Exercise Performance - Science topic

Where is the "crossover"?

You should consider the correlation of measrements between phases of the same patient.

Have you thought about a resonable distributionmodelfor the heart rates? I would think that a Gamma model would possibly be more appropriate than a normal model.

You might think if it makes sense just to analyze the integral of the heart rates as a measure for the total blood low.

There are surely many more things to think about. I strongly suggest meeting with a local statistician (possible via web-conference if you cannot meet personally) and discuss your project.

The Venous testing is more appropriate

Thank you, Henry Wolfe for the excellent references. So many ways to improve performance and recovery inexpensively. Too many products developed for the bottom line, not necessarily the the elite athlete or the regular exercise Joe.

We need more details, but probably the Two-way ANOVA with repeated measures is suitable...

Dear Seyyed,

Maybe the following papers will help you:

Qian S, Li M, Li G, Liu K, Li B, Jiang Q, Li L, Yang Z, Sun G. Environmental heat stress enhances mental fatigue during sustained attention task performing: evidence from an ASL perfusion study. Behav Brain Res 2015;280:6-15. https://www.sciencedirect.com/science/article/pii/S0166432814007724?via%3Dihub

Otani H, Kaya M, Tamaki A, Watson P. Separate and combined effects of exposure to heat stress and mental fatigue on endurance exercise capacity in the heat. Eur J Appl Physiol 2017;117(1):119-129. https://link.springer.com/article/10.1007%2Fs00421-016-3504-x

Robertson CV, Marino FE. Cerebral responses to exercise and the influence of heat stress in human fatigue. J Therm Biol 2017;63:10-15. https://www.sciencedirect.com/science/article/pii/S0306456516301668?via%3Dihub

Best wishes from Germany,

Martin

After consumption of CHO, there is an increased uptake of the ingested glucose into the active muscle. If insulin concentration also increases there is a reduction of lipolysis and as a result of these two actions fat oxidation is decreased. This suppression of fat oxidation following CHO ingestion can last for several hours .Consequently, an individual consuming CHO before and/or during exercise will likely oxidize less fat and more CHO during and after the exercise session

1. Horowitz JF, Mora-Rodriguez R, Byerley LO and Coyle EF. Lipolytic suppression following carbohydrate ingestion limits fat oxidation during exercise. Am J Physiol Endocrinol Metab 273: E768-E775, 1997. 22.

2. Howley ET, Bassett DR and Welch HG. Criteria for maximal oxygen uptake: review and commentary. Med Sci Sports Exerc 27: 1292-1301, 1995.

Dear Luís ,

Maybe the following paper will help you:

Ruiz-Barquín R, de la Vega Marcos R, García Carrión I. Spanish adaptation of "Psychological Characteristics of Developing Excellence Questionnaire" (PCDEQ). May 2014. Conference: XIV Congreso Nacional y I Internacional de Psicología de la Actividad Física y el Deporte., At Complejo Cultural San Francisco, Cáceres., Volume: ISBN: 978-84-7723-612-2. https://www.researchgate.net/publication/262493092_Spanish_adaptation_of_Psychological_Characteristics_of_Developing_Excellence_Questionnaire_PCDEQ

Best wishes from Germany,

Martin

How can you improove your top speed? What is the most efficient method to be faster?

Complex  

Hability tests must be associated with endurance tests

The recovery between sets should be longer than between repetitions. A set of repetitions are to targetted to be at a certain intensity. There will be times when that intensity can not be maintained unless the recovery between the sets in allowed.

Which Parameters are reduced? Amplitude, time (contraction), Area under curve...Specify your data (if it is yours), so one can get a better understanding 

Para el crossFit en mi concepto resulta interesante revisar la planificación ondulatoria que propone Kramer y la metodología por carácter del esfuerzo, donde se podría mejorar la velocidad de las ejecuciones en el entrenamiento en aras de transferir desde tal forma de entrenar una mayor velocidad de ejecución que apunte a la eficiencia en la competencia

Several validation studies can be found here https://www.fitabase.com/research-library/

Good luck!

Dear Rouven,

assessing the MIVC during bench-press, you could simply fix the bar at a certain height (probably to the subjects optimum) and put the bench itself on the force plate. Be sure the subject and the bench are completely on the force plate (if not you need an addtional construction). If the subjects now performs an isometric bench, you will get this force in addition to the gravitational force of his body weight. The similar procedure could be done for the barbell squat, however you should again fix the bar. The best heigth for the bar is dependent on your research question.

Pleas consider: 1RM is not a force measurement, so this should not be an alternative anyway.

Vorontsov A.R. (2010) Strength and power training in swimming. In: Seifert L., Cholett D. & Mujika I. (eds.) World Book of Swimming: From science to performance. Chapter 16. Nova Science Publishers.

Vorontsov A., Popov O., Binevsky D., Dyrko V. (2006) The assessment of specific strength in well-trained athletes during tethered swimming in the swimming flume. In “Biomechanics and Medicine in Swimming X”. Proceedings of the X International Symposium on Biomechanics and Medicine in Swimming, 21-24 June 2006, Porto, Portugal, pp. 275-277.

You are looking for a RPE scale pre-exercise?

It is so interesting! I dont find nothing about.

A quite comprehensive summary of factors influencing muscle strength by Jonathan Folland: http://link.springer.com/article/10.2165/00007256-200737020-00004

Hi Bryan,

We now use FirstBeat for our Team stuff. They have been excellent (much better than Polar). May be worth checking out their website for individual monitoring solutions.

 Hi Anne, I work for Polar. Maybe I can help you.

I have been measuring lactate for 20 years and have used the YSI (1500 and 2300 models) which has been the gold standard. Dr. Lange and Diaglobal are great small photometers but time consuming. In the past 5 years I have moved to Lactate Plus and Lactate Pro. Have run many comparisons with YSI and photometers and both Lactate Plus and Lactate Pro are very reliable (r=0.99). They give you results in 12 seconds which is really fast. 

I recommend you look at publications by Alison McConnell, 

and check out her blog, see links below.

dear Mukesh Soni 

i hope next site help you

Hi, Christian. In addition to what has been mentioned above, the following articles may be of assistance. Of particular interest is a recent systematic review which demonstrated that keeping it simple is best in terms of monitoring athletes' subjective reports in regards to loading/training response. 

I've also attached a link to a recent systematic review detailing the changes in different heart rate measures in response to training/loading. Hopefully these are of help!  

Hi Olga

I think cross over hop test is the best choice (depending on our experiences).

regard

First of all, epileptics fail fitness for diving in most cases including freediving or apnea diving. Only when for long time free of seizures without anticonvulsants, normal EEG and without cerebral MRT-lesions, fitness for diving can be achieved.

Secondly, regardless of CO2-content, apnea/breathhold diving can lead to hypoxia what can be followed by sudden acute symptomatic loss of consciousness and motor controll also known as "Samba", which is self-limited in length.

For this kind of hypoxia, two mechanisms are responsible:

a) In deep diving, returning to surface is alsways associated with reduction of environmental pressure, what is followed by a reduction of oxygen-partial pressure in the lungs, what leads to redistribution of oxygen from bloodstream to alveoli and cerebral hypoxia - ascent black out.

b) In pool diving for distance, hyperventilation is performed for postponing inspiratory reflexes. If stimulus to breathe in again comes too late, hypoxia ocurrs and leads to sudden shallow water black out.

You can use ACSM metabolic equations to calculate a predicted VO2max from any speed and grade on the treadmill.  The only problem is usually submaximal testing assumes a steady state heart rate during the exercise so pick a stage where the heart rate seemed to steady state.   It would probably be somewhere in the 3rd stage of the Bruce test if this is a healthy person.  The client should be walking at this stage.  If an athlete you could use the running equation which would be the speed and grade at the 4th stage. See the ACSM guidelines for the procedure to use these equations.  Hope this helps

This would probably relate closer though:

Fong, S. S., Lee, V. Y., & Pang, M. Y. (2011). Sensory organization of balance control in children with developmental coordination disorder. Research in developmental disabilities, 32(6), 2376-2382.

Fong, S. S., Guo, X., Liu, K. P., Ki, W. Y., Louie, L. H., Chung, R. C., & Macfarlane, D. J. (2016). Task-Specific Balance Training Improves the Sensory Organisation of Balance Control in Children with Developmental Coordination Disorder: A Randomised Controlled Trial. Scientific reports, 6.

Jelsma, D., Ferguson, G. D., Smits-Engelsman, B. C., & Geuze, R. H. (2015). Short-term motor learning of dynamic balance control in children with probable Developmental Coordination Disorder. Research in developmental disabilities, 38, 213-222.

Menz, S. M., Hatten, K., & Grant-Beuttler, M. (2013). Strength training for a child with suspected developmental coordination disorder. Pediatric Physical Therapy, 25(2), 214-223.

I hope this helps. and if you need the files, just buzz me.

Olá Ana,

It's a large question, interesting but and I think that a little complicated it. However, I will try to reply it. In any case, I recommend a book, which deal with your question: Sport Development in the United States: High Performance and Mass Participation. 

So,  I found it, however, only a little presentation. In this way, I recommend also you look mainly the research and studies which are developped in the USA Universities, I'm sure there are many centers of excellence in trainning for athletes in these Universities. Indeed, independently of sports modality. They apply a model of trainning that we know it's efficient, and many other countries apply successfully it .  

I hope this helps.

Sinecerely yours.

The water needs are important and often overlooked, of about 3.5 liters per day 1.75 liter of beverage, the remainder being included in the diet.

However, sweat losses may be higher (the above 4 in a few hours) in hot environments. During the year, the water intake should be supplemented with minerals to avoid hemodilution, especially during long-term exercise

In team sports (during the half-time) or in individual sports (in the rest) contributed approximately 200 ml of water containing 20 g of glucose, 1 g of sodium chloride and 1 g potassium gluconate seems desirable.

The 5-7 repetition option will provide the most accurate representation of maximal voluntary strength/1RM. The greater the number of repetitions used, the more factors are involved in order to sustain adequate force production to lift a given load. A study by Reynolds, Gordon & Robergs (2006) found 5RM testing to be significantly more accurate when predicting 1RM strength when compared to 10 and 20RM testing groups.

Prediction of one repetition maximum strength from multiple repetition maximum testing and anthropometry - This should help.

I am a contracted clinical instructor for Biodex. Training or testing using eccentric muscle actions is frequently referred to in the literature. Yet there are rules for eccentric muscle actions. Most of the studies have used isokinetic dynamometers, like the Biodex, or devices fabricated by the research team. While it is known that in studies of in vitro muscle preparations force increases above maximal isometric levels, exact velocities of movement in in vivo studies of eccentric muscle actions are an unknown quantity, therefore most have used relatively low velocities of movement. With the Biodex under passive and eccentric conditions the selection of velocities above 60 deg/sec results in a prompt asking if you really want to use the “HIGH” velocity you have selected.

We have used the S-4 to good effect in training and testing a number of joint systems and movements with eccentric muscle actions. If you go to my profile page on Research Gate you will find an abstract of a Case Study presented at ACSM’s Annual Meeting in San Diego in May, 2015. (Harding FV, R Ghatan, C Chaney, KW Mengel, J Chen, J Loyo. Clinical Case Study: Shoulder Injury – Senior Tennis. Med Sci Sports Exerc. 47(5S): S16, S17, 2015. Harding FV, R Ghatan, C Chaney, KW Mengel, J Chen, J Loyo (2015). Clinical Case Study: Shoulder Injury – Senior Tennis. American College of Sports Medicine 62nd Annual Meeting, San Diego, CA, May.)

When testing or training using the S-4, the best results will be achieved in Passive Mode. The Eccentric Mode is called Reactive Eccentric. The problem with the Reactive Eccentric Mode is the requirement for the subject to produce a percentage of the Torque causing the eccentric muscle action to trigger the dynamometer to begin the “eccentric” movement. Since a true eccentric muscle action occurs when a muscle is attempting to shorten against an overwhelming force that actually causes the muscle to be forcibly lengthened, this is not always the case in Reactive Eccentric Mode, in fact, the torque produced is generally less than a maximal isometric torque. In the Reactive Eccentric Mode, the limiting torque in the direction of movement is either too great for the subject to successfully initiate the movement, or too small to allow for the dynamometer to overcome the muscle torque created by the subject, causing the device to stop.

The answer to the problem is to use the Passive Mode. In Passive Mode, you have the ability to set the velocity of movement (as previously stated velocities of 60 deg/sec or higher cause a warning prompt to appear), and the maximum torque that must be overcome to stop the device. Velocities of 30 to 60 deg/sec are what have usually been reported in the literature; we have found that persons may have a problem developing torque initially with speeds above 60 deg/sec. However, after exposure to the exercise most can utilize velocities above 120 deg/sec. The problem with high velocities with movements having small ranges of motion is that the person becomes confused about which way they are supposed to be exerting effort. In the passive mode, the machine will move through the full range of motion set by the investigator, at the pre-set velocity, and the subject must attempt to “STOP THE MACHINE”. If you have set the Torque limit high enough to attain a true Eccentric Muscle action for the entire movement they will not be able to stop the machine and it will move at the pre-selected velocity for the desired number of repetitions.

When using subjects who have learned to use the device with eccentric muscle actions we have observed the requisite increase in torque producing capabilities across the range of 10 – 120 deg/sec. Some people experience the loss of torque producing capabilities at lower velocities, some at velocities in excess of 120 deg/sec. We hypothesized, and it has been substantiated by experience, that the loss of torque producing ability at higher velocities is a sign we have reached the physiological limit of eccentric muscle actions observed in the force – velocity curve for that individual, or it is a function of a combination of innate athletic ability and learning.

When setting up the S-4 for eccentric testing or training, go to the protocol screen. Select Add and name your protocol. Select Test or Exercise (the test set up screen for ROM has the gravity correction factor at the bottom of the screen below the calibrate position button, exercise does not). Select Bilateral or Unilateral. Select Passive Mode, the joint system, and movement to be trained or tested. With shoulder IR/ER you have two choices – Modified Neutral and 90/90. Modified Neutral is the “safest,” 90/90 is most appropriate for individuals involved in throwing and over-head/over-hand striking activities. For purposes of stabilization it is best to use a seated position, though a standing position can be utilized. Select the number of sets and set the different velocities for each set and direction of movement, THEN SET the TORQUE, we use at least 250 ft-lbs (340 Nm) for IR/ER to insure no one can stop the machine. When setting contraction type use CON/CON, any use of ECC whether CON/ECC, ECC/ECC, or ECC/CON will result in the use of the Reactive Eccentric Mode of operation.

Normative data for IR/ER is available on-line at Biodex, is in the database manager on the computer with the S-4, and in the manual. The velocities reported for IR/ER suggest they are for concentric isokinetic tests. You will be developing the normative data for you study population since to my knowledge, no normative data exists for eccentric movements. If you have further questions I am here on Research Gate.    

In Karvonen Formula you will get the target heart rate depending on the heart rate reserve. From the heart rate reserve you can determine, for instance 60% which is moderate or 80% which is sever exercise, then add to the resting heart rate which will provide target heart rate. For example a subjects resting heart rate let us take 100 and his age is 20 and we want him to moderately exercise for 20 minutes. Then his maximum heart rate is 220 minus 20 is 200. Now to find his heart rate reserve 200 minus 100 which will give us 100 which is heart rate reserve and 60% of the hear rate reserve (since we want the subject to exercise at moderate intensity) would be 60 bpm. Adding this with the resting heart rate (100 plus 60) will give the target heart rate 160 which the subject has to exercise for 20 minutes which is our aim. Heart rate is directly proportion to the intensity of the exercise.    

I did some (still) unpublished research on VO₂ uptake kinetics (i.e. mean response time - MRT) on runs above CS (i.e. severe intensity exercise domain). Participants performed three runs of different speeds (all in the severe exercise Domain) interspersed by 30 min passive rest. We found apparently faster MRTs with ongoing testing. As faster MRTs have a positive influence on the O₂-deficit, it is believed that faster MRTs improve performance.

Allometric scaling provides a method for examining the structural and functional consequences of changes in size and scale among organisms.

Dear Pawel Posluszny.

Several of our colleagues have suggested interesting solutions to solve your problem. Therefore, any additional information would be repeating what has already been said so I send you two references, one for appendicular mass calculation of old and the other for general use.

Martin, A.D.; Spenst, L.F.; Drinkwater, D.T.; Clary, J.P. Anthropometic estimation of muscle mass. Med Sci Sports Exerc. 1990; 22:729-33.

Piettra Moura Pereira Galvão, Danny Alcantara da Silva, Gilberto Moreira Santos, Luiz andAmandio Petroski Edition Aristides Rihan Gallagher. Development and validation of anthropometric equations to estimate appendicular muscle mass in elderly women. Nutrition Journal. 2013; http: www.nutritionj.comcontentpdf1475-2891-12-92.pdf

Additionally, I suggest reading the chapter: Estimation of Muscle Mass.In: Human Body Composition. Roche, A.F.; Heynsfield, S.B.; Lohman, T.G.

Good luck

 Amandio Geraldes

You mentioned measuring temperatures at several time points. Exactly how many is several? Because each measure is another DV (t1, t2,....t10 = 10 levels of the DV) and another cell you'll need an adequate n for In your statistical design to meet assumptions.

Hope some of this can help. Especially work of Mr.Ertan.

You can also look for unpublished doctoral thesis "The analysis of shooting dynamics in archery" by Tinazci C.  and  "Total Archery" book (Samick Sports) by Lee K. and Bondt R. 

I hope You will find some of this information helpful.

Kind regards,

Jan Homolak

Although Elevation Mask Training simply can not produce the effect of "elevation training" because it just makes it hard to breathe without the change in partial pressure of oxygen this or similar Masks ( eg. gas mask) and other equipment that put greater load on accessory muscles of respiration may be very beneficial in athletic training.

First of all, the importance of oxygen delivery and all of its components are often overlooked as factor for maximal perforrmance because a lot of sport physiology textbooks highlight the importance of cardiac output and lessen the importance of respiration providing wrong background for understanding of performance limitations.

Although heart (and not lungs) is a limiting factor in maximal performance it is usually overlooked potential time body can function on that level. Maximal "use" of the lungs have greater capacity than heart but it can only last for short period of time because a lot of power comes from accessory inspiratory muscles. (eg. swimming - EMG shows 100% serratus anterior activation during 100m race ) When the accessory muscles become "tired" maximal breathing capacity is drastically lowered and delivery of oxygen to blood, not heart output can become limiting factor.

All this can therefore outline the importance of accesory muscle training such as the one you mentioned with "Elevation training mask". There are of course other types of training (eg. Power Lung, Power Breathe, .. )

Some literature:

Also some on potenial pulmonary limit of exercise performance:

All in all, I believe benefit exists  but not altitude training kind of benefit.

Best regards,

Jan Homolak 

Thompson, W.R., Gordon, N.F. & Pescatello, L.S., eds., 2010. American College of Sports Medicine (ACSM s Guidelines for Exercise Testing and Prescription. 8th ed. China: Wolters Kluwer, Lippincott Williams & Wilkins.

This can be a very good support for your study, I used it for my research while at Teesside

This may not answer your question, but meaningful effect often isn't about this or that statistical calculation ... and as pointed out, adjusting absolute change by some measure of group variability can be spurious if the group you are investigating is unusually homogeneous (though "meaningful difference" is often different for different populations - a change of X points in an individual or group that is in the middle of the distribution may be more/less meaningful than the same size change for an individual/group that is towards the extreme of the distribution). A change of X on the Beck Depression Inventory may mean little in mentally healthy individuals, but be critical in patients with high levels of depression, for example. I recommend the paper by Andersen on "What do the numbers really tell us?" (Journal of Sport & Exercise Psychology, 2007, 29, 664-672) that address the whole issue of interpreting "meaningful" in the context of ordinal questionnaire data.

Continuous exercise for one hour could range in exercise intensity from as low as 10% to as high as 80% of maximal VO₂. The intensity that you choose depends on your research question. The intensity you choose would also be affected by the training status of your subjects as well as whether they are heat acclimated or not. Rehydration, as you might expect, would be more important at higher intensities than at lower intensities. For rehydration guidelines, I refer you to the reviews below.

Hi Alan, I read this today (sorry).

I´m in the middle of my research right now!!! I will collaborate with some studies. It would be awesome!!!

Thanks,

Santi

Hi Pattarawut,

The potential for 'live low - train high', so called intermittent hypoxic training (IHT), to increase high-intensity, anaerobic performance has recently been highlighted in an excellent review by McLean et al. (Sports Med 2014).

There is evidence in literature to indicate that IHT enhances glycolytic enzymes, glucose transport and pH-handling (Vogt et al., JAP 2001; Zoll et al., JAP 2006, Faiss et al., PLoS ONE 2013; Puype et al., MSSE 2013). 

The major mechanisms involved are thought to be HIF-1 activation and greater glycolytic energy turnover during IHT.

Only few studies also evaluated high-intensity or anaerobic performance following IHT. Yet, there is some evidence to support that IHT induces greater improvements in anaerobic power, RSA and YO-YO Intemittent Recovery Test performance than the same training at sea-level (Hendriksen et al., EJAP 2003; Hamlin et al., SJMSS 2010; Faiss et al., PLoS ONE 2013; Galvin et al., BJSM 2013).

Cheers,

Stefan

Thers plenty on the measurement on illegal bowling actions, and retests etc.

Rene Ferdinads work is useful in that area.  As for empiricially supported protocols for correction, I've yet to find any - but now I will search also!

Before the propulsive phase, the angles of the ankle, knee and hip are at maximum flexion in the cycle, ie ~ 70 ° of dorsiflexion to the ankle (0 ° = foot fully extended) ~ 120 ° of flexion in the knee (0 ° = fully extended) and ~ 40 ° of flexion in the hip (Janshen et al. 2009). The angular amplitudes for the knees, ankles and hips during the propulsive phase are approximately of 110 °, 70 ° and 100 ° (Janshen et al. 2009). The extension of the legs is more or less complete depending on the level of the rowers (Hase et al. 2004). See also Soper and Hume 2004 and  Rodriguez et al. 1990.

Hi Richard,

You may wish to look at Feltz and Chase's Outcome Expectancies scale here and adapt the way it is used slightly to fit your research design.

Many Thanks

John

Hi Guys.

 I would like to know if you have experience with arm-crank exercise tests in patients with vascular disease, such as Peripheral Artery Disease patients.

Thanks

Hi we have sued the Actiheart which uses a branched equation model to estimate energy expenditure. The device is quite expensive but has generates data comparable to indirect calorimetry in variety of intermittent and continuous activities 

It's a very interesting topic. You will really find a lot of knowledge about the genetic polymosphisms candidate to influence sports performance in Pubmed. However, you have to consider that, at the present days, we haven't a complete answer about the genetics influence on athletes. In a practical viewpoint, as you mentioned, is easy to observe suggestions of a genetic determination. However, the mechanisms and magnitudes that it happens remains not absolutely clear. Should you interpret the studies with caution and to stablish a logical link between genetics, environment and performance. Further, keep in mind: undoubtedly, there is a need for more clear statements before practical conclusions.

We have used the Metamax 3x gas analysis system extensively in our research studies. As the above answers suggest you need to calibrate with different gases than you would normally use. We use our normobaric hypoxic chamber at FIO₂:0.12 a great deal and subsequently we calibrate with gas mixture of 7%O₂, 5%CO₂ and 15%O₂, 3%CO₂. We have compared the validity and reproducibility of these measures to the gold standard douglas bag method with the Haldane transformation. Due to ventilatroy increases the CoV tends to be a little larger than you would expect in a normobaric normoxia.

Hope this helps

Dear Dan,

The method of determination of VO2max during submaximal treadmill test can be found also here:

Ebbeling, C.B.; Ward, A.; Puleo, E.M.; Widrick, J.; Rippe, J.M. Development of a single-stage submaximal treadmill walking test. Med Sci Sports Exerc. 1991, 23, 966-973.

regards,

Marcin

Did you see this: http://speedendurance.com/2011/12/02/do-sprinters-breathe-when-sprinting/?

You can make special video filming for researching breathing during the start.

Diaphragm pressing? ... It is difficult! :)

Dr Gareth Wallis (at Birmingham as I'm sure you know) has done work on male/female differences with CHO and fat metabolism: 

In terms of pre exercise CHO ingestion - good paper by Dr Stuart Galloway on some research we did at Stirling: 

Seems like a good place to start developing your question.  

Hi Carolien,

let me follow up from ricardo's point. A study before the one you describe may have informed you of the number of tests required for the response to settle. That your systematically find a better response on the second attempt may mean that you could get a great score on the third, possibly fourth, etc, response. I suggest you look into measures of absolute vs relative reliability in the literature (isokinetic testing is a good entry point too) to think beyond the simple test-retest procedure.

Just as I suspected, thank you for your comments, Mar. 

We tend to see 'objective' measures as a gold standard at the moment but we also need to be aware of the pitfalls in all measurement techniques. Bear in mind that if you attempt to 'validate' a self-report measure with an 'objective' measure such as accelerometry or pedometry that such validation will never be perfect as all these measures do not assess physical activity in exactly the same way, they each measure a different aspect of physical activity. So accelerometers would not be able to assess the type of physical activity or anything contextual, as a diary would, and would miss out certain forms of activity depending on the placement of the device on the body. So for example an accelerometer placed on the hip would miss any upper body motion, such as lifting weights or carrying shopping bags. Many accelerometers would have to be taken off to swim. A pedometer merely counts steps but says nothing about the frequency, intensity or duration of physical activity. Like self-report measures, these devices rely on the participant engaging with them appropriately. Also, be aware that physical activity guidelines (e.g. 5 x 30 mins per week) were developed on the basis of self-reported physical activity; guidelines based on accelerometry, when they emerge, may well require less of people. These are a few things I discovered when I undertook a rapid scoping review of literature on physical activity measurement in the spring of this year - please let me know if you want references for these points.

I've the book and is an excellent work, actually you can found two excellent papers from Martin Buccheit: HIT, Solutions to the Programming Puzzle (part 1, and part 2). Regrads

Look at the works of:

Carroll TJ (e.g. Contralateral effects of unilateral strength training... J Appl Physiol 101(5):1514-1522, 2006)

Farthing J (e.g. Strength training the free limb attenuates strength loss during unilateral immobilization... J Appl Physiol 106(3):830-6, 2009)

We examined this in the study I've linked below. At the time we examined global field power but we might have seen differences if we had analyzed for a different outcome variable. This is something I may follow up on this in the future.

We have had successful rests in measuring core body temperature via heat flux double sensor.

It's seen use on board the international space station, Antarctic winter crews, as well as the operating room. Also, it has been recently field tested during centrifuge runs. The data is promising.

Mohd, the basic devices could be:

- Motorized Treadmill;

- Cycle ergometer (mechanical Monark or an eletromagnetic with accurate load adjustments);

- Cardiorespiratory acquirement system (Pulmonary Gas analyser);

- Blood lactate analyser (Yellow Spring are very accurate);

- Equipments to blood sample (tubes, capillary, solutions etc);

I think this is the basic to use both in teaching and researching. The difference between both are in quantity of ergometers and metabolic devices. For teach purpose you will need more than one.

Hope to help.

Dear Béres

Take a look at this link. If you cannot open the full text just contact me

Dear Kao

Maybe these papers will help you

1) Running speed and maximal oxygen uptake in rats and mice: practical implications for exercise training.

Høydal MA, Wisløff U, Kemi OJ, Ellingsen O.

Eur J Cardiovasc Prev Rehabil. 2007 Dec;14(6):753-60.

2) Downhill treadmill running trains the rat spinotrapezius muscle.

Hahn SA, Ferreira LF, Williams JB, Jansson KP, Behnke BJ, Musch TI, Poole DC.

J Appl Physiol (1985). 2007 Jan;102(1):412-6.

Dear Paolo,

I have been training for almost 30 years as an athlete (long jump, 400m hurdle, 60m, 100m, 200m, 400m and decathlon). I have never been in world class just in national upper class. (100m - 10.61s, 200m - 21.70s, long jump 7.60m). My experience is – to run a short distance (from 30m - to 200m) from standing start always bring better result than from block start (independent start – no sound, clap or starter gun, stopper stared for the movement of the leg). Always! There is something strange in it, because this is not logical from biomechanical point of view. This one is tell us that the block start is a very complicated, massive technical question. For example the question of the swinging arms (the question of the arm swinging backward), and/or the question of the role of the head (6kg part CG) raising etc.

But. To start to a sound sign is much more different. The blocks counteract the energy loss (backward movement) if the block angles, hip highness, knee angles, CG positioning are adjusted correctly. While the runner starting from block (to a sound sign) push her/himself forward, the runner starting from standing position will not help any “equipment” to support the heel (it true that you don’t need to raise your CG and there is no such weight on quadriceps).

So. Is the standing or block start a more effective at track and field sprint events, from a point of view of performance and biomechanically? It depend on the starting procedure (to a sound sign – like in race circumstances, or to independently – like in training circumstances) or it depend on technical, power, experience level of the sprinter or …? I think this is not so obvious.

Thank you for your answers. I want to compare persons with different body composition and/or overweight vs. normal.

I agree with Carles. The FIFA 11+ is well established and there is enough evidence that it works on levels below professionals. However, as there is no other program that has been studied in professionals and there is no research that it will not work on pros, I wonder why the value of such a program for highest level athetes is that heavily negated.

I agree that there is a trend in professionals (also in the highest youth and women´s leagues) to individualization (regarding fitness, recovery, injury prevention). But programs like the 11+ can serve as an evidence-based blue-print for the highest level, too. At least, as long as no other research is available (and that means that people who are active on the highest level must allow, support and initialize research in these athletes).

I would recommend use of a hand-held dynamometer, that is a dynamometer held by the examiner and applied against the patient. Hand-held dynamometers are portable and lightweight. More than 500 articles have been published that report their use. I have used them to measure the strength of the shoulder flexors, extensors, abductors, medial rotators and lateral rotators, elbow flexors and extensors, forearm pronators and supinators, and wrist extensors. Normative values are available for some of the aforementioned muscle actions.

Kim, look at the work by Brian Whipp, Sue Ward and more lately Harry Rossiter (UCLA) they spent a large amount of effort in refining the measurement and analysis of gas kinetics.

She also offers a webinar via Human Kinetics that you can get for free

Though no expert on statistics, I think there are two populations that could be studied. First is, among all juniors (high school aged kids in the US) who join a sports team, how many will become elites. It starts with a very large group and is narrowed down to a very small group over the time course of 7-10 years. In my example above, it was 7 years (meeting the definition of a gold medal at U23 World Championships as putting an athlete into the elite status). The second population to be studied is among a group of elites, how did those elites get to that status. That's a much smaller group to study..

My athletes are in the first group- hundreds of kids who became high school rowers, two of whom went on to elite status (gold medals at U23 world championships). Along the way, some of my very gifted athletes left the ranks of rowing. The reasons are many, often related to money and college.

One study is not the inverse of the other. They are very different populations.

I scan the literature and search for articles but haven't found much that offers insight into the first group. A detailed look at the second group is in the book "Developing Talent in Young People" by Dr. Benjamin Bloom in which his group studied 120 very talented "elites" and detailed how they group achieved that status. It is available on Amazon.

Dear Srinivasa,

Medial tibial stress syndrome is associated with an imbalance of foot pressure (greater on the medial foot), excessive pronation, sudden increase in intensity and/or duration of training, and an uneven training terrain. These factors increase soleus strain by eccentric contraction to resist pronation. In a separate study, decreased hip internal rotation, increased ankle plantar flexion, and positive navicular drop were associated with medial tibial stress syndrome.(References:. Pell RFt, Khanuja HS, Cooley GR. Leg pain in the running athlete. J Am Acad Orthop Surg. 2004;12:396-404. [PubMed]. Sharma J, Golby J, Greeves J, Spears IR. Biomechanical and lifestyle risk factors for medial tibia stress syndrome in army recruits: a prospective study. Gait Posture. 2011;33:361-365. [PubMed]. . Moen MH, Bongers T, Bakker EW, et al. Risk factors and prognostic indicators for medial tibial stress syndrome. Scand J Med Sci Sports. 2012;22:34-39. [PubMed].)

Treatment strategies for medial tibial stress syndrome frequently include rest and cross-training using low-impact activities such as stationary biking and underwater running. Once symptoms resolve, training should slowly accelerate (10% to 25% every 3 to 6 weeks). (REFERENCES :. Kortebein PM, Kaufman KR, Basford JR, Stuart MJ. Medial tibial stress syndrome. Med Sci Sports Exerc. 2000;32:S27-S33. [PubMed]. Edwards PH, Jr, Wright ML, Hartman JF. A practical approach for the differential diagnosis of chronic leg pain in the athlete. Am J Sports Med. 2005;33:1241-1249. )The most effective surgical procedures involve release of the deep posterior compartment, including the soleus sling and removal of a strip of posteromedial tibia periosteum (REFERENCES : Detmer DE. Chronic shin splints: classification and management of medial tibial stress syndrome. Sports Med. 1986;3:436-446. [PubMed] .Yates B, Allen MJ, Barnes MR. Outcome of surgical treatment of medial tibial stress syndrome. J Bone Joint Surg Am. 2003;85:1974-1980.) Also surgeon must adress the etiology of the disease if any malalignment (imbalance of foot pressure (greater on the medial foot), excessive pronation,decreased hip internal rotation, increased ankle plantar flexion, and positive navicular drop ) detected .surgeon must focus on to solve these pronblems first.

Yours respectfully

It depends on what you see as your outcome variable. If you plan to estimate VO2max, bear in mind that many equations or conversion tables incorporate body mass, and if the intervention program is successful at reducing body mass, changes in estimated VO2max may result from the role of body mass in calculating the VO2max estimate. For obese children, "functional fitness" may be a more reasonable outcome - so whatever standardised test you use, it may be more appropriate to use the raw performance score (time to completion, distance covered, laps completed). Also consider safety issues with maximal effort tests (such as the 20-m shuttle). Risk screening and ethics screening in many countries make maximal testing either a lot of bother, or not possible (because participants are screened out of maximal performance tests). For that reason, a walk test or submaximal cycle test maybe more practical and safer. From previous work with obese children, they tend to like cycle exercise and cycle testing (because it is less impact on joints, and they tend to be quite good at cycling). A cycle test is also less weigh-dependent (so you would obtain a purer measure of improvement in fitness, rather than reduction in body mass). Sounds like you want something more straightforward, equipment-wise, so this may not be feasible. If you use the 20-m shuttle, consider using the raw performance score (laps) as suggested. If you really want to estimate VO2max, maybe search for a lap-dependent equation, rather than use the Leger equation (which I think uses stages completed, rather than laps).

What kind of transition are we talking about here? A transition from one team to another? Or a transition from junior level to senior level? Etc. That probably makes quite some difference with regard to the interventions that could be put in place. I am not sure whether this concept would be completely applicable to professional football players, but you may want to look at the concept of career adaptability. Jessie Koen has published about an intervention with regard to career adaptability of young individuals with regard to the school-to-work transition. Not sure whether this helps in your particular case, but maybe you could look into it. I have also developed an intevention myself which is aimed at developing career competencies of young workers. This is mainly about reflective, communicative and behavior career competencies. Again though, I am not sure whether this can be applied to your specific context.

Dear Philip,

You should check the last special issue of British Journal of Sports Medicine focusing on altitude training for team sports.

In addition to undeniable team building effects, the small physiological benefits may help to make the difference on the field (winning depends on details). For that, new methods such as repeated sprinting in hypoxia may be very promising... see the last papers from our research group but also the one of Galvin or Puype.

However, more studies are still needed to confirm possible anaerobic/neuromuscular benefits from team sports' hypoxic training.

Regards,

Franck

Dear Mohsen,

An interesting debate. I would consider this exercise an open kinetic chain exercise as the distal segment (although attached to a platform – which is moving) is moving around/away from the proximal segment. A squat or push up for example has the proximal segment moving around the distal segment. In saying this there are also kinetic link or pseudo-chain movements that have both occurring at the same time - a push press exercise for example has the lower body performing a closed kinetic chain exercise while the upperbody is performing an open kinetic chain exercise. I would urge against trying to tie in joint compression into the mechanical term as this can be misleading. Consider a chin up...this exercise has a joint distraction but is closed kinetic chain as the proximal segment is moving around the distal segment. Likewise zero gravity conditioning (like that required for astronauts) adds a new dimension.

Just to mix it up a little further, the concept of kinetic chains is an engineering one that is attributed to a mechanical engineer named Franz Reuleaux (circa 1875) who describes a series of overlapping segments connected via pin joints. These interlocking joints would create a system that would allow the movement of one joint to affect the movement of another joint within the kinetic link (hence the term of a kinetic link exercises which has two compound movements joined together – push press, baseball pitch, etc)

Regards

Rob

Dempster works surprisingly well for a wide range of body types. More accurate estimates have attempted to define certain body types, but even with DEXA and a three component mass model (fat, muscle, bone) the estimates have not been much better. Dempster did a HUGE amount of work, and his report is 20MB