Secondary Logo

Journal Logo

Original Research

Physical Demands of Multimodal Training Competitions and Their Relationship to Measures of Performance

Jagim, Andrew R.1; Rader, Owen2; Jones, Margaret T.3; Oliver, Jonathan M.4

Author Information
Journal of Strength and Conditioning Research: May 2017 - Volume 31 - Issue 5 - p 1212-1220
doi: 10.1519/JSC.0000000000000992
  • Free

Abstract

Introduction

Multimodal training (MMT), a style of training purported to involve the performance of whole-body functional movements at varying intensities, is a popular recreational activity among fitness enthusiasts and has recently evolved into athletic competitions (32). However, at this time, the physiological demands of such MMT-style competitions are unknown. During MMT competitions, many individual events are staggered throughout the competition day. Few studies have been conducted on MMT training (30,34), and no study to date has examined a competition in which this type of training is performed. This may be due to the logistical challenges presented by the variation in exercises and nature of events, which have been touted to require flexibility, cardiovascular endurance, muscular endurance, strength, and power.

It is reported that the majority of MMT-style competitions incorporate multiple repetitions of externally loaded compound movements completed at high intensities with minimal rest requiring multiple physical attributes, suggesting that the competitions are highly anaerobic. From a physiological standpoint, there is no direct comparison as to what sport the physical demands or energy system involvement of MMT may be most similar. If a relationship was determined between certain physical characteristics and performance during competitions, it could provide insight into optimal training techniques and preparation. Understanding the physical characteristics and energy system involvement may facilitate the development of a specific training regimen aimed at improving those characteristics. Therefore, as its primary purpose, this study sought to identify the physical demands of an MMT-style competition.

A secondary purpose of this study was to examine the relationship between the identified physical demands and more traditional measures of athletic performance. Athletic performance-related testing has become popular across a variety of athletic and fitness settings. Appropriate tests may serve to predict on-field performance and permit strength and conditioning practitioners to document the results of a specific training program. For example, the National Football League has annual combine testing during which the top collegiate football players are invited to participate in certain drills, exercises, and tests, which are used to assess potential draft status and playing potential (33). Similarly, other sports, such as collegiate basketball and hockey, have used exercise tests to develop an athletic profile that may be best for their respective sports (12,21). The ability to predict performance outcomes using performance-based fitness tests may be beneficial to MMT trainers, coaches, and athletes by providing (a) insight into physical characteristics and training adaptations relevant to the sport, (b) a reference point for goal setting and program design, and (c) clarification of an individual's training status and performance potential. To the best of our knowledge, no one has investigated the physical demands of MMT-style competitions and their relationship to performance measures, making this study current and noteworthy. Therefore, our purpose was to (a) identify the physical demands of an MMT-style competition and (b) examine the relationship between those physical demands and selected measures of athletic performance.

Methods

Experimental Approach to the Problem

This study was designed to determine the physiological demands of an MMT-style competition and to examine the relationship between those physiological demands and selected measures of athletic performance. Individuals with experience performing MMT completed an initial baseline testing session, which consisted of body composition assessment, countermovement vertical jump, and test of maximal aerobic capacity. All participants then took part in a single simulated MMT-style competition on the same day within 2–10 days of their initial baseline testing. The competition consisted of 3 events separated by 90 minutes, with each event being completed in approximately 5–15 minutes. During each event, heart rate (HR), blood lactate, and ratings of perceived exertion (RPE) were measured to assess the physiological demands of the competition. Results of baseline testing and the 3 events were then used to determine if a relationship exists between traditional performance measures and the physiological characteristics of MMT.

Subjects

Participants were recruited from the local MMT community. Entrance criteria included having at least 6 months of training experience with MMT. During an informational session, potential participants were explained the details of the study. Ten men (n = 10) and 8 women (n = 8) (age: 37.8 ± 10.6 years, height: 172.8 ± 8 cm, weight: 77.4 ± 13.2 kg, 16.6 ± 6% body fat) volunteered to participate. Participants had no contraindications to exercise as evidenced by medical history questionnaire. All participants had the risks and benefits explained to them beforehand and signed an institutionally approved informed consent form to participate. The Institutional Review Board of Gannon University approved all procedures.

Baseline Testing

Body Composition

Height and body mass were determined to the nearest 0.1 cm and 0.1 kg, respectively, using a stadiometer (Seca, Chino, CA, USA) and Seca physicians' scale (Seca). Body composition was then assessed using air-displacement plethysmography (BODPOD; Cosmed, Chicago, IL, USA). Before each testing session, calibration procedures were completed according to the manufacturer's guidelines using an empty chamber and a calibrating cylinder of a standard volume (49.55 L). Subjects were instructed to refrain from eating for 2 hours and exercising for at least 8 hours before testing, wear spandex or tight-fitting clothing, remove all jewelry, and wear a swim cap while undergoing testing. Subjects were instructed to sit motionless in the fiberglass chamber using normal breathing patterns while the BOD POD was sealed with magnetic locks, and body volume was measured. Lung volume was directly assessed for determination of relative body volume based on thoracic volume. The participant's body mass and body volume were then used to estimate body fat composition based on the Brozek equation (8). Previous studies indicate air-displacement plethysmography to be an accurate and reliable means to assess changes in body composition (26).

Countermovement Vertical Jump

Before testing, participants completed a 10-minute dynamic warm-up consisting of 6 body weight movements. Next, participants completed countermovement vertical jump (CMVJ) testing using a commercially available Vertec jump system (Sports Imports, Columbus, OH, USA). First, standing reach height was recorded followed by 3 CMVJ jump attempts, with 2-minute rest in between each. If the third attempt was greater than the first 2, another attempt was allowed until a decrease in jump height was observed, with a maximum of 5 attempts allowed. The maximum attempt of record was later converted to peak and mean power in watts using previously described procedures (18).

Aerobic Capacity

Aerobic capacity was assessed using a Quinton Multitrack ST55 diagnostic treadmill (Quinton Instrument Company, Bothell, WA, USA) and a Parvo Medics TrueOne 2400 Metabolic Measuring System Gas Analyzer (Parvo Medics, Inc., Salt Lake City, UT, USA). Quality control and calibration procedures were performed daily before testing using standard medical grade gases and a 3.0 L syringe for flowmeter. The Bruce treadmill (17) protocol was used for the assessment of aerobic capacity, and participants were instructed to continue the test until they reached volitional fatigue. True maximal aerobic capacity was determined if at least 2 of the following criteria were met: (a) peak respiratory exchange ratio was above 1.1, (b) measured HRmax was within 10 b·min−1 of age-predicted HRmax, and (c) oxygen consumption increase was <150 ml·min−1 between the final 2 stages.

Test Protocol

Within 2–10 days of their initial baseline testing session, participants returned to the laboratory to perform an MMT-style competition. Participants had been instructed to refrain from any activity outside daily living for the preceding 24 hours. Additionally, all participants were asked to follow normal precompetition preparation to include any prestretching, warm-up, and dietary intake. The testing began at 0900. Because of the number of participants, groups of 4–6 performed the MMT-style competition at the same time, separated into heats.

Events 1–3 were separated by 90 minutes each from the start of the previous event. A summary of the individual events used in the MMT-style competition is presented in Table 1.

Table 1.
Table 1.:
Summary of simulated competition events.*

Briefly, the objective of event 1 was to complete 3 rounds of 3 exercises as fast as possible (Table 1, event 1). Participants had the option of “scaling” the weight used for kettle bell swings to allow them to complete the event. Participants chose either a 24-or 16-kg kettle bell. Similar scaling options were available for the pull-ups, as participants had the option of completing the pull-ups with assistive bands (n = 3). Event 2 was a 1 repetition maximum (1RM) front thruster (squat-to-overhead press) challenge during which participants had 5 minutes to achieve their 1RM for thrusters using as many attempts as necessary. Research personnel observed the form and technique of each repetition and recorded the corresponding weight. Event 3 required participants to complete 10 repetitions of each of the exercises listed in Table 1 (i.e., event 3) as fast as possible for time in that order. Men used 43 kg for all exercises and women used 30 kg. Before each event, baseline HR, lactate, and RPE were obtained for each participant.

Heart Rate

A Polar FT1 HR monitor (Polar Electro Inc., Lake Success, NY, USA) and Polar T3 1-Coded chest strap recorded HR every 30 seconds throughout the competition. These data were later used to determine energy expenditure throughout each event using a regression equation developed from the HR values and corresponding energy expenditures collected during the initial aerobic capacity test during baseline testing (37).

Lactate

Lactate was assessed using Nova Biomedical Lactate Plus (Nova Biomedical Corporation, Waltham, MA, USA) reader and test strips. Samples were collected using Mumford Unistick 3 (Owen Mumford, Oxford, United Kingdom) normal single-use safety lancets before each event and immediately after.

Ratings of Perceived Exertion

Ratings of perceived exertion were assessed using Borg's category scale of perceived exertion in which scores range from 6 to 20 (7). Subjects were asked every minute throughout each event to provide a number corresponding to their current level of exertion on the scale. Research personnel collected participants' time to completion for events 1 and 3. Ninety-minute rest was allotted between each cross-fit–based MMT bout, which was monitored by research personnel. The same techniques and protocols were used for each event until participants completed the final event of the simulated competition event.

Statistical Analyses

Descriptive statistics (mean ± SD) were computed for all physical characteristics, physiological responses, and performance-based fitness measures. Delta values were calculated and analyzed on select variables. Bivariate (Pearson) correlations were computed to determine possible significant relationships among variables. Alpha was set at p ≤ 0.05 to achieve statistical significance. Moderate correlations were defined as R values of 0.41–0.70, and strong correlations were considered to be between 0.71 and 0.90 (22). All analyses were conducted using the Statistical Package for the Social Sciences (SPSS, Version 20; SPSS Inc., Chicago, IL, USA).

Results

A baseline summary of the physical characteristics for all participants is presented in Table 2. The average time (mean ± SD) to completion for event 1 was 675.7 ± 104.3 seconds and 438.8 ± 79.4 seconds for event 3. The average 1RM thruster during event 2 was 75.0 ± 27.8 kg. Table 3 represents the summary of physiological responses during each event.

Table 2.
Table 2.:
Physical characteristics of participants.*
Table 3.
Table 3.:
Summary of physiological responses to 3 MMT-style events.*

Relationships between physiological responses and measures of performance during event 1 are presented in Table 4. Strong correlations were observed between time to completion and aerobic capacity and for time to completion and body fat percentage. Strong negative correlations were observed between fat-free mass and time to completion and between lower-body peak and mean power as determined from CMVJ and time to completion. A moderate correlation was observed for fat-free mass and the change in lactate during event 1.

Table 4.
Table 4.:
Relationship between physiological responses and measures of performance during event 1.*

Relationships between physiological responses and measures of performance during event 2 are included in Table 5. A strong correlation was observed between lower-body peak and mean power as determined from CMVJ fat-free mass and 1RM thrusters. A moderate correlation was observed between aerobic capacity and 1RM thruster. A moderate negative correlation was observed between body fat percent and 1RM thrusters.

Table 5.
Table 5.:
Relationship between physiological responses and measures of performance during event 2.*

Relationships between physiological responses and measures of performance during event 3 are presented in Table 6. A strong negative correlation was observed between lower-body peak and mean power as determined from CMVJ, fat-free mass, and time to completion.

Table 6.
Table 6.:
Relationship between physiological responses and measures of performance during event 3.*

Discussion

The main purposes of this study were to (a) identify the physiological demands of an MMT-style competition and (b) examine the relationship between those physiological demands and selected measures of athletic performance. As previously noted, no one has investigated the physical demands of MMT-style competitions, making this study current and noteworthy.

The MMT style of training can perhaps best be described as a hybrid of high-intensity interval training and resistance training that uses varied multiple joint movements (34). The MMT events and competitions are relatively short in comparison with traditional sporting events and may be more analogous to circuit training or sports in which multiple timed rounds or bouts of high-intensity intervals are performed, such as wrestling or combat sports. In this study, the participants completed the timed events 1 and 3 in approximately 11 and 7 minutes, respectively. However, in between the events, there was a timed rest period of 90 minutes. These times are similar to completion times reported in previous research involving comparable MMT-style events (2,30). Previous research has examined the differences in physiological and metabolic responses to various modes of exercise such as weightlifting, circuit training (10,16,19,28,29,31,38,40), and combat-based sports (1,6,9,11,14,23). Barbas et al. (4) reported mean HR values ranging from 180 to 190 following matches of Greco-Roman wrestling during a simulated 1-day tournament. Beckham and Earnest (5) reported mean HR values of 120–130 b·min−1 (55–60% of HRmax) during 50 minutes of free-weight circuit training. Likewise, Collins et al. (13) reported mean HR values between 120 and 150 b·min−1 during various weightlifting exercises. The mean HR values observed in this study ranged between 167 and 172 b·min−1 (80–95% of HRmax) for the timed events 1 and 3, which are indicative of high-intensity exercise albeit below the HR values reported during combat sports (14,23) but higher than those reported during circuit-based resistance exercise (5,29,35).

In this study, oxygen consumption and energy cost were estimated using a previously validated procedure (37). When compared with those reported for combat sports, the estimated relative mean V̇O2 values in this study are below those typically reported. For example, Campos et al. (9) reported relative mean V̇O2 values during competition ranging from 44 to 53 ml·kg−1·min−1 during a taekwondo combat, which is approximately 65% above the 24–35 ml·kg−1·min−1 observed in this study. However, when comparing energy expenditures, the differences between MMT-style competitions and combat sports seem to dissipate. For example, Crisafulli et al. (14) reported energy expenditures ranging from 12 to 15 kcal·min−1 during a simulated Muay Thai boxing match, which is comparable with the range of 10–15 kcal·min−1 observed in this study. When compared with strength-based circuit training, the energy expenditures observed in this study are higher than those reported previously reported (10–15 vs. 4–6 kcal·min−1) (5), which may be attributable to the incorporation of more multijoint compound movements.

Similar comparisons can be made when examining the blood lactate response. The mean change in blood lactate values for the timed events 1 and 3 in this study was 10–12 mmol·L−1, which suggests that the events were highly anaerobic in nature. Barbas et al. (4) observed changes in lactate ranging from 13 to 17 mmol·L−1 before and after matches during a simulated wrestling tournament. Kraemer et al. (20) observed changes in blood lactate levels above 15–20 mmol·L−1 in Division I wrestlers before and after individual matches, which lasted approximately 5 minutes, during a 2-day tournament. The greatest change in lactate occurred immediately after the first match of the tournament, which is similar to the findings in this study. Therefore, it appears as though MMT-style competitions are comparable in nature with combat sports in terms of time requirements yet do not stress the cardiovascular or metabolic systems to the same extent.

A secondary purpose of this study was to determine if a relationship exists between traditional measures of performance and those of an MMT-style competition. A significant correlation was observed between measures of lower-body power and performance in event 1. In addition, aerobic capacity and fat-free mass were also associated with faster times to completion in event 1. Event 1 consisted of 2 strength-based activities interspersed with a high-intensity anaerobic run. Therefore, it would be expected that a higher aerobic capacity and measures of lower-body power would improve performance. Similarly, a greater lower-body peak power and higher amount of fat-free mass were characteristics that were associated with better performance in event 3, which consisted of several strength-based exercises.

Fat-free mass was positively associated with lower-body strength as determined by 1RM thruster performance in event 2. Previous research has reported this relationship in both trained (15,24) and untrained (25,39) individuals. In addition, lower-body peak and average power were positively associated with lower-body strength in this study. The relationship between lower-body strength and power has been observed previously in a variety of different populations (3,36). In support, Baker and Nance (3) observed a strong relationship between maximal strength and power in professional rugby players. Similarly, Stone et al. (36) observed a significant correlation between back squat 1RM and squat jump power in recreationally trained males. Indices of lower-body strength have been shown to be correlated with measurements of lower-body power and may offer a convenient method of predicting lower-body power and performance (36). Similar to traditional strength- and power-based sports, it appears as though lower-body strength, power, and fat-free mass are associated with greater performance in MMT-style competitions.

We acknowledge some study limitations. First, the MMT-style competition was simulated, and therefore, the results may have been different if the variables had been measured during an actual competition event. Second, the subjects' age range (21–52 years) may have influenced the physiological responses (27) to some of the events; however, this is beyond the scope of this study. Although the results of this study provide insight into the physiological demands of MMT-style competitions, further research on this topic is warranted.

In conclusion, MMT-style competitions are physically demanding activities performed at a high intensity with a great involvement of the anaerobic energy system and moderate recruitment of the aerobic energy system. As MMT-style competitions do not tax the anaerobic energy system to the same extent as combat sports, performance may be more dependent on the aerobic energy system. Additionally, individuals with a high lean body mass and greater lower-body power may be best suited for this type of physical activity.

Practical Applications

It is recommended that strength and conditioning programs with the goal of improving lean body mass and lower-body power are a priority for those practitioners who are training competitive MMT athletes. It is also suggested that strength-based compound movements be performed at high intensities with limited recovery periods to facilitate adequate preparation for subsequent competition. The inclusion of conditioning activities with the specific goal of improved aerobic capacity is recommended to assist with performance in timed events.

References

1. Amtmann JA, Amtmann KA, Spath WK. Lactate and rate of perceived exertion responses of athletes training for and competing in a mixed martial arts event. J Strength Cond Res 22: 645–647, 2008.
2. Babiash PE. Determining the energy expenditure and relative intensity of two crossfit workouts. In: Exercise and Sport Science—Clinical Exercise Physiology. La Cross, WI: University of Wisconsin–La Crosse, 2013.
3. Baker D, Nance S. The relation between strength and power in professional rugby league players. J Strength Cond Res 13: 224–299, 1999.
4. Barbas I, Fatouros IG, Douroudos II, Chatzinikolaou A, Michailidis Y, Draganidis D, Jamurtas AZ, Nikolaidis MG, Parotsidis C, Theodorou AA, Katrabasas I, Margonis K, Papassotiriou I, Taxildaris K. Physiological and performance adaptations of elite Greco-Roman wrestlers during a one-day tournament. Eur J Appl Physiol 111: 1421–1436, 2011.
5. Beckham SG, Earnest CP. Metabolic cost of free weight circuit weight training. J Sports Med Phys Fitness 40: 118–125, 2000.
6. Beneke R, Beyer T, Jachner C, Erasmus J, Hutler M. Energetics of karate kumite. Eur J Appl Physiol 92: 518–523, 2004.
7. Borg G. Ratings of perceived exertion and heart rates during short-term cycle exercise and their use in a new cycling strength test. Int J Sports Med 3: 153–158, 1982.
8. Brozek J, Grande F, Anderson JT, Keys A. Densitometric analysis of body composition: Revision of some quantitative assumptions. Ann N Y Acad Sci 110: 113–140, 1963.
9. Campos FA, Bertuzzi R, Dourado AC, Santos VG, Franchini E. Energy demands in taekwondo athletes during combat simulation. Eur J Appl Physiol 112: 1221–1228, 2012.
10. Carter R III, Watenpaugh DE, Smith ML. Gender differences in cardiovascular regulation during recovery from exercise. J Appl Physiol (1985) 91: 1902–1907, 2001.
11. Chiodo S, Tessitore A, Cortis C, Lupo C, Ammendolia A, Iona T, Capranica L. Effects of official Taekwondo competitions on all-out performances of elite athletes. J Strength Cond Res 25: 334–339, 2011.
12. Clarke DH, Wrenn JP, Vaccaro P. Muscular performance and body size characteristics of elite collegiate basketball players. Am Correct Ther J 33: 178–183, 1979.
13. Collins MA, Cureton KJ, Hill DW, Ray CA. Relationship of heart rate to oxygen uptake during weight lifting exercise. Med Sci Sports Exerc 23: 636–640, 1991.
14. Crisafulli A, Vitelli S, Cappai I, Milia R, Tocco F, Melis F, Concu A. Physiological responses and energy cost during a simulation of a Muay Thai boxing match. Appl Physiol Nutr Metab 34: 143–150, 2009.
15. Davis S, Briscoe D, Markowski C, Saville S, Taylor C. Physical characteristics that predict vertical jump performance in recreational male athletes. Phys Ther Sport 4: 167–174, 2003.
16. Deschenes MR, Hillard MN, Wilson JA, Dubina MI, Eason MK. Effects of gender on physiological responses during submaximal exercise and recovery. Med Sci Sports Exerc 38: 1304–1310, 2006.
17. Froelicher V, Thompson A, Davis G, Triebwasser J. Prediction of maximal oxygen consumption: Comparison of the Bruce and Balke treadmill protocols. Chest 68: 331–336, 1975.
18. Johnson D, Bahamonde R. Power output estimate in university athletes. J Strength Cond Res 10: 161–166, 1996.
19. Korhonen MT, Suominen H, Mero A. Age and sex differences in blood lactate response to sprint running in elite master athletes. Can J Appl Physiol 30: 647–665, 2005.
20. Kraemer WJ, Fry AC, Rubin MR, Triplett-McBride T, Gordon SE, Koziris LP, Lynch JM, Volek JS, Meuffels DE, Newton RU, Fleck SJ. Physiological and performance responses to tournament wrestling. Med Sci Sports Exerc 33: 1367–1378, 2001.
21. Krause DA, Smith AM, Holmes LC, Klebe CR, Lee JB, Lundquist KM, Eischen JJ, Hollman JH. Relationship of off-ice and on-ice performance measures in high school male hockey players. J Strength Cond Res 26: 1423–1430, 2012.
22. Mangal SK. Statistics in Psychology and Education. New Delhi, India: PHI Learning, 2010.
23. Matsushigue KA, Hartmann K, Franchini E. Taekwondo: Physiological responses and match analysis. J Strength Cond Res 23: 1112–1117, 2009.
24. Mayhew J, Piper F, Schwegler T, Ball T. Contributions of speed, agility and body composition to anaerobic power measurement in college football players. J Appl Sport Sci Res 3: 101–106, 1989.
25. Mayhew JL, Hancock K, Rollison L, Ball TE, Bowen JC. Contributions of strength and body composition to the gender difference in anaerobic power. J Sports Med Phys Fitness 41: 33–38, 2001.
26. McCrory MA, Gomez TD, Bernauer EM, Molé PA. Evaluation of a new air displacement plethysmograph for measuring human body composition. Med Sci Sports Exerc 27: 1686–1691, 1995.
27. Ogawa T, Spina RJ, Martin WH III, Kohrt WM, Schechtman KB, Holloszy JO, Ehsani AA. Effects of aging, sex, and physical training on cardiovascular responses to exercise. Circulation 86: 494–503, 1992.
28. Ohkuwa T, Miyamura M, Andou Y, Utsuno T. Sex differences in lactate and glycerol levels during maximal aerobic and anaerobic running. Eur J Appl Physiol Occup Physiol 57: 746–752, 1988.
29. Ortego AR, Dantzler DK, Zaloudek A, Tanner J, Khan T, Panwar R, Hollander DB, Kraemer RR. Effects of gender on physiological responses to strenuous circuit resistance exercise and recovery. J Strength Cond Res 23: 932–938, 2009.
30. Patel P. The influence of a crossfit exercise intervention on glucose control in overweight and obese adults. In: Department of Kinesiology. Manhattan, KS: Kansas State University, 2012.
31. Ricciardi R, Deuster PA, Talbot LA. Effects of gender and body adiposity on physiological responses to physical work while wearing body armor. Mil Med 172: 743–748, 2007.
32. Rishe P. CrossFit's relationship with Reebok enhances its financial and commercial credibility. Forbes, 2011.
33. Robbins DW. The national football league (NFL) combine: Does normalized data better predict performance in the NFL draft? J Strength Cond Res 24: 2888–2899, 2010.
34. Smith MM, Sommer AJ, Starkoff BE, Devor ST. Crossfit-based high-intensity power training improves maximal aerobic fitness and body composition. J Strength Cond Res 27: 3159–3172, 2013.
35. Stanforth D, Stanforth PR, Hoemeke MP. Physiologic and metabolic responses to a body pump workout. J Strength Cond Res 14: 144–150, 2000.
36. Stone MH, O'Bryant HS, McCoy L, Coglianese R, Lehmkuhl M, Schilling B. Power and maximum strength relationships during performance of dynamic and static weighted jumps. J Strength Cond Res 17: 140–147, 2003.
37. Strath SJ, Swartz AM, Bassett DR Jr, O'Brien WL, King GA, Ainsworth BE. Evaluation of heart rate as a method for assessing moderate intensity physical activity. Med Sci Sports Exerc 32: S465–S470, 2000.
38. Szivak TK, Hooper DR, Dunn-Lewis C, Comstock BA, Kupchak BR, Apicella JM, Saenz C, Maresh CM, Denegar CR, Kraemer WJ. Adrenal cortical responses to high-intensity, short rest, resistance exercise in men and women. J Strength Cond Res 27: 748–760, 2013.
39. Thomas M, Fiatarone MA, Fielding RA. Leg power in young women: Relationship to body composition, strength, and function. Med Sci Sports Exerc 28: 1321–1326, 1996.
40. Zehnder M, Ith M, Kreis R, Saris W, Boutellier U, Boesch C. Gender-specific usage of intramyocellular lipids and glycogen during exercise. Med Sci Sports Exerc 37: 1517–1524, 2005.
Keywords:

performance correlations; countermovement vertical jump; aerobic capacity

© 2015 National Strength and Conditioning Association