Physiological Demands Of The Marathon

Physiological Demands Of The Marathon excoriation Speedie is a national take drive runner, aged 25. Historic eachy his prep has involved invariable campaigncourse cultivation but he understands that interval facts of life and/or subway cooking whitethorn and enhance his sufficeance.The aim of the battle of Marathon is to maintain a luxuriously precedent output everyplace the official 42.195km aloofness, a exploit which requires substantial physical and psychological prep bedness (John A. Hawley Fiona J. Spargo, 2007 McLaughlin, Howley, Bas hatfult, Thompson, Fitzhugh, 2010). Success in the g all overnment issue depends upon a number of physiologic, psychological and environmental factors. National level marathon speed demands a high oxidative capacity and the ability to perform at a high fraction of it for a sustained period of time of time. A complex interplay of cardiovascular, musculoskeletal, pulmonary, and metabolous systems is necessary to achieve this. The purpose of this compendious is to outline the physiological demands of the marathon, the mechanisms of writ of execution resultant of the aforementi peerlessd characteristics and to introduce reproduction methods documented in recent literature to enhance attributes and proceeding (time) of the marathon at national level.A.V Hill (1926) embraces a high VO2Max to be the depict determinant underpinning courage writ of execution. Astrand and Rodahl (1986) describe VO2Max as the highest localise at which the organic structure thr genius uptake and utilise oxygen (O2) during severe exercise at sea level it sets the ceiling of adenosine triphosphate production through with(predicate) oxidative phosphorylation and is a key determinant of marathon public presentation. VO2max is traditionally increase as a result of performing high sight, low chroma (60% VO2Max) prospicient slow distance (LSD) travel rapidly.The ac wager book of oxygen consumed (VO2) (Berger, Campbell, Wilkerson, J integritys) at a precondition exploit rate, is to a greater extent commonly termed running economy (RE) or set forth as the metabolic cost of running (Cr). McLaughlin et al., (2010) report a industrial-strength correlation amidst RE and 16km time (r =0.812), Billet et al. (2001) suggest a strong correlation between VO2Peak and Cr (r=0.65, P= 0.04), and Midgley et al. (2006) detail exceedingly correlated (r=0.62) mitigatements in RE with LSD rearing (Midgley, McNaughton, Wilkinson, 2006 McLaughlin, et al., 2010), similarly justification cookery has been describe to derive similar emendments in RE ( Bonacci, Chapman, Blanch, Vicenzino, 2009 Storen, Helgerud, Stoa, Hoff, 2008a). question on lactate threshold (LT) suggest it is a sound forecaster of marathon race pep pill (Coyle, 2007). Once considered largely a down product of glycolysis lactate (La-) is now considered an chief(prenominal) metabolic fuel (Gladden, 2004). La- increases argon indicative of work rates exceeding possible levels of fat oxidisation required to sustain adenosine triphosphate production, therefore intracellular signalling stimulates glycogenolysis and glycolysis to meet ATP demands (Joyner Coyle, 2008 Spriet, 2007).The efficacy of alternative procreation communications protocols said to enhance physiological traits of marathon performance are emerging. Improvements of up to 7% in RE are been reported following resistance training protocols (Berryman, Maurel, Bosquet, 2010 Paavolainen, Hakkinen, Hamalainen, Nummela, Rusko, 1999 Saunders, et al., 2006 Spurrs, Murphy, Watsford, 2003), primarily cod to topping stretch shortening cycle (SSC) function in consequence of c menstruatee magnitude musculotendinous stiffness (A. N. M. C. food turner Jeffreys, 2010). Similarly, tantalize is purported to repair survival of the fittest performance through possible mechanisms including ponderousness La- buffering capacity (Laursen, 2010), enhanced enzymat ic functioning, skeletal muscleman remodelling (Burgomaster, et al., 2008) and metabolic adaptations such as mitochondrial biogenesis (Hawley, et al., 2007). Moreover hypothesis adjoin muscle fibre type transitions and hybrid myosin isoforms, suggest place and high forte interval training (HIIT) whitethorn elicit structural changes resulting in a greater oxidative capacity of muscle and improved endurance performance (Kubukeli, Noakes, Dennis, 2002).The following article will discuss these mechanisms in further and include recommendations of various training protocols, reported to improve performance..Word consider 574Athlete Profile Mark SpeedieNational athlete, Mark Speedie, has traditionally employ sustained training protocols for race preparation, 71% of total training volume comprising of low intensity training (Table 1. Athlete Profile Mark Speedie, sub- selected marathon runnerNZ Ranking4thCurrent career goals2016 Olympic podium contenderAge (years)25W eight-spot ( kg)60 heyday (cm)172PRM (hrminss)22200vMarathon (km.hr-1)17.8VO2Peak (mL.kg-1.min-1)70LT (%VO2Peak) unfathomedCr (mL.kg-1.km-1)UnknownMHR (BPM)195Cr = Metabolic cost of running (aka running economy), LT = Lactate Threshold, MHR = maximal heart rate, PRM = personal record for the marathon, vMarathon = velocity for marathon distanceIn addition to the efficient, integrated nature of automobile trunk systems required to prove elite performance, body mass and composition, as described by Pollock et.al.,(1977) reported elite marathoners ideally weigh between 59.6 and 66.2 kg with a body fat percentage of approximately 5 2%. A run for stature has been reported to more economical during endurance events for movement efficiency, aerobiotic economy and heat dissipation (Billat, et al., 2001 Pollock, et al., 1977).AssessmentsBefore recommending new training protocols, it is all important(predicate) to determine the current physiological status of Mark utilise enamor, binding and sur e assessment strategies.Laboratory AssessmentIntermittent or continuous salt mine protocols performed in the laboratory are used to obtain breeding pertaining to oxidative function, including VO2Max, RER and metabolic cost of exercise (Cr, RE). Intermittent treadmill protocol is widely used, and has the advantage of 30s recovery periods in which blood samples can be taken to measure substrate levels such as lactate (BLa-). A minimum 3 minute increment is recommended by ACSM (ACSM Guidelines for Exercise mental testing and Prescription, 2010, p79) increase velocity and/or inclination each increment until one of the following occurs VO2 reaches a plateau despite increasing velocity or inclination RER 1.15 (Esteve-Lanao, et al., 2005) peak HR 95% age-predicted max or RPE of 19 (ACSM p83) afterward which VO2Max is determined. Similarly, volitional exhaustion may end the test, the highest unconstipated nominate VO2 is recorded as VO2Peak. Midgley et al. (2006) report significant differences in vVO2Max (km.hr-1) following three treadmill protocols, which demonstrates the magnificence of considering the methodological variations of test protocols and training intensities based upon them when prescribing exercise intensity. It should be mentioned that several(prenominal) articles cited within this report, use the Wingate anaerobic test ( expect) to determine anaerobic and aerobic function in cyclists, as yet in a recent study, WAnT was not significantly associated with and therefore not a valid tool, for assessing aerobic function in endurance runners (Legaz-Arrese, Mungua-Izquierdo, Carranza-Garca, Torres-Dvila, 2011).BLa- is measured during intermittent treadmill test recovery stages victimization the Lactate Pro blood lactate analyser, a minimally invasive, fast, accurate and valid test (Pyne, Boston, Martin, Logan, 2000) where blood (5l) is taken from either the ear lobe or tip of the second digit after charm sterilisation of the area. It is impor tant when re-testing that the same sample point is used as the ear and finger may reflect varying measures of BLa-.Rate of sensed exertion (RPE) and heart rate (HR), as recommended by ACSM (p83) is monitored during incremental treadmill testing, a numerical scale (RPE) and heart rate monitoring guile (Polar, Finland) are used during testing, respectively. ECG is used where possible to measure HR as a more accurate and intricate measure. information intensities can then be quantified and prescribed proportional to VO2Max, RER, vVO2Max and BLa-, using HR and RPE, to improve program efficacy.Muscle PerformancePrior to recommending resistance training protocols it is necessary to obtain baseline measures so as to accurately prescribed loads, and progress. typically the leg shake is recommended to assess lower body strength (ACSM p 90 92), however given the different kinematic variables between leg press movements and running gait a 1RM squat test will be used as kinematics close r represent gait. The athlete must be familiarised with the movement test protocols must be standardized using appropriate warm up, trial numbers and progressive load increments and standardisation of squat depth, stance and bar placement are crucial. The use of a linear position transducer during the squat test provides a fast, efficient and reliable means of measuring useful information such as wring, antecedent and velocity, beneficial to program prescription medicine and efficacy (Garca-Pallars, Snchez-Medina, Carrasco, Daz, Izquierdo, 2009 Harris, Cronin, Hopkins, Hansen, 2008).The modified reactive strength index (RSI) is a reliable and valid scientific tool for measuring SSC efficiency. Recall that improvements in RE are documented to be due to an increase in SSC function. The modified RSI replaces depth take shape with the counter movement jump (CMJ), swapping stain contact time with fraudulence time to calculate SSC efficiency. CMJ involves eccentric (load), amort ization and concentric (unload) bods of the SSC mechanisms (Ebben Petushek, 2010 Flanagan, Ebben, Jensen, 2008).Additional to baseline measures, it is important to track ongoing training status to avoid probable overtraining, and to ensure appropriate training stimulus is being prescribed. explore is currently assessing the reliability and validity of heart rate variability (HRV) and heart rate recovery time (HRRT), as assessment tools, used to prognosticate the lot of the athletes next training bout or race. Manzi et a. (2009) suggest the HRV may indicate a high level of performance or exercise eagerness (Manzi, et al., 2009), suggesting HRV to be a useful tool to determine training progression. Furthermore, Buchheit et al (2009) report HRR to be a useful non-invasive means of measuring the athletes physiological status (Buchheit, et al., 2008 Manzi, et al., 2009). Further interrogation is required to assess the reliability of HRR and HRV in elite and sub-elite athletes u ndertaking a combined endurance and strength training regime however may be useful for testing circle following aerobic and anaerobic training sessions.Field TestIn addition to laboratory based testing, it is important to assess performance measures using activities which simulate race conditions. For Mark, a 10km track run is performed to determine performance time (10PT). Coyle et al. (2007) report marathon race velocity to be 10% slower when compared with 10PT and to be an appropriate test to measure physiological improvements in marathon athletes. educational activity ModelsTraining adaptations require appropriate stimulus and prescription of mode, sequence, frequency, loads and intensities, fleck balancing accompanied stress responses to elicit performance improvements. While the dose-response relationship is gaining more ground in scientific research a previously mentioned, training models and intensities are surface documented.Training Zones shed been widely used in asso ciation with data points determined during squander and blood analysis to mark training intensity. These include percentage of, or HR at, VO2Max, LT or vVO2Max. A number of associated training models are discussed in the literature with respect to endurance running, additional to traditional training methods.The Polarized Training Model, whereby athletes perform a high percentage (75%) of training volume in Zone 1(The Threshold Training Model, more commonly used with furious and moderately instruct individuals, involves the athlete performing a large member of their training in Zone 2 (60 75% VO2Max)(Esteve-Lanao et al, 2007), at or around the ventilatory threshold or maximal lactate steady state (MLSS) (Laursen, 2010). It has been documented that LT, is closely related to marathon velocity (Coyle, 2007 Roecker, S., Niess, H., Dickhuth., 1998). extend training at this higher intensity, however, is shown to down-regulate the sympathetic nervous system (SNS), subsequently, due t o a decrease in catecholamine secretion and sensitivity, reducing Q and blood distribution resulting in reduced performance (Esteve-Lanao, et al., 2007 Lehmann, et al., 1992). light upon is effective however, when prescribed over short duration, concomitant to reduced volume and monitoring. Acevedo and Goldfarb (1989) report improvements in 10PT of 3%, despite no change in VO2Max or ventilatory threshold, after HIT bouts in well- teach long-distance runners (Acevedo Goldfarb, 1989). In a study on highly practised middle and long distance runners Denadai et al., (2006) report 1.2 4.2% improvements in vVO2max, RE (2.6-6.3%) and 1500m performance (0.8-1.9%) following intravenous feeding work hebdomads HIT, twice per calendar week, performed at 95% to 100% vVO2Max for 60% of the time that subjects were able to remain at that velocity during assessment (Denadai, de Mello, Greco, Ortiz, 2006).More recently, sprint interval training (posture) performed at all out maximal efforts h as been shown to elicit similar metabolic responses in well trained endurance cyclists (Burgomaster, Heigenhauser, Gibala, 2004 Lindsay, et al., 1996 Talanian, Macklin, Peiffer, Parker, Quintana, 2003) and distance runners (Macpherson, Hazell, Olver, Paterson, Lemon, 2011 Mujika, 2010), with concomitant improvements in endurance performance, metabolic control, RE (5.7 7.6 %) (Iaia, et al., 2009) and skeletal muscle adaptations. Alterations in aerobic power and encircling(prenominal) mechanisms as documented in a study by Macpherson et.al (2011), report significant improvements in VO2Max (P = 0.001) of 11.5% (46.8 1.6 to 52.2 2.0 mL.kg.-1.min-1) and a(VO2)difference (7.1%) without changes in SV or Q, suggesting aerobic improvements after stupefy are as a result of peripheral alterations. Moreover present has been shown to induce alterations in skeletal muscle mitochondrial enzymes citrate synthase CS, 3-hydroxyacyl CoA dehydrogenase -HAD, suggestive of increase lipid oxidati on pyruvate dehydrogenase PDH, indicating decrease in skeletal muscle CHO oxidation, muscle glycogenolysis and PCr utilisation similar to that reported after endurance training (Burgomaster, et al., 2008). -HAD stimulus following SIT, is potentially the result of a rapid decrease in muscle PCr availability in conjunction with continued high work rates required to generate maximal power (Spriet, 2007). In a study by Hazell et al. (2011) authors suggest that the coupling of PCr hydrolysis and oxidative phosphorylation provide an neat challenge to the mitochondria resulting in adaptation and that insufficient recoveries between exercise bouts force skeletal muscle to regenerate ATP as anaerobic component decreases, may contribute to improved aerobic power following SIT (Hazell, MacPherson, Gravelle, Lemon, 2010).Furthermore, increases in skeletal muscle buffering capacity (m) ( 200 240 atom H+ /g dry wt/pH unit), content of MCT 1 (monocarboxylate 1), found predominantly in type I fibres and required for La- beguileation into muscle fibres for ATP production and MCT 4, found in type II fibres, required for La- transport out of muscle fibres of 70% and 30% respectively (Kubukeli, et al., 2002) has been documented relative to improved anaerobic performance (Gibala, et al., 2006) following SIT. to boot, Gibala et.al. (2009), report increases in AMP- activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK) and calcium signalling mechanisms all of which are purported to be involved in the rule of peroxisome proliferator activated receptor gamma coactivator 1 alpha (PGC-1), which coordinates mitochondrial biogenesis. The oxidative enzyme expression regulation in skeletal muscle, suggests potential skeletal muscle remodelling (Gibala, et al., 2006) following SIT. hard up muscle plasticity is inconclusive however a recent offspring by McCarthy (2011) indicates the coordination of fibre-type transitions through non-coding RNA (MiRNA) suggest coord ination of fibre-type changes in response to adapted training stimulus supporting the theory of skeletal muscle remodelling (McCarthy, 2011). enjoin suggests that various resistance training protocols can improve long distance running performance, by enhancing biomechanical structures to reduce fatigue and injury as a result of inefficient movement. Further, resistance training has been well documented to improve RE and endurance performance (Mikkola, Rusko, Nummela, Pollari, Hakkinen, 2007 Paavolainen, et al., 1999 Storen, et al., 2008a).Performance improvements are indicative of neuromuscular stretch shortening cycle (SSC) adaptations (Saunders, et al., 2006) and reportedly due to an increase in -motor neuron potentiation and subsequent increase in motor unit (MU) annoyance greater contractile force improved spooky connections at spinal anaesthesia level increase MU synchronisation, and consequent rate of force development (RFD) (Wilmore, 2008 pp206 Drinkwater et al. 2009) and alterations to neural inhibitory mechanisms decreasing co-activation of antagonist muscles (Hoff Helgerud, 2004 Millet, Jaouen, Borrani, Candau, 2002). Hoff et.al., (2004) suggest RFD increases (52.3%) in soccer players improve overall economy moreover, reported a positive correlation between arterial flow transit time and a(VO2) difference potentially increasing time to fatigue at submaximal velocities (Hoff Helgerud, 2004 Storen, Helgerud, Stoa, Hoff, 2008b). Furthermore, Turner et. al. (2010) suggest that plyometric training induces increased musculotendinous stiffness (MTS), positively correlated with improved power, force and velocity (Bosjen-Moller et. al., 2005), shorter ground contact times (Kuitunen et. al., 2002) and enhanced propulsive forces during toe off (A. M. Turner, Owings, Schwane, 2003 A. N. M. C. Turner Jeffreys, 2010) contribute to improved SSC function.Exercise Prescription RecommendationsThe progressive implementation of resistance training protocols for a marathon athlete such as Mark, is required to produce adaptations safely and effectively. He is advised to employ a 2 to three day per week model signly, graduating intensity, complexity, frequency and/or duration because as performance indicators improve and tolerance levels adjust. General, functional in force(p) body exercises (low weight, high repetition) aimed at improving muscular endurance musculoskeletal condition and motor coordination are recommended in accordance to Esteve-Lanao (2007). The athletes psychological state is important when altering training parameters, circuit training protocols which elicit a HR response, include eight to 10 exercises, followed by short running intervals (400m) may be beneficial to the athletes transition to resistance training.Following the initial conditioning phase, a heavy strength cycle of quadruplet to eight weeks, performed devil to three days per week, with low (one to five) repetitions of heavy loads as derived from streng th assessments is recommended. Improvements of approximately 5% demonstrated during foursome to 10 week interventions (Kelly et. al., 2008, Storen et.al., 2008, Millet et.al., 2002) are detailed in Table 2. Exercises should remain functional multi-joint movements (squats, deadlifts, lunges) and aim to develop neural alterations to musculature highly involved in running gait at SSC movements.volatile and eccentric training protocols, including power exercises (jump squats, hang clean), gait development (single leg squat), and eccentric load (Nordic curls) should follow in the late stages of the conditioning phase. These methods have been shown to improve RFD and muscle power factors. Research suggests one to two days of explosive training, over a four to eight week period is comely for obtaining desired power adaptations, and maintaining strength. whatever(prenominal) low volume, low intensity plyometric training may be include during this phase also (Berryman et. al., 2010, Paa volanien et.al., 1999) aimed at condition SSC mechanisms.Plyometric training (jumping, hopping, bounding and skipping) has been reported to produce improvements in RE and endurance performance of up to 7% and 4.8% respectively, in highly trained endurance runners when performed at high intensities, in as little as one to three sessions per week over a six to eight week period (Berryman et. al., 2010). High intensity plyometric training can be implemented leading up to arguing phase and is specifically designed to improve SSC function. Functional resistance run training, including running with vests, sleds, chutes, hills, sand or mud, during this phase is recommended. Estevo-Lanao (2007) suggests this should be performed at specific competition velocity and should be coordinated with a reduced running volume leading into the late competition phase.Mark is advised to continue with one maintenance strength session per week, at low load and intensity with adequate recovery intervals so as not to cause any muscle damage leading into his main races, allowing approximately one to two weeks taper, whereby no resistance training should be performed. Re-testing of performance and strength parameters preceding to commencing a new training phase is recommended to assess and make changes accordingly for the subsequent training cycles.During the base phase of training, HIT and SIT may be used supplementary to LSD training. Reports have shown that replacing 25% to 90% (Burgomaster, et al., 2008) of LSD volume with HIT/SIT has not changed performance times, however has produceed similar metabolic responses when compared to LSD. As the literature fails to report performance improvements, it is advised that these extreme volumes of LSD are not removed from attach schedule however a reduction a volume is recommended when implementing SIT. It is adequate to say that responses from HIT and SIT occur substantially and quickly, requiring no more than four to six weeks at high vol umes (J. Esteve-Lanao, et al., 2007 Gibala, et al., 2006 Hazell, et al., 2010). Typically, SIT protocols include four to six 30-s all out bouts of running, separated by two to four minutes of recovery (Burgomaster, et al., 2008 Gibala, et al., 2006). Training progression should also be apply to SIT, increasing the number of all out bouts from four to six repetitions over the recommended four to six week duration, after which, ATP is reduced significantly and no further metabolic or skeletal changes evident. With this in mind, HIT and SIT protocols should be introduced at approximately six weeks out from the prime(prenominal) main priority race in the competition phase, after appropriate re-testing signifying required adaptations (Gibala, et al., 2006).Cardiovascular, metabolic and neural alterations and also muscular improvements contribute to race performance by 2% to 8% in distance runners in a recent study by Lunden (2010). Conversely, single fibre power of MHC IIa muscle fibre s appear to be a prevalent adaptation, and likely reader to the 3% improvement in running performance reported by Luden et al. (2010) as such a taper period of one to two weeks with a load decrease of 50% in week one and a further 25% in week two, is recommended, in fix to yield the physiological alterations of training (Luden, et al., 2010).To summarise, metabolic adaptations, similar to those seen after continuous training protocols, have been reported after four to six week interventions of SIT at a substantially lower training volumes than LSD, qualification this an effective method of training to maintain metabolic condition while reducing training volume. MHC isoform transitions, resulting in more oxidative IIa fibres, although requiring further research, indicates that SIT/HIT be beneficial for enhancing neuromuscular parameters and also peripheral factors (O2 utilisation) associated with endurance performance at the elite level. Potentially, a greater population of IIa fi bres, in conjunction with metabolic alterations resulting in more efficient lipid oxidation and CHO sparing, may contribute to greater power output from higher mark fibres, with maximum metabolic efficiency, particularly in the final stages of the marathon, where lower station fibres and fuel sources are depleted. Future research is required to determine cardio-respiratory factors which may be affected as a result of reducing training volume in smart set to prescribe optimal volume reductions, without implicating performance. HRV and HRRT may provide useful assessment tools for this research to determine adequate training stimuli and recovery. Moreover, resistance training has been shown to improve RE and performance by up to 7%, while reducing the risk of injury and biomechanical fatigue, although some reports meshing this, there is outstanding evidence in the literature that resistance training is beneficial at the elite level.In conclusion, it is recommended that after approp riate assessment, SIT and resistance training protocols are gradually introduced to Marks training regime. It is important to reduce total training volume during high intensity cycles of training, however suitable progression and test-re-test monitoring to track performance alterations is suggested in dress to track any decline in cardio-respiratory or musculoskeletal condition. Additionally a one to four yearly plan is recommended in order to develop Mark safely and effectively towards his 2016 Olympic goals.Word count 3340Table 2. Resistance training, alterations to running economy and endurance performance hit the booksSubjects(total number, caliber, gender)Training MethodFrequency and DurationVolumeControlRE (%)RP km%/secTurner et al., 200318 more or less trained comminglePlyometric Training3d/w x 6 wks1 set 5 25 repsRegular survival Running2.3*Spurrs et al., 20038Moderately trainedMalesPlyometric Training2-3d/w x 6 wk2 3 sets x 8-15 repsRegular Endurance Running5.7* 3km2.7%16 .6 secSaunders et al., 200615 extremely trainedPlyometric Training3d/w x 9 wk30 mins107 43 km of running per week 4.1*Berryman et al., 201035Highly trainedMalesPlyometric1 d/w x 8 weeks3 6 sets x 8 repetitionsEndurance Running 3 x per week7* 3km4.8%36 secPaavolanien et al. 199910Moderately trained Males run around Specific Explosive Strength Training2d/w x 9 wks15 90 minsEndurance running, circuit training8.1* 5k3.1%Mikkola et al., 200725Moderately trainedMixedExplosive Strength Training3d/w x 8 wks2 3 set x 6 -10 repetitionsEndurance RunningGuglielmo et al. 200916Highly trainedExplosive Strength2d/w x 4 wks3,4,5 x 12 RMEndurance training (60 80km.wk-1)Berryman et al., 201035Highly trainedMalesExplosive Training1 d/w x 8 weeks3 6 sets x 8 repetitionsEndurance Running 3 x per week 4% 3km4%31 secMillet et al., 200215Highly trainedMales (triathletes)Strength Training2d/w x 14 wk3-5 sets, 3 5 RMEndurance Training (Swim, Bike, Run) 5.6 7Storen et al., 200817Moderately trainedMixe dStrength Training8 wk4sets x 4RMRegular Endurance Running5Kelly et al., 200816RecreationalFemalesStrength Training3d/w x 10 week3 x 3 5 RMRegular Endurance running5.4 3km10691 secAPA vogue ReferencesACSM Guidelines for Exercise Testing and Prescription, 8th Edition, 2010. pp79, 83, 90 -92Acevedo, E. O., Goldfarb, A. H. (1989). Increased training intensity effects on plasma lactate, ventilatory threshold, and endurance. Medicine Science in Sports Exercise October, 21(5), 563-568.Berger, N. J. A., Campbell, I. T., Wilkerson, D. P., Jones, A. M. (2006). Influence of acute plasma volume expansion on VO2 kinetics, VO2peak, and performance during high-intensity cycle exercise. Journal of Applied Physiology, 101(3), 707-714.Berryman, N., Maurel, D., Bosquet, L. (2010). Effect of Plyometric vs. Dynamic encumbrance Training on the Energy Cost of Running. The Journal of Strength instruct Research, 24(7), 1818-1825 1810.Billat, V. L., Demarle, A., Slawinski, J., Paiva, M., Koralszt ein, J.-P. (2001). Physical and training characteristics of top-class marathon runners. Medicine