research in the American Journal of Clinical Nutrition (AJCN), Metabolism, American Journal of Physiology (AJP), Journal of Applied Physiology (JAP), Obesity, and Medicine and Science in Sports and Exercise (MSSE). Of course, there are others, especially depending on what area or topic the manuscript is covering. As far as “big names” in the research field, it’s difficult to say. There are so many specialities within the nutrition and exercise field and within each of those specialities there are always a couple of experts. I guess the best way to check is to look up an author’s publication history or search for a topic of interest and see which people seem to be publishing in the best journals within that topic.

Enough on research. Let’s talk about sports nutrition. What led you to get so involved in this field? An undergraduate degree is one thing, but a MASTERS & DOCTORATE DEGREES!?!? Now that’s impressive!!!

I’ve always been interested in both exercise/sports and nutrition. The two fields just seem to mesh well together as I find them equally important for overall health and optimal athletic performance. I enjoy both teaching and research and knew that I would need to get a PhD in order to do both of those things. I also found that the more I learned about nutrition and exercise, the hungrier I got for more knowledge in each of those areas. That’s one of the great things about teaching and research. I am constantly learning in my job and I get to apply what I learn to my own personal training and athletic events that I enjoy competing in.

That leads me into my next question. I’m sure you’ve probably “Carb Loaded” a few times before your big races to maximize your glycogen stores. [For those not familiar with carbohydrate loading, it’s a technique used to maximize your body’s carbohydrate stores (glycogen). By maximizing your glycogen stores, one can exercise at a higher intensity. Remember, as mentioned in one of my previous articles, glucose is required to exercise at high intensities and also to metabolize fat at lower intensities]. Can you briefly explain the various carbohydrate loading techniques and if you’ve used them both, which one you prefer?

I have done carbo/glycogen loading a couple of times before marathons. I have used two different methods and found that each one seems to work pretty well (led to my 2 fastest marathon times). One method is Astrand’s glycogen loading. For this method, you do an exhaustive bout of exercise 7 days before the event to deplete glycogen levels⁵. For the next 3 days, you eat a low carbohydrate diet (lots of protein and fats) while gradually decreasing your training load. Then for the 3 days leading up to the race, you switch over to a high carbohydrate diet and further decrease training load to maximize glycogen stores. The other method is Sherman’s glycogen loading⁶. The biggest difference between this and Astrand’s method is that with Sherman’s method, you don’t go on a low carbohydrate diet 3-6 days out from the race. Instead you maintain an average carbohydrate intake (about 55% of total energy). Then for the final 3 days before the race, you switch to the high carbohydrate diet just like with Astrand’s method. As I mentioned, I think both methods work. I prefer Sherman’s method because as an endurance athlete I’m used to consuming a fairly high carbohydrate diet. Going on the low carbohydrate diet makes me feel sluggish, tired, irritable, and I usually have a headache for 3 straight days!

With the Sherman method, do they have any recommendations with respect to the training side of things… Kind of like the Astrand method recommending an exhaustive bout of exercise 7 days out?

Sorry, I should have been clearer on this. The exercise recommendations for the Sherman method are the same as the Astrand method. Perform an exhaustive bout of exercise about 7 days prior to the race in order to sufficiently deplete glycogen stores and then a slightly lower volume of training for the next 3 days. The final 3 days leading up to the race should be very low volume of exercise in order to maximize glycogen stores.

When one’s carbohydrate stores are completely used up, they’re forced to rely on fat as basically the main source of energy. This has been referred to as “hitting the wall” or “bonking.” Once this happen, one’s pace has been known to come to an almost complete standstill. Many endurance often consume energy gels/liquids to prevent this from occurring.

Have you ever “hit the wall” or bonked? If so, can you explain what it felt like?

I have “hit the wall” one time during a marathon. It was my first marathon and I was 18 years old. I knew virtually nothing about good nutrition or nutrition for endurance events. I consumed only water during the race because I had never practiced with sports drinks or any other food/beverage. By about mile 20, I was completely tapped out. I struggled through the last 6 miles with a mixture of walking and jogging. I like to think that I learned a hard, but valuable, lesson that day. I am now very careful about my training and race-day nutrition and haven’t “hit the wall” since!

Following an event like a marathon or triathlon what nutrition, physical modalities (ice bath, contrast bath, etc) or rest protocols have you found helpful in your recovery? Do you find that it takes significantly longer to recover from a triathlon vs. a marathon?

Following any endurance event, I usually try to do light stretching every couple of hours and I use some sort of anti-inflammatory to help reduce muscle soreness. I have used an ice bath a couple of times (not my favorite thing, but I think it does work). For the week after a marathon or Ironman, I usually take it pretty easy. I try to do some swimming, biking or other form of cross training each day and I don’t run for about a week or so. Each race affects the body differently so recovery time varies between events. It usually takes me longer to recover from an Ironman than a marathon. However, that’s not always the case. I took more time off after the Boston Marathon because it involves so much downhill running (eccentric movement) and I was sorer from that than any other race I had done. No matter what the race is, I just try to listen to my body and not push it too much before I’m close to reaching full recovery.

That’s all the questions we have today. Thanks again for your time. On behalf of the readers here at CasePerformance, I’d like to wish you success on future research projects and athletic endeavors.

References

¹ Cooper JA, Nagelkirk PR, Coughlin, AM, Womack CJ. Med Sci Sports Exerc. 2004 Nov;36(11): 1884-7. Temporal changes in tPA and PAI-1 following maximal exercise.

² Cooper JA, Watras AC, Adams AK, Schoeller DA. Am J Clin Nutr. 2009 May;89(5):1350-6. Epub 2009 Mar 25.Effects of dietary fatty acid composition on 24-h energy expenditure and chronic disease risk factors in men.

³ Cooper JA, Polonsky KS, Schoeller DA.Serum Leptin Levels in Obese Males During Over- and Underfeeding. Obesity (Silver Spring). 2009 May 14. [Epub ahead of print].

⁴ Cloud J. Why Exercise Won’t Make You Thin. Time. Aug. 09, 2009. Accessed on November 22, 2009 from: http://www.time.com/time/printout/0,8816,1914857,00.html.

⁵ Karlsson, J., and B. Saltin. Diet, muscle glycogen, and endurance performance. J. Appl. Physiol. 31:203Y206, 1971.

⁶ Sherman, W.M., D.L. Costill, W.J. Fink, and J.M. Miller. Effect of exercise-diet manipulation on muscle glycogen and its subsequentutilization during performance. Int. J. Sports Med. 2:114Y118,1981.