Triathlon and Swimming Economy I

We wrote about triathlon and running economy, but there is a swimming economy.  “Swimming with the body” instead of swimming with your arms and legs; same thing for running, we should maximize the use of gravity when running instead of running with the legs.  It is more economical; and above all, it is economical when going fast.  We need to be economical when going fast in today’s world.  It is the SWAT karma: “It is not only well-done and precise but fast.”

Science is not a democracy, so there are ways to do things that have more advantages than others.  There is a way of doing things well and efficiently. Furthermore, technique can improve all the time as it is shown in the video below.  The video claimed that there is an individual technique for each individual.  We should know that swimming technique is just one and we can adapt it to individuals depending on their circumstances and the individual’s capacity to learn. ¿Is a Paralympic swimmer? Every individual can improve his/her technique, but it can take years to see the difference.  We can see the following swimmer with the swimmer’s head lifted; he can improve by looking at the bottom of the pool but it would change the entire stroke and perhaps it is not worth it considering time, effort, and where he is competitively at the present time.  It is very important to know Physics in order to start swimming, considering the body position, drag (including kicking and pulling) or support, under Physics’ premises.  Remember from previous post on running economy, we have to know the variables playing a role swimming; we should not accept that things could not be improved.  At the end, swimming can be interpreted with basic Newtonian Physics in order to have full advantage of the vectors that works on the stroke and resistance of the water.

After what it was said, let’s look at videos.  

1) The number of strokes does not change with speed.

2) The speed of doing the stroke is the only thing that changes.

3) Open water swimming needs more concentration to perform as well as in the swimming pool.

4) In the Olympics finals, the number of strokes for the first eight swimmers. The number of strokes is the same less than 35 strokes per 50 meters for males when going more than 200 meters.

Triathlon and Running Economy IV

We discussed how research has been done and the confounding variables that exist in the three previous posts.  Let´s look at how the Japanese try to do research on running in the following video.  We can come up with valid data useful for our triathletes:

1)   Touching the ground less than 0.16 of a second.

2)   The weight of the subject when touching the ground is less than 50% of the total when touching the ground, meaning that the weight is dependent on the time touching the ground.  The Japanese runner stays on the ground longer (0.22), so his weight is higher than 80% of the total.

3)   The time on the ground limits the elasticity and the energy stored in the muscles and tendons is wasted.

4)   The weight is a big factor in our performance.  It is easier to increase cadence in our practice than to trim a triathlete when talking about running economy.

Practicing technique will direct the needed structure.

Triathlon and Running Economy III

We have written on what it is confounding variables; nonetheless we came up short.  An article written in www.medscape.org helps to understand this subject better.  We just copied the introduction for you.  Unfortunately, the running research is full of confounding variables due to the complexity of running.

How Do You Know Which Health Care Effectiveness Research You Can Trust? A Guide to Study Design for the Perplexed CME

Stephen B. Soumerai, ScD; Douglas Starr, MS; Sumit Majumdar, MD, MPH, FRCPC

Editor’s Note: The purpose of this Editor’s Choice article is translational in nature. It is intended to illustrate some of the most common examples of potential study bias to help policy makers, journalists, trainees, and the public understand the strengths and weaknesses of various types of healthcare research and the kinds of study designs that are most trustworthy. It is neither a comprehensive guide nor a standard research methods article. The authors intend to add to these examples of bias in research designs in future brief and easy-to-understand articles designed to show both the scientific community and the broader population why caution is needed in understanding and accepting the results of research that may have profound and long-lasting effects on health policy and clinical practice.

Evidence is mounting that publication in a peer-reviewed medical journal does not guarantee a study’s validity.^[1]Many studies of healthcare effectiveness do not show the cause-and-effect relationships that they claim. They have faulty research designs. Mistaken conclusions later reported in the news media can lead to wrong-headed policies and confusion among policy makers, scientists, and the public. Unfortunately, little guidance exists to help distinguish good study designs from bad ones, the central goal of this article.

There have been major reversals of study findings in recent years. Consider the risks and benefits of postmenopausal hormone replacement therapy (HRT). In the 1950s, epidemiological studies suggested higher doses of HRT might cause harm, particularly cancer of the uterus.^[2] In subsequent decades, new studies emphasized the many possible benefits of HRT, particularly its protective effects on heart disease — the leading killer of North American women. The uncritical publicity surrounding these studies was so persuasive that by the 1990s, about half the postmenopausal women in the United States were taking HRT, and physicians were chastised for under-prescribing it. Yet in 2003, the largest randomized controlled trial (RCT) of HRT among postmenopausal women found small increases in breast cancer and increased risks of heart attacks and strokes, largely offsetting any benefits such as fracture reduction.^[3]

The reason these studies contradicted each other had less to do with the effects of HRT than the difference in studydesigns, particularly whether they included comparable control groups and data on preintervention trends. In the HRT case, health-conscious women who chose to take HRT for health benefits differed from those who did not — for reasons of choice, affordability, or pre-existing good health.^[4] Thus, although most observational studies showed a “benefit” associated with taking HRT, findings were undermined because the study groups were not comparable. These fundamental nuances were not reported in the news media.

Another pattern in the evolution of science is that early studies of new treatments tend to show the most dramatic, positive health effects, and these effects diminish or disappear as more rigorous and larger studies are conducted.^[5]As these positive effects decrease, harmful side effects emerge. Yet the exaggerated early studies, which by design tend to inflate benefits and underestimate harms, have the most influence.

Rigorous design is also essential for studying health policies, which essentially are huge real-world experiments.^[1]Such policies, which may affect tens of millions of people, include insurance plans with very high patient deductible costs or Medicare’s new economic penalties levied against hospitals for “preventable” adverse events.^[6] We know little about the risks, costs, or benefits of such policies, particularly for the poor and the sick. Indeed, the most credible literature syntheses conducted under the auspices of the international Cochrane Collaboration commonly exclude from evidence 50% to 75% of published studies because they do not meet basic research design standards required to yield trustworthy conclusions (eg, lack of evidence for policies that pay physicians to improve quality of medical care).^[7,8]

This article focuses on a fundamental question: which types of healthcare studies are most trustworthy? That is, which study designs are most immune to the many biases and alternative explanations that may produce unreliable results?^[9] The key question is whether the health “effects” of interventions — such as drugs, technologies, or health and safety programs — are different from what would have happened anyway (ie, what happened to a control group). Our analysis is based on more than 75 years of proven research design principles in the social sciences that have been largely ignored in the health sciences.^[9] These simple principles show what is likely to reduce biases and systematic errors. We will describe weak and strong research designs that attempt to control for these biases. Those examples, illustrated with simple graphics, will emphasize 3 overarching principles:

1. No study is perfect. Even the most rigorous research design can be compromised by inaccurate measures and analysis, unrepresentative populations, or even bad luck (“chance”). But we will show that most problems of bias are caused by weak designs yielding exaggerated effects.
2. “You can’t fix by analysis what you bungled by design”.^[10] Research design is too often neglected, and strenuous statistical machinations are then needed to “adjust for” irreconcilable differences between study and control groups. We will show that such differences are often more responsible for any differences (effects) than is the health service or policy of interest.
3. Publishing innovative but severely biased studies can do more harm than good. Sometimes researchers may publish overly definitive conclusions using unreliable study designs, reasoning that it is better to have unreliable data than no data at all and that the natural progression of science will eventually sort things out. We do not agree. We will show how single, flawed studies, combined with widespread news media attention and advocacy by special interests, can lead to ineffective or unsafe policies.^[1]

The case examples in this article describe how some of the most common biases and study designs affect research on important health policies and interventions, such as comparative effectiveness of various medical treatments, cost-containment policies, and health information technology.

The examples include visual illustrations of common biases that compromise a study’s results, weak and strong design alternatives, and the lasting effects of dramatic but flawed early studies. Generally, systematic literature reviews provide more conservative and trustworthy evidence than any single study, and conclusions of such reviews of the broad evidence will also be used to supplement the results of a strongly designed study. Finally, we illustrate the impacts of the studies on the news media, medicine, and policy.

Triathlon and Running Economy II

We wrote an article regarding running economy.

2 sept. 2015

Triathlon and Running Economy

After the previous post, we looked into the economy of running from the point of view of a researcher and not of a coach.  Researchers continue to struggle with the ECONOMY OF RUNNING.  Variables are many and they are not considered as variables most of the time.  We have problems to have models to study economy of running because we are unable to see athletes; we just study theories instead of looking at athletes or plain and simple technique models.  Researchers translate technique in a simpler way, when technique encompasses multiple variables itself and it is impossible to break it down as it has been done by researchers.  It is like a word in a language that cannot be translated because of its multiple meanings.   Albert Einstein said it and started looking at the phenomenon instead of playing with the theories:

Everything should be made as simple as possible, but not simpler.

If, then, it is true that the axiomatic basis of theoretical physics cannot be extracted from experience but must be freely invented, can we ever hope to find the right way? I answer without hesitation that there is, in my opinion, a right way, and that we are capable of finding it. I hold it true that pure thought can grasp reality, as the ancients dreamed. (Albert Einstein, 1954)

It should be explained in a simple way but not simpler, as Albert Einstein said. We looked into the cost of running, actually while running. There are good attempts to study running while running which consider technique, and especially foot ground contact:

http://www.academia.edu/5255658/DIFFERENCES_IN_GROUND_CONTACT_TIME_EXPLAIN_THE_LESS_EFFICIENT_RUNNING_ECONOMY_IN_NORTH_AFRICAN_RUNNERS

Elite North African runners have performed outstandingly on the track at international athletic events. Despite the high level of runners participating in this study, a possible limitation was that they were 3-4 minutes slower than athletes of an Olympic standard. A question arises whether the physiological and biomechanical responses of the pace in North African runners implies that their outstanding performance on the track at international athletic events appears not to be linked to running efficiency. The differences in metabolic demand at increased velocity were found to be associated with differing biomechanical running patterns. 

The ground contact is faster in faster runners; the winners.  The authors need to study champions for a comparison.  The authors found foot ground contact as the only difference for the best running economy and this is very simple to understand.  We assume that the energy store in our muscles and tendons is the most important variable to keep running.

http://jeb.biologists.org/content/204/10/1805.full.pdf

 Our success in linking metabolic cost to whole-body mechanics suggests that this approach has potential to further advance the understanding of the relationship between the mechanical activity of the musculoskeletal system and the energetic cost of movement in general. Finally, we conclude that metabolic rates during running are determined by the time course of muscular activation and the volume of muscle recruited to apply support forces against the ground.

Technique implies that the center of gravity is in front of the subject, foot ground contact as short as possible, utilization of energy to move us forward instead of using the energy to lift the body weight.

I leave you with a good presentation and a question: ¿Could you find the confounding variables?  Technique and physical structure are complementary and belong to different languages.  Practice technique and the physical structure will come with time; many years later.