Name: Determining the Contribution of the Energy Systems During Exercise (Video) | JoVE Journal
Uploaded: 2012-03-20T12:00:00.000+00:00
Duration: 11 min 15 s
Description: Learn how to determine energy system contributions during exercise using portable gas analyzers and mathematical modeling. This computational method quantifies aerobic, lactic, and anaerobic metabolism in unpredictable sports like judo.

ai_agent_IP

ai_agent

maintenance

instantTrialDurationMinutes

isBiopharma

enableNewMyJoveSectionDesign

educationFeatures

seoMetaApi

ai_copilot_institution_blacklist

ai_chat_institution_blacklist

freeAccessWindow

ssoRoleCapture

scheduledMaintenanceBanner

joveLabsFeatures

disable_autoplay_for_bots

extended_trial_duration

5 minutes

We thank to Fabiana Benatti for her kind cooperation in the video. We also thank FAPESP (#2007/51228-0) and CNPq (#300133/2008-1) for the support to our researches on this area.

Introduction
The energy necessary for sustaining a physical effort comes from two metabolic sources: aerobic and anaerobic metabolism. While the aerobic metabolism is more efficient than the anaerobic metabolism (i.e., it produces a higher amount of ATP per mol of substrate), producing energy through anaerobic metabolism can provide a high amount of energy in a very short time period. This may be decisive for any situation that requires extremely fast movements. 
Each sport has specific characteristics in terms of motor skills that confer unique physiologic and metabolic demands for that particular sport. The most important aspect of the metabolic demand is the relative contribution of the energy systems to the total energy required for the activity. To determine the specific demand of each sport is crucial for developing optimized training models, nutritional strategies and ergogenic aids that may maximize athletic performance.
Some sports are relatively easy to be reproduced in a laboratory setting, thus it is possible to create a controlled environment in which athletes can be evaluated. This is the case of running and cycling, for example. Predictable movements compose these sports and, therefore, they are easy to be studied. Using some simple equipment, it is possible to mimic quite exactly the same movements that athletes perform in real situations, such as training and competitions. Indeed, these sports have been more extensively studied by exercise scientists and benefited with a more complete and reliable scientific literature. 
On the other hand, a number of sports are much more difficult to be reproduced in laboratory. These sports are unpredictable and dependent on the actions of the partner(s) and opponent(s). This leads to an inability to accurately reproduce the competitive conditions in the lab and an inability to assess these athletes in field during either training or competition. Maybe because of these problems, they have received much less attention from the scientists. This is the case of the majority of team sports and many individual sports1.
Considering these aspects, we aimed to describe how to assess the differential contribution of the energy systems in sports that are difficult to reproduce in controlled laboratory conditions. Because judo is a very complex and unpredictable sport, we will use judo as an example. However, the concepts shown here can be adapted to a number of different sports.
1. Physiological Measurements at Rest
<ol>
 <li>Measure the athlete’s body mass before he/she initiates exercising.</li>
 <li>Before initiating the exercise, collect a small resting blood sample from earlobe or fingertip and keep it on ice until the whole experimental procedure is finished.</li>
 <li>Following, place the calibrated portable gas analyser at the most convenient position, which depends on the movements that the athlete will perform, and record resting or baseline oxygen consumption for five minutes. During the baseline measurement, the athlete has to stay quiet standing on his/her feet (if the exercise will be performed in a standing position) or sat in the equipment that will be used (if the exercise will be performed in a cycloergometer or in any similar equipment).</li>
</ol>
2. Physiological Measurements during Exercise
<ol>
 <li>After collecting resting blood sample and resting oxygen consumption, you may ask the athlete to start the specific exercise that you are studying. The portable gas analyser has to be placed in a position that will no interfere with exercise and that exercise will not damage the equipment. Continue measuring oxygen consumption throughout the exercise period.</li>
</ol>
3. Physiological Measurements after Exercise
<ol>
 <li>After collecting exercise oxygen consumption data, keep recording oxygen consumption for ten minutes before shutting the equipment down. Always recalibrate the gas analyser if more than one athlete is being evaluated in the same day.</li>
 <li>In order to identify the peak plasma lactate after exercise, collect small blood samples immediately after exercise, three, five and seven minutes after exercise. Keep them on ice until analysis.</li>
</ol>
4. Blood Samples Processing and Peak Plasma Lactate Determination
<ol>
 <li>All blood samples must be placed in microtubes containing a similar volume of a 2% NaF solution (i.e., if you are collecting 25 μL of blood, place it in 25 μL of 2% NaF).</li>
 <li>When data collection is finished, separate plasma from erythrocytes by spinning the samples for 5 minutes at 2000 g at 4°C.</li>
 <li>Plasma lactate can be determined through a variety of methods2,3. In our lab, we use the electrochemical method with the aid of an automatized lactate analyser (Yellow Springs 1500 Sport, Ohio).</li>
</ol>
5. Calculations
<ol>
 <li>Calculate the net energy generated by the aerobic metabolism by subtracting rest oxygen consumption from exercise oxygen consumption. Oxygen consumption at rest is obtained by multiplying the average of the last 30 seconds of baseline oxygen consumption by the total exercise duration time. Then, calculate the area under the curve of exercise oxygen consumption by using the trapezoidal method. Finally, subtract the resting oxygen consumption from exercise oxygen consumption.</li>
 <li>The contribution of the anaerobic alactic metabolism (i.e., the ATP-CP pathway) can be considered as the fast component of excess post-exercise oxygen consumption4-6, as illustrated in Figure 1. Calculate the energy produced by the alactic system by fitting the kinetics of post-exercise oxygen consumption to a bi- or a monoexponential curve. This can be done with the aid of mathematics' software (e.g. Microcal Origin version 7.0). Choose by the mono- or bi-exponential curve based on the model that best fits to your data set (i.e., the lowest residue). Then, use the terms provided by the fitted equation (Equation 1) to calculate alactic contribution according to Equation 2. 
 <img src="/files/ftp_upload/3413/3413fig1.jpg" alt="VO2 vs. time graph; exercise and post-exercise phases; fast, slow components; physiological response." data-altupdatedat="1788304762000" data-alt="Fiugre 1"> 
 Figure 1. Schematic illustration of a typical oxygen consumption curve obtained at rest, during, and after exercise. 
 Equation 1: 
 <img src="/files/ftp_upload/3413/3413eq1.jpg" alt="oxygen uptake equation; exponential model for VO2 response; formula analysis" data-altupdatedat="1788304762000" data-alt="Equation 1"> 
 Equation 2: 
 <img src="/files/ftp_upload/3413/3413eq2.jpg" alt="Alactic contribution formula: A1 • τ1. Equation for physiological process study." data-altupdatedat="1788304762000" data-alt="Equation 2"> 
 where VO2(t) is oxygen uptake at time t, VO2baseline is oxygen uptake at baseline, A is the amplitude, δ is the time delay, τ is a time constant, and 1 and 2 denote the fast and slow components, respectively.</li>
 <li>To calculate the contribution of the lactic anaerobic system, it is assumed that 1 mM of lactate above the resting values corresponds to 3 mL of oxygen consumed per kilogram of body mass7. Thus, calculate delta peak plasma lactate (i.e., peak plasma lactate minus resting plasma lactate) and multiply it by 3 and by the athlete’s body mass. The obtained value of oxygen in mL is then converted to L and to energy (kJ), assuming that each 1 L of O2 is equal to 20.92 kJ.</li>
 <li>Finally, the result obtained by each energy system is summed so you have the total energy expenditure during the activity and the relative contribution of each of system can be calculated.</li>
</ol>
6. Representative Results
Figure 2 depicts a representative curve of oxygen consumption at rest, during exercise and after exercise. In the example used here, athletes performed three different judo techniques (o-uchi-gari, harai-goshi and seoi-nage) for five minutes (one throw every 15 s)8. This is a typical response to intermittent exercise. After the calculations, we obtained the final results on the contribution of the energy systems during judo exercises (Table 1).
Additional representative results are displayed in Table 2. In this example, indoor rock climbers of different competitive levels (i.e., recreational vs. elite) were assessed during a low-difficulty climb route. Individual results for one elite athlete and one recreational athlete are shown (Table 2).
<table border="1">
 <tbody>
 <tr>
 <td rowspan="2"> </td>
 <td colspan="2">Seoi-nague</td>
 <td colspan="2">Harai-goshi</td>
 <td colspan="2">O-uchi-gari</td>
 </tr>
 <tr>
 <td>kJ</td>
 <td>%</td>
 <td>kJ</td>
 <td>%</td>
 <td>kJ</td>
 <td>%</td>
 </tr>
 <tr>
 <td>Anaerobic alactic</td>
 <td>46 ± 20</td>
 <td>16.3 ± 2.8</td>
 <td>43 ± 21</td>
 <td>16.1 ± 2.7</td>
 <td>36 ± 22</td>
 <td>14.6 ± 2.8</td>
 </tr>
 <tr>
 <td>Aerobic</td>
 <td>223 ± 66</td>
 <td>82.2 ± 2.9</td>
 <td>211 ± 66</td>
 <td>82.3 ± 3.8</td>
 <td>196 ± 74</td>
 <td>84.0 ± 3.8</td>
 </tr>
 <tr>
 <td>Anaerobic lactic</td>
 <td>4 ± 2</td>
 <td>1.5 ± 0.7</td>
 <td>5 ± 5</td>
 <td>1.6 ± 1.4</td>
 <td>4 ± 4</td>
 <td>1.5 ± 1.1</td>
 </tr>
 <tr>
 <td>Total</td>
 <td>273 ± 86</td>
 <td> - </td>
 <td>259 ± 91</td>
 <td> - </td>
 <td>237 ± 99</td>
 <td> - </td>
 </tr>
 <tr>
 <td>Total (kJ/min)</td>
 <td>51.9 ± 8.7</td>
 <td> - </td>
 <td>49.4 ± 8.9</td>
 <td> - </td>
 <td>45.3 ± 19.6</td>
 <td> - </td>
 </tr>
 </tbody>
</table>
Table 1. Representative results of total energy expenditure and the contribution of the energy systems during three different judo exercises.
<table border="1">
 <tbody>
 <tr>
 <td>Competitive Level</td>
 <td>Aerobic (%)</td>
 <td>Anaerobic Lactic (%)</td>
 <td>Anaerobic Alactic (%)</td>
 <td>Total (kJ)</td>
 <td>Total (kJ/s)</td>
 </tr>
 <tr>
 <td>Elite</td>
 <td>40</td>
 <td>8</td>
 <td>52</td>
 <td>70.4</td>
 <td>1.00</td>
 </tr>
 <tr>
 <td>Recreational</td>
 <td>40</td>
 <td>15</td>
 <td>45</td>
 <td>96.1</td>
 <td>1.15</td>
 </tr>
 </tbody>
</table>
Table 2. Representative individual data of total energy expenditure and the contribution of the energy systems during a low-difficulty climb route.
<img src="/files/ftp_upload/3413/3413fig2.jpg" alt="VO2 kinetics graph of judo techniques, VO2 vs. time, illustrating aerobic demand analysis." data-altupdatedat="1788304762000" data-alt="Figure 2"> 
Figure 2. Representative results obtained during a 5-minute judo exercise.

<ol><li>Franchini, E., Del Vecchio, F. B., Matsushigue, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Physiological+profiles+of+elite+judo+athletes%5BTitle%5D)+AND+%22Sports+Med%22%5BJournal%5D)">Physiological profiles of elite judo athletes.</a> Sports Med. 41, 147-166 (2011).</li>
<li>Bergmeyer, H. U., Bergmeyer, J., Grassl, M. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aBergmeyer%2C+HU+%22Methods+of+enzymatic+analysis%22">Methods of enzymatic analysis</a>. , Academic Press. New York. (1983).</li>
<li>Passonneau, J. V., Lowry, O. H. Enzymatic Analysis. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aPassonneau%2C+JV+%22A+Practical+Guide%22">A Practical Guide</a>. , Humana Press. Totowa, New Jersey. (1993).</li>
<li>Beneke, R., Pollmann, C., Bleif, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((How+anaerobic+is+the+Wingate+Anaerobic+Test+for+humans%5BTitle%5D)+AND+%22Eur.+J.+Appl.+Physiol%22%5BJournal%5D)">How anaerobic is the Wingate Anaerobic Test for humans.</a> Eur. J. Appl. Physiol. 87, 388-392 (2002).</li>
<li>Beneke, R., Beyer, T., Jachner, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Energetics+of+karate+kumite%5BTitle%5D)+AND+%22Eur.+J.+Appl.+Physiol%22%5BJournal%5D)">Energetics of karate kumite.</a> Eur. J. Appl. Physiol. 92, 518-523 (2004).</li>
<li>Bertuzzi, R. C. D., Franchini, E., Kokubun, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Energy+system+contributions+in+indoor+rock+climbing%5BTitle%5D)+AND+%22Eur.+J.+Appl.+Physiol%22%5BJournal%5D)">Energy system contributions in indoor rock climbing.</a> Eur. J. Appl. Physiol. 101, 293-300 (2007).</li>
<li>di Prampero, P. E., Ferretti, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+energetics+of+anaerobic+muscle+metabolism%3A+a+reappraisal+of+older+and+recent+concepts%5BTitle%5D)+AND+%22Respir.+Physiol%22%5BJournal%5D)">The energetics of anaerobic muscle metabolism: a reappraisal of older and recent concepts.</a> Respir. Physiol. 118, 103-115 (1999).</li>
<li>Franchini, E., Bertuzzi, R. C. D., Degaki, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Energy+Expenditure+in+Different+Judo+Throwing+Techniques.+Proceedings+of+first+joint+international+pre-Olympic+conference+of+sports+science+and+sports+engineering%2C+vol+II%5BTitle%5D)+AND+%22Bio-mechanics+and+sports+engineering%22%5BJournal%5D)">Energy Expenditure in Different Judo Throwing Techniques. Proceedings of first joint international pre-Olympic conference of sports science and sports engineering, vol II.</a> Bio-mechanics and sports engineering. , 55-60 (2008).</li>
<li>Calmet, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Developing+ecological+research+in+judo%5BTitle%5D)+AND+%22Percept.+Mot.+Skills%22%5BJournal%5D)">Developing ecological research in judo.</a> Percept. Mot. Skills. 105, 646-648 (2007).</li>
<li>Mello, F. D., Bertuzzi, R. C., Grangeiro, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Energy+systems+contributions+in+2%2C000+m+race+simulation%3A+a+comparison+among+rowing+ergometers+and+water%5BTitle%5D)+AND+%22+Eur.+J.+Appl.+Physiol%22%5BJournal%5D)">Energy systems contributions in 2,000 m race simulation: a comparison among rowing ergometers and water.</a> Eur. J. Appl. Physiol. 105, 615-619 (2009).</li>
<li>Bertuzzi, R. C., Franchini, E., Ugrinowitsch, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Predicting+MAOD+using+only+a+supramaximal+exhaustive+test%5BTitle%5D)+AND+%22Int.+J.+Sports+Med%22%5BJournal%5D)">Predicting MAOD using only a supramaximal exhaustive test.</a> Int. J. Sports Med. 31, 477-481 (2010).</li>
</ol>

The authors declare they have no conflict of interest regarding this study.

The method we have shown hare can be used for both continuous and intermittent exercise. The great advantage of the method is that it can be adapted to exercises and sports that are difficult to be mimicked in controlled laboratory settings. Furthermore, this is the only available method capable of distinguishing the contribution of three different energy systems. Thus, the method allows the study of sports with great similarity to real situations, providing desirable ecological validity to the study9. For example, a recent study by Mello et al.10 showed that the glycolytic contribution in a 2000 m on water rowing race is of only 7%, which means that rowing performance is mainly dependent on the aerobic metabolism. Similarly, a study by Beneke et al.4 confirmed that the main source of energy during one of the most used anaerobic tests, the Wingate Anaerobic Test, is the anaerobic metabolism (20% aerobic; 30% alactic and 50% glycolytic). Recent studies by our group have also characterized the energy contributions of indoor climbing6 and judo8, as reported in this example. Indeed, the knowledge on the energetic contribution is critical for the development of ergogenic strategies, training organization or even for validating a test.
This method has some limitations. First, the cost of the equipment is somewhat high, and specialized trained personnel are required. Second, although most sports can be mimicked with this technique, it is not any type of exercise that can be studied using the portable gas analyzer. Finally, as plasma lactate does not exactly represent the total lactate produced by skeletal muscle during activity, the results obtained by this procedure can be considered as an estimative of the metabolic demand during exercise, rather than a precise quantification of the energetic contribution. Nonetheless, this is the only validated method available11 capable of distinguishing the contribution of the three different energy systems.

<table><tbody><tr><td>YSI 1500 Sport</td><td>Yellow Springs</td><td></td><td>This equipment allows a quick and easy plasma lactate determination</td></tr><tr><td>K4 b2</td><td>Cosmed</td><td></td><td>This equipment is essential for measuring oxygen consumption throughout the exercise</td></tr><tr><td>Software Microcal 6.0</td><td>OriginLab</td><td></td><td>This software (or any other with similar capabilities) will be useful for the calculations</td></tr></tbody></table>

determining the contribution of the energy systems during exercise

Determining the Contribution of the Energy Systems During Exercise

One of the most important aspects of the metabolic demand is the relative contribution of the energy systems to the total energy required for a given physical activity. Although some sports are relatively easy to be reproduced in a laboratory (e.g., running and cycling), a number of sports are much more difficult to be reproduced and studied in controlled situations. This method presents how to assess the differential contribution of the energy systems in sports that are difficult to mimic in controlled laboratory conditions. The concepts shown here can be adapted to virtually any sport.
The following physiologic variables will be needed: rest oxygen consumption, exercise oxygen consumption, post-exercise oxygen consumption, rest plasma lactate concentration and post-exercise plasma peak lactate. To calculate the contribution of the aerobic metabolism, you will need the oxygen consumption at rest and during the exercise. By using the trapezoidal method, calculate the area under the curve of oxygen consumption during exercise, subtracting the area corresponding to the rest oxygen consumption. To calculate the contribution of the alactic anaerobic metabolism, the post-exercise oxygen consumption curve has to be adjusted to a mono or a bi-exponential model (chosen by the one that best fits). Then, use the terms of the fitted equation to calculate anaerobic alactic metabolism, as follows: ATP-CP metabolism = A1 (mL . s-1) x t1 (s). Finally, to calculate the contribution of the lactic anaerobic system, multiply peak plasma lactate by 3 and by the athlete&#x2019;s body mass (the result in mL is then converted to L and into kJ).
The method can be used for both continuous and intermittent exercise. This is a very interesting approach as it can be adapted to exercises and sports that are difficult to be mimicked in controlled environments. Also, this is the only available method capable of distinguishing the contribution of three different energy systems. Thus, the method allows the study of sports with great similarity to real situations, providing desirable ecological validity to the study.

This protocol allows researchers focused on exercise and sports sciences to determine the relative contribution of three different energy systems to the total energy expenditure during a large variety of exercises.

One of the most important aspects of the metabolic demand is the relative contribution of the energy systems to the total energy required for a given ...

Hi, I'm Dr.Emerson Frank. Our group represent how to determine the energy systems in sports that are difficult to be reproduced in control environments such as exercise physiology labs. Each sport has specific characteristics that confer different metabolic demands to them.One of the most important aspects of the metabolic demand is the relative contribution of the energy systems, namely the aerobic, lactic, anaerobic, lactic and aerobic. Some sports can be somewhat easily mimicked in therefore studied in a laboratory setting as they are cyclic and predictable. On the other hand, some sports are unpredictable and dependent on a complex interaction between teammates and or opponents.This is the case that the majority of team sports in a number of individual sports. Here we'll show how the relative contribution of the energy systems can be assessed during exercise. Although the method is suitable to any type of exercise, we'll emphasize its adaptation to unpredictable parts due to its particular characteristics.Judo will be used as an example on how the procedure can be adapted. Depending on the athlete's movements, researches focuses on other sports may easily adapt to the procedure. Based on what is shown here, The following physiological variables will be assessed.Rest, oxygen consumption, exercise, oxygen consumption, post exercise, oxygen consumption, rest plasma lactate, concentration, post exercise, plasma peak lactate. First, a restin blood sample Must be collected and rest oxygen consumption measured for at least five minutes. The oxygen uptake during the last 30 seconds of this period is used to calculate the baseline value and the oxidative metabolism Contribution for blood sample collection is small volume of capillary blood is taken from the ear lobe or from the fingertip after collection placed with the help of a micro ppa, a known volume of the blood in the same volume of a 1%sodium fluoride solution.Exercise.Oxygen consumption has to be measured through the use of a portable gas analyzer. Capable of measuring oxygen consumption on a breath by breath basis. Place the mask and make sure that it is properly sealed so there is no leakage of the expired air.Always calibrate equipment following manufacturer's instructions before data collection. Normally the equipment is placed at the athlete's back. However, in complex sports, the position of the equipment must be adapted using judo.As an example, if the technique requires dorsal contact, the equipment is placed at the chest. If the technique requires frontal contact, the equipment is placed at the back. The same has to be done if the back touches the ground.If the technique requires lateral contact, the equipment is placed at the opposite lateral. With a few adaptations to competition's rules, it is possible to create an exercise in which the athlete is submitted to a very similar demand of the sport. For example, here we simulate a judo combat to avoid any damage to the equipment.The opponent does not apply any effective throw. Also, the athlete being evaluated may not apply any throw that requires dorsal contact. Once the data collection is finished, we'll be ready to start the procedures to calculate the energy contribution.Let's see how to do it. First, plasma lactate has to be measured, spin the blood to separate plasma from erythrocytes. Then plasma lactate can be measured, spectro, photometrically, fluor metrically, or electrochemically.In our lab, we normally use the electrochemical method through an automatized lactate analyzer. The result is immediately shown in a small screen and it then needs to be corrected by The dilution factor. This is a typical curve of oxygen Consumption at rest or baseline during exercise After exercise.Taking a close look at the post exercise curve, it is possible to see two different components. The fast component, the slow component to calculate the contribution of the aerobic metabolism to the total energy spend during exercise, determine the baseline or rest value for oxygen consumption. This can be done by calculating the average of the last 30 seconds of the curve.Then multiply the value obtained by the total time of exercise. For example, if the exercise duration was five minutes, multiply the rest oxygen consumption by five. Determine total oxygen consumption during exercise by calculating the area under the curve of the exercise oxygen consumption.Use the trapezoidal method to calculate area under the curve. Finally, subtract the baseline oxygen consumption from the exercise oxygen Consumption. To calculate the Contribution of the L anaerobic metabolism, the kinetics of the post-exercise curve has to be adjusted to a mono or by exponential model.Using the data obtained in each breath adjusted for a mono exponential curve and for a bio exponential curve. This may be done with the help of a mathematical software. If the exercise you're studying has a unknown curve pattern, then both mono and bio exponential models should be tested to verify, which then best fits to your data.To do so, use the software to generate the mono exponential and the bi exponential adjustments. In the best model, the real curve is closer to the fitted curve. Using the data of the real curve and the fitted curve, calculate the residue of the model for each breath.That is subtract the fitted value from the real value and square the result. After calculating the residue of each point of the curve for both mono and by exponential adjustments test whether the residues are different between the models through the use of the F test. The best model is the one that generated the smallest residue.If there is no significant difference between the models, use the simplest one that is the mono exponential. Finally, use the terms of the equation provided by the best feeded curve to calculate the contribution of the electric metabolism. As an example, this is the equation for the mono exponential adjustment.Used these terms to calculate the anaerobic elastic contribution with the following equation. Amplitude A one has to be divided by 60, so the unit milliliters per minute is converted to milliliters per second. To calculate the contribution of the lactic and anaerobic metabolism, we assume that one millimole of lactate above the resting values corresponds to three milliliters of oxygen consumed per kilogram of body mass.Thus, the delta peak plasma lactate that is peak plasma lactate minus resting plasma lactate is multiplied by three and by the athlete's body mass. The result in milliliters is then converted to liters and in energy, assuming that each liter of oxygen is equal to 20.92 kilojoules. Lastly, the result obtained by each system is summed, so you have the total energy spend during the exercise and relative contribution of each system to the total can be then calculated.The method that we have shown here can be used for both continuous and intermittent exercises. The greater advantage of the method is that it can be adapted to exercises and sports that are difficult to be mimicked in, controlled the laboratory settings. Also, this is the only available method capable of estimating the contribution of the three different energy systems.Thus, this method allows the studio of physiological responses with great similarity to real part situations, providing desirable ecological validity to this study. For example, I studied from Benefit L, confirmed that the main source of the energy during one of the most used anaerobic testis, the wing gauge anaerobic test, is the anaerobic metabolism. More precisely 50%glycolytic, 30%atic, and 20%aerobic.Recent studies by our group have also characterized the energy contributions of indoor rock climbing, rowing, and judo as presented in this example. Indeed, the knowledge of the energetic contribution is critical for the development of genic strategies, training, monitoring, or even for validating a test.

determining-the-contribution-of-the-energy-systems-during-exercise

Research

JoVE Journal

Biology

This protocol describes the electromyographic fatigue threshold which demarcates between nonfatiguing and fatiguing exercise workloads. This information could be used to develop a more individualized training program.

Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test

Here we present a protocol to assess cardiopulmonary function in awake swine, at rest and during graded treadmill exercise. Chronic instrumentation allows for repeated hemodynamic measurements uninfluenced by cardiodepressive anesthetic agents.

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

To assess the pulmonary diffusion and vasculature responses to exercise, we describe the multiple-inspired oxygen diffusion capacity technique to determine capillary blood volume and membrane diffusing capacity, as well as agitated saline contrast echocardiography to assess the recruitment of intrapulmonary arteriovenous anastomoses.

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise

Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess reactive hyperemia, neurovascular coupling and skeletal muscle oxidative capacity in a single clinic or laboratory visit.

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

To assess the influence of exercise intensity on physiologic and biologic responses, two different exercise testing protocols were utilized. Methods outlining exercise testing on a cycle ergometer as an incremental maximal oxygen consumption test and endurance, steady state submaximal endurance test are described.

Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans

Here, we present protocols of high-intensity interval and moderate-intensity continuous exercise to observe the response of circulating cardiac troponin T (cTnT) concentration to acute exercise over 10 days. The information may assist with clinical interpretations of post-exercise cTnT elevation and guide the prescription of exercise.

Impact of High-intensity Interval Exercise and Moderate-Intensity Continuous Exercise on the Cardiac Troponin T Level at an Early Stage of Training

This protocol integrated near-infrared spectroscopy into conventional cardiopulmonary exercise testing to identify the involvement of the cerebral hemodynamic response in exercise intolerance in patients with heart failure.

Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure

As opposed to measurement during free swimming, which presents inherent challenges and limitations, determination of important parameters of cardiorespiratory function for swimmers can be made using a more feasible and easier to administer tethered-swimming rapidly incremented protocol with gas exchange and ventilatory data collection.

A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers

Hydration status imbalances can have a short-term effect on direct and indirect determinants of oxygen uptake and pulse, and morbidity and mortality prognostic factors in ischemic heart disease. This protocol describes the technique for assessment of hydration status through bioelectrical impedance vector analysis and cardiopulmonary response during exercise stress test.

Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test

This protocol presents a method to assess pulmonary alveolar-capillary reserve measured by combined single-breath measurement of the diffusing capacity to carbon monoxide (DL,CO) and nitric oxide (DL,NO) during exercise. Assumptions and recommendations for using the technique during exercise form the foundation of this article.

Dual Test Gas Pulmonary Diffusing Capacity Measurement During Exercise in Humans Using the Single-Breath Method

This protocol integrates near-infrared spectroscopy (NIRS) technology to assess localized hematological and oxygenation changes at the prefrontal cortex, respiratory (m.Intercostales), and locomotor (m.Vastus Lateralis) muscles during cardiopulmonary exercise testing, enabling the identification of central and peripheral limiting factors affecting exercise performance.

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise

Learn how to determine energy system contributions during exercise using portable gas analyzers and mathematical modeling. This computational method quantifies aerobic, lactic, and anaerobic metabolism in unpredictable sports like judo.

Determining the Contribution of the Energy Systems During Exercise

Explore More Videos