Monday, May 1, 2017

The Transition Period in Soccer: A Window of Opportunity

Below is a review paper we published last year with relevant points and practical advises. Should you are interested in learning more please click on the link here and send me an email. Limited copies will be provided. The infographic is by Dr Yann Le Meur.



 2016 Mar;46(3):305-13. doi: 10.1007/s40279-015-0419-3.
The Transition Period in Soccer: A Window of Opportunity.
Silva JRBrito JAkenhead RNassis GP
Abstract
The aim of this paper is to describe the physiological changes that occur during the transition period in soccer players. A secondary aim is to address the issue of utilizing the transition period to lay the foundation for the succeeding season. We reviewed published peer-reviewed studies if they met the following three selection criteria: (1) the studied population comprised adult soccer players (aged >18 years), (2) time points of physiological and performance assessments were provided, and (3) appropriate statistics for the calculation of effect sizes were reported. Following two selection phases, 12 scientific publications were considered, involving a total sample of 252 players. The transition period elicits small to moderate negative changes in body composition, a moderate decline in sprint performance with and without changes of direction, and small to moderate decrements in muscle power. Detraining effects are also evident for endurance-related physiological and performance outcomes: large decrements in maximal oxygen consumption V̇O2max) and time to exhaustion, and moderate to very large impairments have been observed in intermittent-running performance. Off-season programs should be characterized by clear training objectives, a low frequency of training sessions, and simple training tools in order to facilitate compliance. The program suggested here may constitute the 'minimum effective dose' to maintain or at least attenuate the decay of endurance- and neuromuscular-related performance parameters, as well as restore an adequate strength profile (reduce muscle strength imbalances). This periodization strategy may improve the ability of players to cope with the elevated training demands of pre-season training and therefore reduce the risk of injury. Moreover, this strategy will favor a more efficient development of other relevant facets of performance during the pre-competition phase (e.g., tactical organization). We contend that the transition period needs to be perceived as a 'window of opportunity' for players to both recover and 'rebuild' for the following season.

Friday, April 21, 2017

Injury prevention training in football: Time to consider training under fatigue?

dailystar.co.uk

 by Darren Paul, Joao Brito, George Nassis

Muscle injuries often occur towards the end of each half and this has been associated with fatigue (1). Current practice often means injury prevention training is performed at the start of the session. The hypothesis is that when training is performed in a fresh state it allows players to demonstrate better form. In this article we will look at fatigue, fitness and training order to question this existing practice and build a case for performing injury prevention at the end of practice, when in a fatigued state.

DEMANDS OF FOOTBALL
Football is a sport where players perform bouts of high intensity activity interspersed with periods of lower intensity. The demands are increased by having to execute complex movements such as accelerating and decelerating, changing direction, jumping and tackling, parts of which are likely to impact on the characteristics of the match (2). To do this players need an appropriate level of fitness, namely moderate-to-high aerobic and anaerobic power, good agility, flexibility and muscular development and the ability to generate power during fast movements. Although players may not excel across all of the physical components, they should possess levels that will allow them to remain competitive for the whole match.

It is clear that physical qualities are not the only determinant of match performance. The outcome of a match depends on the complex interaction of several physical, psychological, technical and tactical factors. The work rate of a player in a match is also dependent on many other factors. Some of these are:
  • the quality of the opposition,
  • changes in positional role,
  • the effects of previous and/or forthcoming game commitments,
  • environmental conditions,
  • dehydration,
  • cultural differences and other intrinsic and extrinsic factors.

One example of the complexities is the distance covered. In the English Premier League players from less successful teams cover significantly greater distances in high-intensity activities than their more successful counterparts(3). The opposite was found in Italy where players of the most successful teams from the Italian Serie A perform more high-intensity activities during a game when in possession of the ball compared with players of less successful teams(4). It is improper to suggest that superior fitness and/or players'/teams' levels will manifest in higher amounts of effort during any given match.

FATIGUE
Given the demanding nature of football, players will likely experience a degree of transient or accumulated fatigue at some stage of the match. The oversimplification of interpreting this with time-motion analysis is that players tend to experience this fatigue or/and impaired performance mainly after short-term, intense periods in both halves and towards the end of the match(5). However, basing assumptions regarding physical fitness and fatigue purely on activity profile statistics is flawed; particularly given that our understanding of physiological responses during match activity remains limited. For example, it is still unknown to what extent the dynamic responses to match demands (such as accumulation of metabolites in muscles, plasma osmolality, substrate availability, body temperature and dehydration) prevent total breakdown of any single peripheral physiological system, either prematurely or in the final periods of the match(6).

Fatigue has become a hot topic in football despite being regarded as a complex and multi-factorial entity. There is growing interest as to how fatigue relates to recovery, player fitness and effort during matches. To avoid exhausting themselves before the final whistle, players are likely to adopt a pacing strategy that allows them to be involved in demanding and critical moments, even during the final stages of a match. The regulation of self-chosen high intensity activity is also an important product of training, as players need to learn to adopt pacing strategies that will allow a high effort even during the final stages, or when required. For example, an early sending off might increase the overall work rate of outfield players. Hence, there is likely a demand to cover more distance in order to counteract the numerical disadvantage. This may result in higher levels of fatigue towards the end of the game(6). The large match-to-match variability of individual player work rates, particularly high intensity activity, as a representation of time-motion analysis means players are unlikely to perform to their maximal capacity during most matches.



FITNESS
When planning training sessions, coaches should take into account that playing and training affect each individual player differently. One of the objectives of a fitness test battery is to identify differences in players' physical characteristics. A variety of fitness tests are currently used to monitor performance and evaluate training response. Unfortunately, there is no exact measure for ‘physical performance’ in a football match. This stresses the fact that individual performance in fitness tests should not be used to directly predict performance in competition. Nonetheless, player fitness should be considered as a factor that contributes to match result. This means that using fitness tests together with physiological data might be useful for monitoring performance measure changes and directing training prescription. If testing and/or monitoring are not done often, coaches might not detect adaptations, which can occur faster than the time between tests. From an applied perspective, this remains a challenge, as coaches are sometimes reluctant to sanction frequent testing within the season. This is despite the fact that routine monitoring may aid periodisation strategies, prevent under/overtraining and maintain players in optimal condition.

A relevant question when planning training sessions relates to fatigue. This is important as muscle injuries (e.g. hamstring strains, the most prevalent muscle injuries in football) typically occur in the latter stages of a match(7). Interestingly, fatigue during the match has been associated with decreased eccentric strength and flexibility(7). Most joint sprains also occur towards the final stages of each half of the match. We think that this might be associated with fatigue-related changes in neuromuscular control, joint dynamic stability, and postural control. This may result in players performing ‘different’ movement patterns than when they are fresh. Fatigue may lead to players using potentially injurious landing and turning techniques that occur during the later stages of football activity. Evidence to support this theory was seen using a 90-minute intermittent exercise protocol, representative of football match play. During the protocol, players had time-dependent impairments in sprinting kinematics, peak eccentric hamstring torque, functional strength ratio and overall sprint performance during the latter stages of the test(7). Such research supports our hypothesis that fatigue is a major injury risk factor of match play.

Low fitness level is thought to be an injury risk factor for players(3). Therefore, practitioners often try to elevate physical fitness in the belief that this will reduce the incidence of fatigue and accompanying injury. It cannot be overlooked, however, that players with greater physical fitness will simply work at a greater, rather than reduced, relative intensity, the implication being players may still suffer from fatigue. Players tend to perform less physical work and fewer skilled actions in the second half of a match compared to the first, regardless of ability. However, given that players may rarely perform to the maximum capacity in a match, the relationship between maximal (test) performance, fitness and injury occurrence is far from simple. This is likely to have profound implications for conditioning as part of the training programme. Despite such knowledge, there appear to be few time-related guidelines on when to embed injury prevention training into the practice sessions.

Resistance to fatigue is a key factor for a player to continually perform throughout the whole match. Indeed, the player’s performance in response to training can be estimated from the balance between a negative (fatigue) and positive function (fitness). There is a fine line between improving fitness and negatively overloading the player, which could cause injury. There is now growing emphasis placed on monitoring training loads (using global positioning systems, heart rate monitors, time-motion analysis and subjective scales such as rate of perceived exertion) to allow teams to better manage and monitor training loads. Such tools are commonly used within the applied setting and are deemed important to develop performance-enhancing training guidelines.

TRAINING ORDER
The issue of training order is considered an important factor in the design of training programmes. Generally, this con-cept has been considered with regards to the order of endurance and strength training and a possible interference effect(8). Either order of training has its advantages and disadvantages. This means it is important to consider the objective of the training session. For example, residual fatigue from the endurance component of concurrent training may compromise the ability to develop tension during the strength element of concurrent training. Essentially, there appears a likely trade-off that needs to be considered in view of the training goal.

SPECIFICITY
The law of training specificity states that the specific nature of a training load produces its own specific response and adaptations(9). By inference, it would seem training in a fatigued state may improve performance in a fatigued state, too. In terms of injury prevention training, it seems the general approach is to perform drills earlier at the start of the session, often in a non-fatigued state. The justification is that players perform efforts in a ‘fresh condition’ that allows the musculature to produce the appropriate responses of protective function in maintaining stability, balance and body control. We propose some injury prevention training would be effective when performed after rather than before fatigue sets in. The reality of the match means that players will execute specific tasks in both non-fatigued and fatigued conditions. Hence, it would seem training in both conditions might benefit the players.

Research has started to examine the effect of injury prevention training under fatigued conditions. The limited number of studies available have mainly been conducted in semi-professional football players and more studies in professional players are needed. In one study, eccentric strength training conducted post-training was shown to significantly reduce the negative influence of fatigue on hamstring strength(9). Following the 8-week intervention, players who performed the training fatigued, compared to non-fatigued, showed better maintenance of eccentric hamstring strength and preserved functional eccentric hamstring to concentric quadriceps stre-ngth ratio during an intermittent test. A real life significant reduction in match-play hamstring injury rate in Australian Rules football was shown following an intervention strategy, including a football-specific eccentric hamstring strength drill, performed in a fatigued state(10). The protective qualities may apply to other intrinsic factors that can be trained. For instance, a greater improvement in balance ability was observed when balance training was performed after, rather than before, football training(11). This means that training in a fatigued state could also be applied to proprioception. Intuitively, the application of this as a training strategy is largely dependent on the trainers’ objective within the session. However, we recommend that the timing for injury prevention training, including eccentric strength training, core stability, neuromuscular control and balance drills, should vary between training sessions as a strategy to improve adaptability to the specific demands of the game.



CONCLUSION
In conclusion, we recommend practitioners consider performing injury prevention training in a fatigued state too. By exposing the player to training under fatigue, we can better prepare them for the demands of the match. This strategy might assist in reducing the match fatigue-related injuries.
 Published in Aspetar Sp Med Journal


References
1.         Ekstrand J, Hägglund M, Waldén M. Epidemiology of muscle injuries in professional football (soccer). Am J Sports Med 2011; 39:1226-32.
2.        Mohr M, Krustrup P, Bangsbo J. Match performance of high standard soccer players with special reference to development of fatigue. J Sports Sci 2003; 21:519-28.
3.        Rampinini E, Impellizzeri FM, Castagna C, Coutts AJ, Wisloff U. Technical performance during soccer matches of the Italian Serie A league: effect of fatigue and competitive level. J Sci Med Sport 2009; 12: 227-233.
4.        Dvorak J, Junge A, Chomiak J, Graf-Baumann T, Peterson L, Rösch D et al. Risk factor analysis for injuries in football players.  Possibilities for a prevention program. Am J Sports Med 2000; 28:S69-74.
5.        Di Salvo V, Gregson W, Atkinson G, Tordoff P, Drust B. Analysis of high intensity activity in Premier League soccer. Int J Sports Med 2009; 30:205-212.
6.       Mohr M, Krustrup P, Bangsbo J. Fatigue in soccer: a brief review. J Sports Sci 2005; 23: 593-599.
7.        Small K, McNaughton LR, Greig M, Lohkamp, Lovell R. Soccer fatigue, sprinting and hamstring injury risk. Int J Sports Med 2009; 30:573-578.
8.        Rønnestad BR, Hansen EA, Raastad T. High volume of endurance training impairs adaptations to 12 weeks of strength training in well trained endurance athletes. Eur J Appl Physiol 2012; 112:1457-1466.
9.       Small K, McNaughton L, Greig M, Lovell R. Effect of timing of eccentric hamstring strengthening exercises during soccer training: implications for muscle fatigability. J Strength Cond Res 2009; 23:1077-1083.
10.     Verrall GM, Slavotinek JP, Barnes PG The effect of sports specific training on reducing the incidence of hamstring injuries in professional Australian Rules football players. Br J Sports Med 2005; 39:363-368.
11.       Gioftsidou A, Malliou P, Pafis G, Beneka A, Godolias G, Maganaris CN. The effects of soccer training and timing of balance training on balance ability. Eur J Appl Physiol 2006; 96:659-664.

Wednesday, April 19, 2017

What are the barriers to effective implementation of injury prevention practices in high level football?

Graph 1

In the survey of workload practices of high level football clubs (Akenhead & Nassis), 41 sport scientists and fitness coaches responded to specific questions. There were two questions relevant to this post’s title; one asked the participants to rate their perceived expected and actual effectiveness of their strategy on injury prevention and performance enhancement. The other one asked them to name and rate the barriers to workload monitoring effectiveness on injury prevention and performance improvement. Their answers, as means and SD, appear in these 2 graphs.

Briefly, here is the summary of the answers:
-Actual effectiveness of workload monitoring was rated as being lower that the expected effectiveness for injury prevention and performance improvement (Graph 1)
-The main barriers to effective implementation of the workload practices were insufficient manpower and low coach buy-in.



Graph 2




What can we do?
Use more effective communication strategies to enhance integration with coaching staff.


For full access of the original study please visit this website and send email request to  georgenassis@gmail.com (limited copies will be provided).

Wednesday, April 5, 2017

Workload monitoring in football (soccer): what do high level teams do?

We have surveyed the practices of high level football clubs in terms of workload monitoring tools and approaches they use. Questionnaires from 41 teams were collected: 16 English Premier League, 7 Major League Soccer (USA), 7 English Championship, 4 Ligue Un, 2 teams from the Scottish Premier League and 1 team from each of Serie A, La Liga, Dutch Eredivisie, Australian A League and the Swiss Super League. These graphs present the main findings.


Those who want to read the study please click here. Should you wish a free copy please email (the first 30 will receive a pdf of the study).

Monday, April 3, 2017

Can genetic testing identify if your child is a talented athlete?

for source see below

In recent years we have experienced the rise of an emerging market of direct-to-consumer* genetic testing that claims to be able to identify talented children who have the potential to become elite athletes. Applying good marketing these claims target the parents and the coaches. What is the truth? Do genetic tests help in talent identification?

A panel of world class experts evaluated the published literature and wrote a consensus paper which I believe should serve as the guideline document until further knowledge is developed. Below are the main points and concerns of the experts on the role of genetic testing in talent identification. As the experts claim:
- There is concern among the scientific community that the current level of knowledge is being misrepresented for commercial purposes
-“There is concern over the lack of clarity of information over which specific genes or variants are being tested and the almost universal lack of appropriate genetic counselling for the interpretation of the genetic data to consumers

The experts’ conclusion is that … in the current state of knowledge, no child or young athlete should be exposed to direct-to-consumer genetic testing to define or alter training or for talent identification aimed at selecting gifted children or adolescents.”

To add on that piece of information, excellence in sports is not solely determined by genes. No doubt that one needs an appropriate genetic background which together with well planned, dedicated training, athlete’s willingness to excel and the family/social support may lead to high performance.

Those with more interest in the area can access the consensus paper from the British Journal of Sports Medicine for free here




*Direct-to-consumer (DTC) genetic testing refers to testing sold directly to consumers via the television, internet or other marketing venues without the involvement of  health care professionals.

Sources

Wednesday, March 29, 2017

What are the key leadership skills required by sports professionals? lessons from Sir Alex Ferguson

Coaching a team or leading a sports science and medicine team requires leadership skills. People have different perceptions on which is the most effective approach to achieve top performance. Better to learn from the top leaders. 

Sir Alex Ferguson is one of them and in this video he is sharing his thoughts and practices. It is worth watching clicking here  

Improve players' aerobic capacity to protect them from injuries



The general consensus up to date is that rapid changes in workload are associated with higher risk of muscle injuries. To monitor the workload trends, practitioners now employ the acute (last week) to chronic (last 4 weeks) workload ratio.

It seems, although the data are limited, that a ratio between 1 and 1.25 is protective to injuries in professional soccer players. The question is: does this range of values apply to every player?

In a 2016 study, 48 professional soccer players belonging to 2 elite European teams were followed for one season. Weekly workload was monitored and the muscle injuries were recorded. Aerobic capacity was assessed with the Yo-YoIR1. Their results showed that players with high aerobic capacity presented lower risk of injury despite the rapid changes in weekly workload compared to players with lower aerobic fitness. 

Therefore, one of the training objectives should be to improve aerobic capacity. I believe these findings apply to all levels of team sports athletes and to most age categories, respecting the windows of training opportunities. 

Take home message
Players with high aerobic capacity are able to tolerate the rapid changes in workload better compared to players with lower aerobic capacity.


Source
Malone et al (2016). J Sci Med Sport [Nov 9 ahead of print]


Wednesday, March 15, 2017

What have we learned from UEFA Champions League so far?

uefa.com
We are reaching the end of the round of 16, with 2 matches missing tonight, and here I have summarized lessons to be learned so far.

Lesson 1: Don’t always trust the numbers: From a data analysis perceptive Sevilla FC could have won the match yesterday. Compared to Leicester City FC, they had more ball possession (68% vs 32%), more passes completed (531 vs 199!), higher passes accuracy (86% vs 70%) and more attempts on target (5 vs 4). In addition, Sevilla players covered greater distance running compared to Leicester (106.2 km vs 104.4 km). Though, Sevilla lost the match! Last week, PSG players covered much greater distance in the field (110.4 km vs 105.8 Km) though they were defeated by FC Barcelona. Match winning is so complex and affected by not only technical and physical elements but also other factors like players’ desire to win (!), robustness of the team, fans’ support.

uefa.com



So, what’s going on? Are the data we collect (huge amounts indeed) useless? No, this is not the case. Data are needed and will assist in making more intelligent solutions. It’s not about the data; It’s about how you interpret the numbers. Smart data interpretation require the ability to read the context!

Bottom line; numbers have a meaning when someone attempts to interpret them looking at the context. In one of our papers we have addressed the issue of critical thinking in football performance and I suggest you have a look should you are more interested in this area. Here is the link https://www.researchgate.net/publication/273071207_Factors_Affecting_Match_Running_Performance_of_Elite_Soccer_Players_Shedding_Some_Light_on_the_Complexity?ev=prf_pub


Lesson 2: Smart planning leads to success. Leicester are not doing well in the English Premier League but they are very successful in the Champions League. I assume the Club has made a decision right from this season’s beginning and prioritized the objectives based on the team’s strengths and weaknesses.

Lesson 3: Smart support may raise the team to a higher level. I am sure you all agree Leicester FC have been a successful example of smart planning and decision making at all levels. Science and medical staff play a role in this success story. Proper training and recovery periodization and injury prevention strategies are key action plans that can add value and boost the team's performance to a higher level.

To learn more about how this is happening in Leicester City FC I advise you to watch the video with the Head of Sports Science speaking https://www.youtube.com/watch?v=_7Rsdj-_AoI&feature=youtu.be&list=PL8z05aMc--mi4LZb2wynvSYUqlR1ou20

To learn more on how intelligent approaches may help the team to achieve more, you can have a look at resources below

-effective recovery strategies https://www.ncbi.nlm.nih.gov/pubmed/23315753







Friday, February 17, 2017

高温环境中训练和比赛的共识性建议 (Consensus Recommendations on Training and Competing in the Heat)




source:johnsonfitness

Our paper published in Chinese (Clin J Sports Med 2016) FREE to download from the link below
http://cbimg.cnki.net/Editor/2016/0309/ydyx/8e8c1979-3de0-4c98-8bb5-6784610f8c60.pdf

Consensus Recommendations on Training and Competing in the Heat
Original Authors:Sébastien Racinais,Juan-Manuel Alonso,Aaron J. Coutts,Andreas D. Flouris,Olivier Girard,José González -Alonso,Christophe Hausswirth,Ollie Jay,Jason K. W. Lee,Nigel Mitchell,George P. Nassis,Lars Nybo,Babette M. Pluim,Bart Roelands,Michael N. Sawka,Jonathan Wingo,Julien D. Périard.

For those who don't speak Chinese, the English version is FREE to download here https://www.researchgate.net/publication/278327658_Consensus_recommendations_on_training_and_competing_in_the_heat

Monday, February 13, 2017

Competencies required by effective strength & conditioning coaches

http://articles.mcall.com/2014-01-06/sports/mc-penn-state-football-coach-0106-20140106_1_miami-coach-al-golden-strength-coach-vanderbilt-coach-james-franklin

Effective strength and conditioning coaching is a complex series of actions that require competencies across a wide range of areas. The below article by Dr, Ian Jeffreys explores our understanding of effective coaching using Gardner's Five minds.

The article can been found here

Enjoy reading!
Warm regards
George

Saturday, February 11, 2017

Vacancy in High Performance-Human Performance Specialist, Williams F1



Human Performance Specialist
Williams F1

More information about this job: 

Overview:

We are currently seeking a Human Performance Specialist to join our Race Team on a full time basis. Reporting to the Head of Health and Human Performance, and the Sporting Manager when travelling, the successful candidate will be responsible for maintaining and developing the current physical performance programme for the Williams Race Team. The role also requires an element of psychological coaching in order to ensure individual performance in high pressure environments. With support from the Health and Human Performance team at the factory, the successful candidate will facilitate a data-informed approach to fitness training and performance analysis therefore experience with biometrics or similar statistical analysis is preferred. 
More information here


Monday, October 31, 2016

Outsiders’ intelligence: Time to re-think current practices?










“If nothing is going right, turn left”
Anonymous


We live in an era of accelerated knowledge. In modern elite level sports and in particular in football, input from the backroom staff (medicine and science practitioners) is considerable and influences the coaches’ decision-making process. However, it appears that there is a huge gap between knowledge gained in the lab or via research and actual benefit for the team in the field. As an example, injuries incidence in elite football players remained unchanged over the last 10 years. This was despite the growing number of scientific papers on prevention over the same period and the fact that some clubs are using injury prevention programs regularly. Another example, again in elite football, is related to the effect of congested fixture on performance. As most of you know, congested fixture will possibly result in performance decrements despite the fact that training and recovery methods have been substantially improved over the last years. Are we heading in the right direction? Should we start thinking differently?

Why injuries incidence remains stable?
With reference to the first example above, a number of reasons may explain the relatively low effectiveness of injury prevention programs on the injury incidence in elite football. Some of these factors are: the lack of applied research which is real-life questions driven, the inability to translate current research into effective practice, the relatively low players’ compliance with the prevention training. If player’s commitment with the specific exercise program is an issue (as some researchers and practitioners suggest) we should concentrate more on understanding our players rather than on developing exercise drills. Knowledge from social sciences might help in understanding our players better. In extension to that, it is assumed that the lack of fresh ideas and of the 360o view might also be a factor. As in other expertise knowledge from other areas, outsiders’ knowledge, could add value and help in finding solutions to current challenges.

What can we learn from the outsiders?
In terms of injury prevention and risk detection approaches in elite footballers, the majority of strategies so far are fragmented. Screening tests, mostly performed at the start of season and in isolation to the game context, are correlated with the injury incidence throughout the season. However, to link any injury with its risk factors we should at least analyze the specific movement and the context (e.g. time of match, style of play) that it occurs. For that reason, we must integrate measures and data from movement and performance analysis, energy system function, psychological status and previous training principles. This requires a dynamic and holistic approach in data analysis. Several business units of a dynamic nature use approaches to deal with big data and reach meaningful conclusions, being, for instance, the risk of taking a decision, prices/budget forecasts, consumers behavior etc. I am sure that modern sports have to learn a lot from these practices.
USA navy wanted to use the most advanced tools to screen their pilots’ ability to perform well under high psychological stress. This initiative was driven by the strategic objective to reduce the human lives losses and financial cost in case of fatal events. Their research showed that certain proteins are valid candidate molecules to identify individuals who can perform well while under high stress. I am not claiming that we should use exactly the same genomic approach as in pilots but this knowledge from outsiders might help us to improve the tools we use in football.

Football can learn from top business
Business owners in the City of London wanted to know which biological factors affect the traders’ decision making. If they are able to identify the influential biological markers next step would be to manipulate them towards the optimal level. Saliva samples were collected from the traders every morning and were analyzed for testosterone and cortisol concentration. The saliva hormones daily variations were plotted against their performance (money profit and losses). The results showed that the traders were making profits in the days that testosterone concentration was high. This is particularly relevant to elite sports where all actions should align to optimize performance at a certain time of day.

What’s next?
To my view we should rethink the way we approach, plan and execute science in modern sports. To provide effective solutions to coaches/managers, being tools to injury incidence reduction and performance enhancement, we should also look at other areas and places. Knowledge from outsiders might help.



George Nassis holds a doctorate degree in exercise physiology & sports science and has long experience as a physiologist and head of performance in football. He has extensive experience on the integration of sports medicine and science for injury prevention and performance enhancement. George has published more than 50 papers in peer-reviewed scientific journals (h-index=18). 

Monday, July 20, 2015

Does regular post-exercise cold application attenuate training adaptations?

That's a fundamental questions asked by many coaches and practitioners over the last year(s) (http://georgenassis.blogspot.gr/2011/07/some-thoughts-on-use-of-water-immersion.html). This concern is growing as more data is published showing that regular cold application might attenuate training adaptations.


What's new?
Yamane and colleagues (2015) asked their participants to train with wrist flexion exercises, 3 times a week for 6 weeks. Seven subjects immersed their forearms in cold water (10 ± 1°C) for 20 min after each training whereas the other 7 didn't immerse their limbs. Their results showed that regular post-exercise cold application attenuated muscular and vascular adaptations to this type of training (http://www.ncbi.nlm.nih.gov/pubmed/25760154).

In a more recent study, 21 active males participated in a strength training program for 12 weeks. Post-exercise recovery included either 10-min cold water immersion (CWI) or active recovery. Their results showed that CWI attenuates the exercise training induced hypertrophy (http://www.ncbi.nlm.nih.gov/pubmed/26174323).

Points to consider
Although both studies provide novel data on the potential role of regular post-exercise cold water immersion on training adaptations, they are not without limitations. Their main limitation is that participants were non-trained and, thus, we don't know if these results apply to trained individuals.

Evidence against 
On the other side, Ihsan et al. (2015) recently showed that regular cold water immersion following endurance training sessions may enhance mitochondrial biogenesis (http://www.ncbi.nlm.nih.gov/pubmed/26041108). As in the above mentioned studies, non-trained subjects were recruited and this limits the applications of these findings.


Take-home message
My opinion is that there is evidence that regular post-exercise cold application attenuates adaptations to training. We should acknowledge however that this information comes from non-trained males following strength training. Until more data in trained and possibly elite individuals are published we should be more concerned with the regular application of cold as a means of recovery.

Friday, July 10, 2015

Training load assessment in elite football players: should we trust what we read?

with Djibril Cisse  (Pre-season camp in Austria, July 2010)

As most of you know, training load (TL) assessment is vital to injury prevention strategy development. There are various tools of TL assessment, with the Rate of Perceived Exertion being one of the most popular. 

In one of our papers (Brito, Hertzog, Nassis 2015), accepted for publication last week, we analysed the TL of highly trained football players daily throughout the entire season. The fatigue index was assessed once per week for the same period. 

Our main finding was that training load was affected by a number of factors like previous and next match result and location. In addition, although TL fluctuated throughout the year the fatigue index remains relatively stable. Given the limitations of our methodology, we speculate that highly-trained players choose their pace during training in order to avoid excess fatigue throughout the season.

Practical implications

1) RPE-based training load assessment may not be as accurate as we think, and 
2) highly-trained players have the ability to modify their pace in order to avoid excessive fatigue. Although this speculation remains to be proved with more robust experimental designs, our data suggest we should consider modifying our strategies on fatigue & injury prevention.

The abstract of this study can be reached at 

Friday, June 12, 2015

Post-exercise recovery: time to reconsider our practice?

sports.ndtv.com

Following the last week's post (here http://georgenassis.blogspot.com/2015/06/cold-water-immersion-is-it-all-in-our.html), I have received a number of emails with valid comments. Thank you all for that!

It is evident that post-exercises strategy is a "hot" topic in sports. There is substantial literature on that topic. Does this knowledge makes a big difference in the field? 

Based on my experience, there is need for more work on the applicability of the post-recovery strategies in a real life set-up. For instance, players' compliance to some recovery methods is variable, if not low, at some periods. This is of course a fact that affects the methods' effectiveness.

In a previous post, I highlight the findings of a study that examined player's perception on recovery methods and the effectiveness of these methods on recovery (here http://georgenassis.blogspot.com/2012/07/which-is-most-effective-recovery-method.html).

To summarize my thoughts, I believe that:
  • we need to implement a more holistic approach by applying various methods depending on the athlete's belief and the period of the year
  • we must improve players buy-in. If athletes believe on the method, they will comply and this might result in better recovery.


Again, your contribution is very much appreciated.

Regards
George

Friday, June 5, 2015

Cold water immersion for recovery: is it all in our mind?

greekamericannewsagency.com


Cold water immersion is a very popular strategy for recovery after exercise. Although there is evidence on its benefits on perception of fatigue no consensus exists on its effect on performance. In addition, many studies show no effect of this strategy on physiological functions. Part of the confusion might be due to the studies' design. Indeed, most studies have not used a placebo condition and this could have affected the conclusion and hence the practical applications.

The study of Broatch et al (2014) investigated if the placebo effect is responsible for any acute performance and psychological benefit of postexercise cold water immersion. Following a high-intensity interval session, the participants followed one of the 3 following recovery conditions i) cold water immersion at 10 oC, ii) thermoneutral water immersion placebo (34.7 oC), iii) thermoneutral water immersion control (34.7 oC). 

Their conclusion was that a recovery placebo administered after high-intensity exercise was as effective as cold water immersion in the recovery of muscle strength over 48 hours. In addition, both the cold water and the thermoneutral immersion placebo resulted in faster recovery of strength compared with the control condition.

This study shows that at least part of any benefit of cold water immersion is due to a placebo effect.


How this study might affect practice?

  • Postexercise water immersion even at around 30 oC may produce similar performance improvements compared to cold water immersion provided we lead athletes believe that thermoneutral water immersion is beneficial on performance recovery.
  • Medical & sports science staff should not be so concerned about the water temperature itself. 
  • Thermoneutral water immersion is more comfortable to athletes and this should be taken into consideration when planning a recovery strategy.


Some concerns

  • This study examined the recovery of muscle strength. We don't know what might happen with the application of the same recovery strategy on other performance parameters such as speed, repeated sprints ability and endurance.


Source
Broatch et al (2014). Med Sci Sports Exerc, 46(11):2139-47.


Friday, May 15, 2015

Training or competing in the heat: how to protect your health & boost performance?

healthline.com
In the below article you can find the most recent update on recommendations for event organizers, athletes, coaches and scientists. You can download free from the Scandinavian Journal of Medicine & Science in Sports at
http://onlinelibrary.wiley.com/doi/10.1111/sms.12467/epdf

Friday, April 24, 2015

Altitude & performance: what's new?

 2015 Feb 9. [Epub ahead of print]

"Live High-Train Low and High" Hypoxic Training Improves Team-Sport Performance.

Abstract

PURPOSE:

To investigate physical performance and hematological changes in 32 elite male team-sport players after 14 days of 'live high-train low' (LHTL) in normobaric hypoxia (≥14 h.day at 2800-3000 m) combined with repeated-sprint training (6 sessions of 4 sets of 5 x 5-s sprints with 25 s of passive recovery) either in normobaric hypoxia at 3000 m (LHTL+RSH, namely LHTLH; n = 11) or in normoxia (LHTL+RSN, namely LHTL; n = 12) compared to controlled 'live low-train low' (LLTL; n = 9).

METHODS:

Prior to (Pre-), immediately (Post-1) and 3 weeks (Post-2) after the intervention, hemoglobin mass (Hbmass) was measured in duplicate (optimized carbon monoxide rebreathing method) and vertical jump, repeated-sprint (8 x 20 m - 20 s recovery) and Yo-Yo Intermittent Recovery level 2 (YYIR2) performances were tested.

RESULTS:

Both hypoxic groups increased similarly Hbmass at Post-1 and Post-2 in reference to Pre- (LHTLH: +4.0%, P<0.001 and +2.7%, P<0.01; LHTL: +3.0% and +3.0%, both P<0.001), while no change occurred in LLTL. Compared to Pre-, YYIR2 performance increased by ∼21% at Post-1 (P<0.01) and by ∼45% at Post-2 (P<0.001) with no difference between the two intervention groups (vs. no change in LLTL). From Pre- to Post-1 cumulated sprint time decreased in LHTLH (-3.6%, P<0.001) and in LHTL (-1.9%, P<0.01), but not in LLTL (-0.7%), and remained significantly reduced at Post-2 (-3.5% P<0.001) in LHTLH only. Vertical jump performance did not change.

CONCLUSION:

'Live high-train low and high' hypoxic training interspersed with repeated sprints in hypoxia for 14 days (in-season) increases Hbmass, YYIR2 performance and repeated-sprint ability of elite field team-sport players with the benefits lasting for at least three weeks post-intervention.


 2015 Jan 26. [Epub ahead of print]

Altitude Training in Elite Swimmers for Sea Level Performance (Altitude Project).


INTRODUCTION:

This controlled nonrandomized parallel groups trial investigated the effects on performance, V˙o2 and hemoglobin mass (tHbmass) of 4 preparatory in-season training interventions: living and training at moderate altitude for 3 and 4 weeks (Hi-Hi3, Hi-Hi), living high and training high and low (Hi-HiLo, 4 weeks), and living and training at sea level (SL) (Lo-Lo, 4 weeks).

METHODS:

From 61 elite swimmers, 54 met all inclusion criteria and completed time trials over 50 and 400 m crawl (TT50, TT400), and 100 (sprinters) or 200 m (non-sprinters) at best stroke (TT100/TT200). V˙o2max and heart rate were measured with an incremental 4x200-m test. Training load was estimated using TRIMPc and session RPE. Initial measures (PRE) were repeated immediately (POST) and once weekly on return to SL (PostW1 to PostW4). tHbmass was measured in duplicate at PRE and once weekly during the camp with CO rebreathing. Effects were analyzed using mixed linear modeling.

RESULTS:

TT100 or TT200 was worse or unchanged immediately POST, but improved by ∼3.5% regardless of living or training at SL or altitude following at least 1 week of sea level recovery. Hi-HiLo achieved a greater improvement two (5.3%) and four weeks (6.3%) after the camp. Hi-HiLo also improved more in TT400 and TT50 two (4.2% and 5.2%, respectively) and four weeks (4.7% and 5.5%) from return. This performance improvement was not linked linearly to changes in V˙o2max or tHbmass.

CONCLUSION:

A well- implemented 3- or 4-week training camp may impair performance immediately, but clearly improves performance even in elite swimmers after a period of SL recovery. Hi-HiLo for 4 weeks improves performance in swimming above and beyond altitude and SL controls, through complex mechanisms involving altitude living and SL training effects.


 2015 Feb 24. [Epub ahead of print]

Effects of Altitude on Performance of Elite Track-and-Field Athletes.

Abstract

PURPOSE:

Lower barometric pressure of air at altitude can affect competitive performance of athletes in some sports. Here we report the effects of various altitudes on elite track-and-field athlete's performance.

METHODS:

Lifetime track-and-field performances of athletes placed in the top 16 in at least one major international competition between 2000 and 2009 were downloaded from the database at tilastopaja.org. There were 132,104 performances of 1889 athletes at 794 venues. Performances were log-transformed and analyzed using a mixed linear model with fixed effects for 6 levels of altitude and random quadratic effects to adjust for athlete's age.

RESULTS:

Men's and women's sprint events (100-400 m) showed marginal improvements of ~0.2% at altitudes of 500-999 m, and above 1500 m all but the 100-and 110-m hurdles showed substantial improvements of 0.3-0.7%. Some middle- and long-distance events (800-10,000 m) showed marginal impairments at altitudes above 150 m, but above 1000 m the impairments increased dramatically to ~2-4% for events >800 m. There was no consistent trend in the effects of altitude on field events up to 1000 m; above 1000 m hammer throw showed a marginal improvement of ~1%, and discus was impaired by 1-2%. Above 1500 m, triple jump and long jump showed marginal improvements of ~1%.

CONCLUSIONS:

In middle-and long-distance runners altitudes as low as 150-299 m can impair performance. Higher altitudes (≥ 1000 m) are generally required before decreases in discus performance, or enhancements in sprinting, triple-and long-jump, or hammer throw are seen.