Small-Sided Games in elite soccer: Does one size fits all?

Lacome M., B.M. Simpson, Y. Cholley, P. Lambert, and M Buchheit. Small-Sided Games in elite soccer: Does one size fits all? IJSPP, In press 2017.

Full Text here

Abstract

Purpose: To compare the peak intensity of typical Small Sided Games (SSGs) with those of official matches in terms of running demands and mechanical work over different rolling average durations and playing positions.

Method: Data were collected in 21 players (25±5 y, 181±7 cm, 77±7 kg) belonging to an elite French football team. SSG data were collected over two seasons during typical training sessions (249 files, 12±4 per player) and official matches (n=12). Players’ locomotor activity was recorded using 15-Hz GPS. Total distance (TD, m), high-speed distance (HS, distance above 14.4 km.h-1, m) and mechanical work (MechW, a.u) were analysed during different rolling average periods (1 to 15 min). The SSGs examined were 4v4+Goal Keepers (GKs), 6v6+GKs, 8v8+GKs and 10v10+GKs.

Results: Peak TD and HS during 4v4, 6v6 and 8v8 were likely-to-most likely largely lower than during matches (ES: -0.59,±0.38 to -7.36,±1.20). MechW during 4v4 was likely-to-most likely higher than during matches (1-4-min; 0.61±,0.77 to 2.30±,0.64). Relative to their match demands, central defenders (CD) performed more HS than other positions (0.63±,0.81 to 1.61±,0.52) during 6v6. Similarly, central midfielders (CM) performed less MechW than the other positions during 6v6 (0.68,±0.72 to 1.34,±0.99) and 8v8 (0.73,±0.50 to 1.39,±0.32).

Conclusion: Peak locomotor intensity can be modulated during SSGs of various formats and durations to either over- or underload match demands, with 4v4 placing the greatest and the least emphasis on MechW and HS, respectively. Additionally, CD and CM tend to be the most and least overloaded during SSGs, respectively.

Key words: Small sided games, soccer, peak intensity, match demands, periodisation,

 

SSG_Figure2 (600)2

Peak locomotor intensity during the different small-sided games compared with match demands as a function of each rolling average period for all players pooled together (grey zones stand for match average ± standard deviations). Confidence intervals for mean values are not provided for clarity.

@mathlacome

Heart rate-based versus speed-based high-intensity interval training in young soccer players

Rabbani and M. Buchheit. Heart rate-based versus speed-based high-intensity interval training in young soccer players. International Research in Science and Soccer II, 2015, In press

Full text here

HR vs Speed based HIT

Abstract

While heart rate (HR) is often used to control exercise intensity during high-intensity interval training (HIT), this approach has several limitations, including the difficulty for practitioners to regulate running intensity. To overcome these limitations, using the speed reached at the end of the 30-15 Intermittent Fitness Test (VIFT) as the reference for running intensity has been suggested. The aim of the present study was to compare the effect of HR- vs. VIFT-based HIT on high-intensity intermittent running performance in young soccer players. Twenty two soccer players (15.12 ± 0.5 yrs) were divided in two different experimental groups including HR-based (n=10) or VIFT-based (n=12) HIT during their preseason preparation. The VIFT-based HIT group performed a 30-15 Intermittent Fitness Test before the intervention to detect player’s VIFT. All players performed a Yo-Yo Intermittent Recovery Test level 1 (YYIRT1) before and after the intervention. All players underwent the same conditioning and technical/tactical training programs for 4-5 weeks, except the method of individualizing soccer-specific HIT sessions with the ball (2 sessions of HIT=3 sets of 3:30 min): either according to 90-95% of maximal HR, or 65-70% VIFT. We then compared the between-group differences in weekly improvement in YYIRT1 using magnitude-based inferences. VIFT-based HIT produced likely greater weekly improvement in YYIRT1performance than HR-based HIT (+86%, 90%CL (1.5- 240%); standardized difference: +0.7(0.02- 1.40), chances for greater/similar/lower values of 95/4/1). Using VIFT as a reference speed for HIT programming may elicit greater high-intensity intermittent running performance improvements than using percentages of maximal HR in young soccer players.

Key words: high-intensity running programming; training individualization; high-intensity running performance; 30-15 Intermittent Fitness Test.

Ali

@alirezarabbani

Dr Boullosa’s forgotten pieces don’t fit the puzzle

Martin Buchheit and Paul B. Laursen

(to be published soon in Sports Med in response to Dr Boullosa’s letter)

We appreciate the opportunity to respond to Dr Boullosa’s letter of concern [1] on issues brought forth in our 2-part review on high-intensity interval training (HIT) [2, 3]. However, we were surprised to read the letter’s content, feeling generally that most comments were off-topic, and accordingly offering little to assist the practitioner. Nevertheless, we will use this opportunity to elaborate on certain principles and in doing so outline why his so-called ‘forgotten pieces’ do not fit the training program puzzle.

 

His first critique of our review [2] was that there was no comment as to how progressive exercise test protocol design influences the relationship between the velocity/power at maximal oxygen uptake (v/pO2max) and performance. This is simply incorrect. Section 2.5 of our review extends to more than a full page of printed text describing in detail the history, theory, as well as measurement techniques practitioners can perform in both the laboratory and the field to determine appropriate values, as well as their limitations. We state clearly how “vO2max [determination] is method-[4] and protocol-dependent [5]”. It would therefore be implied that the magnitude of the relationship between vO2max and performance would comparatively be affected. We did not elaborate further on this point, as such discourse would be superfluous within the context of the review, which focused on HIT prescription, and not performance prediction. For these reasons, Dr Boullosa’s first piece doesn’t fit.

 

His second critique was that “there was no reference […] to how [anaerobic speed reserve] ASR could be influenced by the method [used] for [maximal sprinting speed] MSS determination”. While the point is valid, there are a limited number of known methods for determining MSS, and these unlikely produce differences in MSS as great as those seen with vO2max or the final speed reached during incremental test (VIncTest­) [2]. In practice, the use of a flying 10- [6] or 20-m [7, 8] time is probably the most common method of determination, although peak instantaneous speed can also be measured now with radar gun technology [9]. The difference between these methods is generally less than ~2% (personal observations), which is substantially lower than the possible ~20% difference that can be observed for vO2max/VIncTest determination [2]. Moreover, the typical error of measurement for MSS (1%) is also clearly lower than that of VIncTest (3.5%) [10]. Taken together, these data show that the determination of ASR is less likely to be affected by variations in MSS compared with vO2max/VIncTest estimation, and explain why we chose against elaborating further on this point in our review [2].

 

Dr Boullosa goes on to claim that “the practicality of the 30-15 Intermittent Fitness Test (30-15IFT) for evaluating simultaneously different locomotor abilities and ASR is contradictory stricto sensu with the previous definition of ASR”, and offers instead “a potentially simple and time-saving alternative evaluation of ASR with the recording of a maximum sprint test performed 3-5 min after an incremental test for vO2max determination [7].” The first part of the comment is unclear to us, since it is now known that VIFT is sensitive to both vO2max/VIncTest and MSS [11]. The ‘dual sensitivity’ of the 30-15IFT motivated our comments around the ‘simultaneous’ evaluation of different locomotor abilities. We showed that while the first determinant of VIFT is vO2max/VIncTest, MSS is likely to be the secondary influencing variable [11]. If we take, for example, two young football players presenting with similar v O2max/VIncTest scores, the athlete with the faster MSS also has the faster VIFT (Figure 1, personal data). The other part of Dr Boullosa’s comment suggesting assessment of MSS following the incremental test is also at odds with the current practices that we are personally aware of, both for team sports and distance running. While standing [12] and flying [7, 8] 20-m sprint tests have been used in the literature with endurance athletes after exhaustive exercise, such procedures are problematic for assessing MSS (i.e., 10-m splits likely allow a better assessment compared with 20-m ones, and the fastest split is not necessarily derived from the last one [6]). Since athletes must sprint maximally over at least 40-to-50m to ensure their MSS is captured, coaches (irrespective of the sport) tend to be (in our experience) reluctant to assess MSS post-incremental test, mainly due to the increased hamstring and adductor injury risk [13]. The assessment of MSS following an incremental test is also questionable from a performance standpoint, since MSS could potentially be impaired, especially in team-sport athletes. While some endurance athletes might maintain sprinting speed [14], the magnitude of the performance decrement post-exhaustive effort is largely and inversely correlated with initial sprinting speed [8]; faster team sport players therefore would likely incur a large impairment to MSS using such an approach. Since this potentially serious effect is athlete-background and locomotor profile-dependent, it makes more sense practically to assess MSS on a separate occasion, when all athletes have recovered from the vO2max/VIncTest [11, 15]. In light of these arguments, we believe Dr Boullosa’s second piece does not fit the puzzle.

 

In Dr Boullosa’s third critique, he states that “there is no actual evidence supporting the usefulness of ASR for individualizing training intensity prescription.” While we agree that a comprehensive study comparing the acute and long-term physiological and performance responses of HIT sessions based on vO2max/VIncTest vs. %ASR has yet to be published, we can provide evidence to support the use of this method to individualize HIT (Figure 2). First, the approach is used across a considerable number of (team) sports worldwide, and has been now for more than 10 years, which is proof of its practicality, interest and usefulness (i.e., ‘best practice’ theory). Second, the ASR approach is taught in well-established and respected strength and conditioning courses throughout the world (e.g., France, Spain, Italy, Germany, Switzerland, USA, Australia, New Zealand), and has been the subject matter of publications by other groups (e.g., [16]). Last, as with the smaller between-athlete variations in acute cardiac responses to VIFT vs. vO2max/VIncTest -based HIT sessions [17], we have observed a smaller between-athlete variation in time-to-exhaustion using % of ASR compared to % of v O2max/VIncTest (31 vs. 55% during a 15s @ 95% VIFT / 15s passive HIT, unpublished data). This clearly shows that using the entire locomotor profile (or at least VIFT) to prescribe running-based HIT with short intervals, rather than only vO2max, allows the standardisation of relative exercise intensity at the individual level. The direct consequence of this intensity standardisation is that the work interval duration represents a constant fraction of the predicted time to exhaustion at this relative intensity for all athletes. Along these lines, the number of work intervals required to match the predicted supramaximal distance capacity remains also constant for all athletes (Figure 2).

Figure 1

Figure 2 updated proof

Dr Boullosa goes on to emphasize that “the improvement of both MSS and vO2max are independent objectives that depend on the requirements of a specific sport”. We of course concur, as we highlighted in Figure 1 from the first part of our review [2], where we outline how training objectives should relate to the athlete’s profile, sport and training cycle. But we did not suggest that variation in HIT formats can be used specifically to improve either MSS or vO2max in isolation. It is clear that if the training objective is to improve MSS, isolated speed/strength sessions would be recommended, and not HIT sessions [18, 19], as shown also in Figure 1 of the first part of the review [2]. In addition, the remaining part of Dr Boullosa’s comment, where reference is made to acceleration capacity in team sports, shows that he fails to consider separately the physiological and neuromuscular requirements of 1) a given training session aimed at improving an athlete’s physiology and 2) competitive situations. While the principle of training specificity should not be forgotten, excessive reliance on competition-like training content (e.g., match replication) has its limitations [20, 21]. The main interest in determining ASR is to account for the athletes’ entire locomotor profile when performing a run-based HIT session at high but not maximal speed, which has implications for acute physiological and performance responses during the session (see previous point), irrespective of the sport demands. Similarly, the value of maximal acceleration capacity, although unlikely to be reached during HIT, may eventually be considered with respect to the frequent start-and-stop requirements of HIT with short intervals [22], but again, without direct link to the actual sport demands. Finally, while MSS is not often reached during matches [23], a faster MSS likely reduces relative neuromuscular load [15, 24], which may improve exercise tolerance and lower injury risk. Along these lines, although outside the scope of our review, the development of MSS as a training focus for team sport athletes makes logical sense, and is probably as important as acceleration capacity. Regardless, we again have an odd-shaped puzzle piece offering from Dr Boullosa’s that we can’t make fit.

 

He further states that we have a “misunderstanding [of] post-activation potentiation (PAP) after different HIT modalities”, where we suggest that “around vO2max intensities PAP would be maximized, thus favoring a positive neuromuscular loading”. Dr Boullosa might have himself misunderstood our conclusions, since we were not implying a causal link between the potential PAP effect and positive neuromuscular loading. We in fact refer to “long-term structural adaptations that allow fatigue-resistance to high-speed running [25]” as a separate mechanism (section 2.2.6). Indeed, the 80% of vO2max threshold he refers to for maximising PAP actually falls within the blue zone of our Figure 5 in the second part of the review (~80-85% v O2max, see text in the 2.2.6 section [3]). While his suggestion of a likely beneficial effect of recovery intervals for neuromuscular fatigue development during HIT may be true when comparing continuous versus intermittent incremental tests, the results we show in Figure 2 (b panel) from the 2nd part of our review suggest otherwise [3]. For instance, the repeated-sprint exercise (5s/25s) associated with the greater CMJ performance impairment, included a longer relief interval than the HIT with short interval session (10s/20s), where an increase, and not a decrease in CMJ performance was observed. This suggests that the neuromuscular responses to high-intensity exercise may reflect the combined influence of both work and relief interval characteristics, with work interval intensity the likely major contributor. Indeed, it is well established that it is the intensity and duration of the work interval, and not the average HIT intensity, that determines the largest portion of the physiological, perceptual and performance responses to a given HIT session [26-29]. Following these lines, the mention by Dr Boullosa of the so-called ‘new’ equation proposed by Tschakert and Hofmann (already proposed by Billat nearly 15 years ago [30]) aimed at equating HIT sessions based on external workload, also becomes a puzzle piece that will not interlock.

 

Dr Boullosa ends his letter stating how “the practicality of the [HIT] programming examples provided in [our] review [are] limited without knowing the outcomes of different physical capacities” and that “it is necessary to study […] the whole training workload [and] consider the […] other training exercises, including any form of physical activity as recently suggested [31].” His first comment is perplexing to us, since the four HIT programming examples we provided from different elite sport athlete programs (Tables 4 to 7 of the second part of the review [3]) were shown over different training cycles, so as to illustrate how HIT manipulation can be related to different physiological (e.g., VO2 development) and performance phases. Providing more detailed recommendations would, of course, be hazardous, and, in fact, impossible, since there would be as many options for training program content as there are athletes in the world (Figure 1 of the first part of the review [2]). The idea of considering the “whole training workload” is reflected throughout our review, where we consistently emphasize how HIT programming needs to be considered within the context of all training content, from skill and speed/strength sessions, to low intensity continuous work, to threshold sessions, to O2 work, to supramaximal training, to individual athlete characteristics, to recovery, etc. – this, of course, is the complex and dynamic “Puzzle” we continually strive to solve! Reference made by Dr Boullosa to the single study of Faude et al. [32], suggesting a greater benefit of high volume training compared with HIT, is at odds with his aforementioned comment on the presumed importance of equated external workload amongst training sessions, as training load was in fact more than 70% greater in the high volume training compared with the HIT group. As cited by Dr Boullosa himself in one of his own publications [33], there are dozens of other studies showing the more favourable responses with HIT. If we were to reference a single study of best practice today, we would quote that of Stoggl and Sperlich, who concluded that a mixture of all types of training may be the most efficient approach [34]. Finally, the last sentence of Dr Boullosa’s letter, referring again to his work [31] brings up our last point, whereby throughout his letter there appears to be an undue emphasis on his own work (40% of cited papers in his letter [1]), since the importance of actual physical activity as an interference mechanism with respect to longitudinal adaptations was suggested more than 10 years ago in adults [35] and children [36] subjected to a training intervention.

 

While we appreciate the opportunity that Dr Boullosa’s letter has provided to us to explain further some of the concepts within our 2-part review, we hope we have made clear how his so-called forgotten pieces do not fit within a practitioner’s training program puzzle.

 

References

 

  1. Boullosa DA. The forgotten pieces of the high intensity interval training

Puzzle. Sports Med. 2014: In press.

  1. Buchheit M and Laursen PB. High-intensity interval training, solutions to the programming puzzle: Part I: cardiopulmonary emphasis. Sports Med. 2013;(43):313-338.
  2. Buchheit M and Laursen PB. High-intensity interval training, solutions to the programming puzzle. Part II: anaerobic energy, neuromuscular load and practical applications. Sports Med. 2013: In press.
  3. Hill DW and Rowell AL. Running velocity at VO2max. Med Sci Sports Exerc. 1996;(28):114-119.
  4. Midgley AW, McNaughton LR, and Carroll S. Time at VO2max during intermittent treadmill running: test protocol dependent or methodological artefact? Int J Sports Med. 2007;(28):934-939.
  5. Buchheit M, Simpson BM, Peltola E, et al. Assessing maximal sprinting speed in highly-trained young soccer players. Int J Sports Physiol Perform. 2012;(7):76-78.
  6. Boullosa DA, Tuimil JL, Alegre LM, et al. Concurrent fatigue and potentiation in endurance athletes. Int J Sports Physiol Perform. 2011;(6):82-93.
  7. Nummela AT, Heath KA, Paavolainen LM, et al. Fatigue during a 5-km running time trial. Int J Sports Med. 2008;(29):738-745.
  8. Impellizzeri FM, Marcora SM, Castagna C, et al. Physiological and performance effects of generic versus specific aerobic training in soccer players. Int J Sports Med. 2006;(27):483-492.
  9. Buchheit M and Mendez-Villanueva A. Reliability and stability of anthropometric and performance measures in highly-trained young soccer players: effect of age and maturation. J Sports Sci. 2013;(31):1332-1343.
  10. Buchheit M and Mendez-Villaneuva A. Supramaximal intermittent running performance in relation to age and locomotor profile in highly-trained young soccer players. J Sports Sci. 2013;(31):1402-1411.
  11. Buchheit M, Kuitunen S, Voss SC, et al. Physiological strain associated with high-intensity hypoxic intervals in highly trained young runners. J Strength Cond Res. 2012;(26):94-105.
  12. Small K, McNaughton LR, Greig M, et al. Soccer fatigue, sprinting and hamstring injury risk. Int J Sports Med. 2009;(30):573-578.
  13. Boullosa DA and Tuimil JL. Postactivation potentiation in distance runners after two different field running protocols. J Strength Cond Res. 2009;(23):1560-1565.
  14. Mendez-Villanueva A, Buchheit M, Simpson BM, et al. Match play intensity distribution in youth soccer. Int J Sport Med. 2013;(34):101-110.
  15. Heaney N and Willey B. The efficacy of utilising the anaerobic speed reserve to prescribe supramaximal high intensity interval training with elite female hockey players. In Australian Strength & Conditioning Association Conference. Melbourne, 2013.
  16. Buchheit M. The 30-15 Intermittent Fitness Test: accuracy for individualizing interval training of young intermittent sport players. J Strength Cond Res. 2008;(22):365-374.
  17. Buchheit M. Should we be recommending repeated sprints to improve repeated-sprint performance? Sports Med. 2012;(42):169-172.
  18. Haugen T, Tonnessen E, Hisdal J, et al. The role and development of sprinting speed in soccer. Int J Sports Physiol Perform. 2013: Aug 27. [Epub ahead of print].
  19. Mendez-Villanueva A and Buchheit M. Football-specific fitness testing: adding value or confirming the evidence? J Sports Sci. 2013;(31):1503-1508.
  20. Hervert SR, Sinclair K, and Deakin GB. Does skill only conditioning help improve physiological and functional fitness in amateur soccer players? J Aust Strength Cond. 2013;(21):34-36.
  21. Dupont G, Blondel N, and Berthoin S. Performance for short intermittent runs: active recovery vs. passive recovery. Eur J Appl Physiol. 2003;(89):548-554.
  22. Mendez-Villanueva A, Buchheit M, Simpson B, et al. Does on-field sprinting performance in young soccer players depend on how fast they can run or how fast they do run? J Strength Cond Res. 2011;(25):2634-2638.
  23. Buchheit M, Simpson BM, and Mendez-Villaneuva A. Repeated high-speed activities during youth soccer games in relation to changes in maximal sprinting and aerobic speeds. Int J sport Med. 2012;(34):40-48.
  24. Rusko HK, Tikkanen HO, and Peltonen JE. Altitude and endurance training. J Sports Sci. 2004;(22):928-944; discussion 945.
  25. Billat LV, Slawinksi J, Bocquet V, et al. Very short (15s-15s) interval-training around the critical velocity allows middle-aged runners to maintain VO2 max for 14 minutes. Int J Sports Med. 2001;(22):201-208.
  26. Laughlin MH and Roseguini B. Mechanisms for exercise training-induced increases in skeletal muscle blood flow capacity: differences with interval sprint training versus aerobic endurance training. J Physiol Pharmacol. 2008;(59 Suppl 7):71-88.
  27. Astrand I, Astrand PO, Christensen EH, et al. Intermittent muscular work. Acta Physiol Scand. 1960;(48):448-453.
  28. Christensen EH, Hedman R, and Saltin B. Intermittent and continuous running. (A further contribution to the physiology of intermittent work.). Acta Physiol Scand. 1960;(50):269-286.
  29. Billat LV. Interval training for performance: a scientific and empirical practice. Special recommendations for middle- and long-distance running. Part I: aerobic interval training. Sports Med. . 2001;(1):13-31.
  30. Boullosa DA, Abreu L, Varela-Sanz A, et al. Do olympic athletes train as in the Paleolithic era? Sports Med. 2013;(43):909-917.
  31. Faude O, Schnittker R, Schulte-Zurhausen R, et al. High intensity interval training vs. high-volume running training during pre-season conditioning in high-level youth football: a cross-over trial. J Sports Sci. 2013;(31):1441-1450.
  32. Tuimil JL, Boullosa DA, Fernandez-del-Olmo MA, et al. Effect of equated continuous and interval running programs on endurance performance and jump capacity. J Strength Cond Res. 2011;(25):2205-2211.
  33. Stoggl T and Sperlich B. Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training. Front Physiol. 2014;(5):33.
  34. Bouchard C and Rankinen T. Individual differences in response to regular physical activity. Med Sci Sports Exerc. 2001;(33):S446-451.
  35. Baquet G, van Praagh E, and Berthoin S. Endurance training and aerobic fitness in young people. Sports Med. 2003;(33):1127-1143.
  36. Buchheit M. The 30-15 Intermittent Fitness Test : 10 year review. Myorobie Journal 2010;(1):http://www.martin-buchheit.net
  37. Bundle MW, Hoyt RW, and Weyand PG. High-speed running performance: a new approach to assessment and prediction. J Appl Physiol. 2003;(95):1955-1962.

Programming High-intensity Training in Handball

Based on the 2-part HIT review (I and II) on HIT programming with my mate Paul Laursen, I provide in this new paper some examples on how to practically implement HIT with players, and compare the performance benefits of different HIT formats in highly-trained Handball players. Many thanks to Aspetar Journal for the nice formatting too !

Pages from Buchheit - Programming High-intensity Training in Handball

 

Predicting changes in high-intensity intermittent running performance with acute responses to short jump rope workouts

Figures J Sport Sci & MedBuchheit M, Rabbani A and Taghi Beigi H. Predicting changes in high-intensity intermittent running performance with acute responses to short jump rope workouts in children. J Sport Sci & Med, 2014, In Press.

The aims of the present study were to 1) examine whether individual HR and RPE responses to a jump rope workout could be used to predict changes in high-intensity intermittent running performance in young athletes, and 2) examine the effect of using different methods to determine a smallest worthwhile change (SWC) on the interpretation of group-average and individual changes in the variables. Before and after an 8-week high-intensity training program, 13 children athletes (10.6±0.9 yr) performed a high-intensity running test (30-15 Intermittent Fitness Test, VIFT) and three jump rope workouts, where HR and RPE were collected. The SWC was defined as either 1/5th of the between-subjects standard deviation or the variable typical error (CV). After training, the large ≈9% improvement in VIFT was very likely, irrespective of the SWC. Standardized changes were greater for RPE (very likely-to-almost certain, ~30-60% changes, ~4-16 times > SWC) than for HR (likely-to-very likely, ~2-6% changes, ~1- 6 times >SWC) responses. Using the CV as the SWC lead to the smallest and greater changes for HR and RPE, respectively. The predictive value for individual performance changes tended to be better for HR (74-92%) than RPE (69%), and greater when using the CV as the SWC. The predictive value for no-performance change was low for both measures (<26%). Substantial decreases in HR and RPE responses to short jump rope workouts can predict substantial improvements in high-intensity running performance at the individual level. Using the CV of test measures as the SWC might be the better option.

Key words: submaximal heart rate; rate of perceived exertion; OMNI scale; 30-15 Intermittent Fitness Test; progressive statistics.

Moderate recovery unnecessary to sustain high stroke volume during interval training

IMG_20131125_081714Stanley J. & Buchheit M. Moderate recovery unnecessary to sustain high stroke volume during interval training, J Sport Sci & Med, 2014, In press.Recovery SV HIT

It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO2), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3 min work period, 2 min recovery) session on two occasions. VO2, HR and Qc were higher during moderate-intensity (60%) compared with low-intensity (30%) (VO2, effect size; ES=+2.6; HR, ES=+2.8; Qc, ES=+2.2) and passive (HR, ES=+2.2; Qc, ES=+1.7) recovery. By contrast, there were no clear differences in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES=−0.1; 30%, ES=−0.2). To conclude, moderate-intensity recovery may not be required to maintain a high SV during HIIT.

Keywords: high-intensity interval training; cardiac output; cardiac function; arteriovenous oxygen difference

JamieFollow Jamie on twitter

Changes of direction during high-intensity intermittent runs: neuromuscular and metabolic responses

Karim Hader, Alberto Mendez-Villanueva, Said Ahmaidi, Ben Williams and Martin
Buchheit. Changes of direction during high-intensity intermittent runs: neuromuscular and metabolic  responses. Accepted to BMC Sports Science, Medicine and Rehabilitation on 19 December 2013.

Abstract
Background: The ability to sustain brief high-intensity intermittent efforts (HIE) is meant to be a major attribute for performance in team sports. Adding changes of direction to HIE is believed to increase the specificity of training drills with respect to game demands. The aim of this study was to investigate the influence of 90°-changes of direction (COD) during HIE on metabolic and neuromuscular responses.
Methods: Eleven male, team sport players (30.5±3.6 y, 81±6 kg, 180± 6cm) performed randomly HIE without (straight-line, 2x[10x 22m]) or with (2x[10x ~16.5m]) two 90°-COD. To account for the time lost while changing direction, the distance for COD runs during HIE was individually adjusted using the ratio between straight-line and COD sprints. Players also performed 2 countermovement (CMJ) and 2 drop (DJ) jumps, during and post HIE. Pulmonary oxygen uptake ( O2), quadriceps and hamstring oxygenation, blood lactate concentration (Δ[La]b), electromyography amplitude (RMS) of eight lower limb muscles and rating of perceived exertion (RPE) were measured for each condition.
Results: During HIE, CODs had no substantial effects on changes in  O2, oxygenation, CMJ and DJ performance and RPE (all differences in the changes rated as unclear). Conversely, compared with straight-line runs, COD-runs were associated with a possibly higher Δ[La]b (+9.7±10.4%, with chances for greater/similar/lower values of 57/42/0%). There was also a lower decrease in lateral gastrocnemius (-8.5±9.3%, 1/21/78) and semitendinosus (-11.9 ± 14.6%, 2/13/85) electromyography amplitude; the decrease in electromyography amplitude for the other muscles was not clearly different.
Conclusion: Adding two 90°-CODs on adjusted distance during two sets of HIE is likely to elicit equivalent decreases in CMJ and DJ height, and similar cardiorespiratory and perceptual responses, despite a lower average running speed. A fatigue-induced modification in lower limb control observed with CODs may have elicited a selective reduction of electromyography activity in hamstring muscles and may induce, in turn, a potential mechanical loss of knee stability. Therefore, changing direction during HIE might be an effective training practice 1) to manipulate some components of the acute physiological load of HIE, 2) to promote long-term COD-specific neuromuscular adaptations aimed at improving performance and knee joint stability.
Key Words: cardiorespiratory responses; neuromuscular adjustment; selective activation; knee stabilization.

Full paper available on the Journal Website (open Access)

Supramaximal Training: repeated sprints vs. high-intensity running (individualized based on VIFT)

 

Med Sci Sports Exerc. 2008 Feb;40(2):362-71. doi: 10.1249/mss.0b013e31815aa2ee.

Supramaximal training and postexercise parasympathetic reactivation in adolescents.

Source

Research Laboratory, Physical Activity and Motor Control: Adaptation and Rehabilitation, Faculty of Sport Sciences, University of Picardie Jules Verne, Amiens, France. martin.buchheit@u-picardie.fr

Abstract

Repeated supramaximal exercise training is an efficient means of improving both aerobic and anaerobic energy system capacities. However, the influence of different levels of supramaximal training on parasympathetic function is unknown.

PURPOSE:

To compare the effects of repeated-sprint (RS) versus high-intensity intermittent training (HIT) on performance and postexercise parasympathetic reactivation in trained adolescents.

METHODS:

Fifteen male adolescents (15.6 +/- 0.8 yr) were divided into two groups that performed 9 wk of either RS (repeated all-out 6-s shuttle sprints; 14-20 s of recovery; N = 8) or HIT (15- to 20-s runs at 95% of the speed reached at the end of the 30-15 intermittent fitness test (V(IFT)); 15-20 s of recovery; N = 7). Groups performed intervals twice per week and maintained similar external training programs. Before and after training, performance was assessed by the V(IFT), countermovement jump (CMJ), 10-m sprint time (10 m), mean RS ability time (RSAmean), and heart rate (HRsub) level during a 6-min submaximal (60% V(IFT)) exercise test, where parasympathetic reactivation was assessed during the recovery phase (i.e., HR recovery time constant (HRRtau) and HR variability (HRV)).

RESULTS:

Parasympathetic function, V(IFT), and RSAmean were improved with HIT but not RS training. In contrast, changes in CMJ and HRsub were similar in both groups. A significant relationship was shown between the decrease in HRRtau and RSAmean (r = 0.62, P < 0.05; N = 15).

CONCLUSION:

HIT was more effective than RS training at improving postexercise parasympathetic function and physical performance. In addition, HRRtau, which was more sensitive to training than HRV indices, seems to be a useful performance-related measurement.