Monday 31 December 2007

Recovery and regeneration: what is happening in elite sport?

In the last few years I have observed a steep increase in interest versus recovery and regeneration strategies.

Athletes train and compete a lot these days and everyone feels the need to provide recovery and regeneration strategies to speed-up return to optimal functions.

I have to say that the quality and the science behind most of the recovery modalities is quite questionable and most of the times, the appropriateness of such modalities, could really be a matter of serious debates.

It is not the aim of this article to discuss recovery and regeneration, I promise I will write a more detailed article on this topic in the next few weeks.

In this article I would like to write about the fact that many elite training centres and Olympic associations are investing a lot of money into recovery and regeneration centres aimed at helping athletes.

In september 2006, the USOC opened a New Athlete recovery centre investing a lot of money in conventional and non-conventional recovery modalities/devices (http://usocpressbox.org/usoc/pressbox.nsf/6272c9a938d3a5cb8525711000564abd/aad006ac4a40193e852571ea0068b36d?OpenDocument).

The Australian Institute of Sport (AIS) recently spent 3.5 AUD millions to create the new Recovery Centre (http://www.ausport.gov.au/journals/ausport/Vol3no2/32new_ais.pdf) to provide this service to Australian Athletes.

The Japanese Olympic Association is also building a new site where recovery services will also be provided.

Many leading countries are investing in this area, however research in the most common recovery modalities is scarce or of poor quality. I expect an increase in the number of research studies in this area and I can already anticipate that many modalities currently used by famous athletes/teams will be shown not to be as effective as advertised!

Saturday 22 December 2007

Excel Add-ins

Many sports scientist use spreadsheets to analyse data, prepare training programmes and/or deal with complex numbers or formulas. Microsoft excel is probably the most used spreadsheet in the sports science community.

Before suggesting some useful add-ins, I would like to remind readers that a free product with all the capabilities of Microsoft office can be downloaded for free at:

www.openoffice.org

The quality of this software is immense and it is fully compatible with Microsoft products. This is an open source project which allows anyone to have a good quality software without paying a penny.

The following screen shot is just an example of the amazing capabilities of the spreadsheet:

 

So, if you are in need to such a software have a look at it, it is free.

I recently installed a very useful add-in for excel provided by ASAP utilities. It really speeds up all the work I do on spreadsheets and it is now an invaluable tool for me.

http://www.asap-utilities.com/download-asap-utilities.php

If you are an individual user you can download it for free.

More information will appear on this blog on softwares/spreadsheets and any possible free resources on the web that could be useful for a Sports Scientist. So, stay tuned!

Wednesday 19 December 2007

New Technology: Polar RS800 SD

I want to use this blog also to present some innovative technology I come across or help develop as I think modern sports scientists need to be aware of novel technologies and be able to make informed decisions on which tools they need to do their work the best they can.

Of course It is not the intention of this blog to be some form of advertisement for products/methods/procedures. The aim of the blog is in fact to provide unbiased information. When a possible conflict of interest could be present I will clearly describe my relationship with any company.

The product I am presenting in this article is genuinely exciting and improves our ability to monitor running sessions. Hence the reason to present some information on this blog.

I had the pleasure in the past months to work with Polar Electro (www.polar.fi) on this innovative technology which will definitively help many sports scientists.

The Polar RS800 SD is a novel running computer that allows the measurement of Heart Rate and Heart Rate variability synchronised with running mechanics parameters (stride frequency/length/pace etc etc.).

 

Polar RS800 SD

This is really a great product, running distance is measured during each run using a very simple Stride Sensor without the need of GPS. This means you can measure your running efforts also indoor.

It is very precise and extremely reliable and valid as demonstrated in our study presented at the American College of Sports Medicine annual conference in New Orleans last May.

The combination of HR and mechanical information allowed the development of a novel running monitoring tool called Running Index, this index can be measured in each running session and can provide indications of how training is affecting both fitness and running mechanics.

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Furthermore, the integration with Adidas in the Fusion system (clothing/shoes/running computer; www.adidas-polar.com) allows each athlete to use this technology attaching the chest receiver to t-shirts or bras and enclosing the Stride Sensor into the shoe insole.

 

fusion 

Finally with this technology a coach can email the athlete a training programme indicating not only Heart Rate zones, but also pacing strategies that the athlete can follow on the running computer.

Each training session can also be analysed looking at a combination of HR and mechanical data:

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All in all, a great tool to use for training planning and monitoring and also for research use. We will be publishing soon the results of our research studies validating and using this technology.

 

Disclaimer: The author of this article is a consultant to Polar Electro. 

Saturday 8 December 2007

Testing team sports athletes and analysing data

Many strength and conditioning coaches and/or exercise physiologists are nowadays employed to work with team sports. Testing and monitoring training is now becoming standard practice and data analysis, data mining and the ability to produce meaningful reports is a necessary skill of the elite sports science support staff. I this short post I will not discuss the main aspects to consider when performing a test and/or the limitations of testing procedures. I will just present simple examples of reporting data using Microsoft Excel.

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When dealing with large squads, single athlete's scores should be analysed and continuously monitored to make sure the athlete is progressing and improving. However, in order to profile areas of improvement it is important to compare the single athlete to the group or to a known group of elite performers.

A very simple way for doing this with excel is to collect all the data in a single sheet with the name of the athlete in the first column and all the tests scores in the following columns. Then, when the average values and the standard deviation for the team is calculated, all scores of each individual player can be transformed in Z-Scores. In Excel this is possible using the function STANDARDIZE which returns a normalised value from a distribution characterised by mean and standard deviation.

The syntax is the following:

STANDARDIZE(x,mean,standard_dev)

X   is the value you want to normalize.

Mean   is the arithmetic mean of the distribution.

Standard_dev   is the standard deviation of the distribution.

Once each score is normalised, spider charts can be used to see how each individual player scores as compared to the team scores. Two examples are given here. Zero is the team score, every score higher than zero means that the athlete scored better than the average value, every score below zero means that the athlete scored less than the average value.

Figure 1: This is an athlete that outscores the team average values in all tests

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Figure 2. This is an athlete outscored team results only in sprinting.

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When we plot the results in this way we can clearly identify areas where we need to make an impact with a training programme. So, while in athlete JL we need to put a lot of emphasis on sprinting abilities, on athlete H we need to do a lot of work on strength and power. With this approach we can then track not only athlete's development in different areas but also how they evolve in comparison to his/her team scores. Individualization of training is the key aspect to take into consideration when working in team sports. Data analysis allows the coach, the physiologist and the sports scientist to profile each individual player and provide appropriate training interventions.

Saturday 1 December 2007

Strength training in volleyball: Periodization and other issues

Professional volleyball is becoming more and more demanding from a physical standpoint. The number of competitions is increasing and elite players are involved in those all-year-round. In fact, players involved in club championships and national team tournaments play a very high number of matches and have very few rest periods during the year. We could say that the sporting season for those individuals is never-ending. If we also consider top clubs, we can easily see that during the last years the number of matches increased. This is due to the fact that top teams are not only involved in playing the national championship, but also in national and European cups. This increased demand is of course changing the way physical conditioning was done before. Nowadays there is a need for a correct planning of the activities, travels and rest periods in order to be able to avoid overuse injuries, overtraning and underperformance. The key for being able to prevent all of the above is a very well planned periodization, which needs to be monitored on a weekly basis and corrected during the season. Before planning any type of program it is important to be aware what are the physical demands of the game. Some players play different positions and so have different needs (i.e. Libero, Setter and Opposite). Then, it is important to establish individual characteristics (and performance level). In this connection it should be pointed that appropriate tests should be utilised in order to gain information which could be useful in the development of the training program itself. The training programme should then be individualised based upon each player's individual characteristics.

The periodization plan has to take into account the official and friendly matches, the rest periods and the total number of training sessions.

Strength training sessions can be planned during the competitive season if a proper work-to-rest planning is performed. Testing and training monitoring is extremely important, since it is the only way to determine adaptations and prevent overtraining syndrome or underperformance. By controlling adaptations we are in fact able to re-evaluate athletes’ level of performance and then we can change the training methodology, the exercises and the program itself and be able to have further improvements.

With this in mind, before coming to some practical examples, it is important to re-consider some of the concepts behind periodization.

Strength training, periodization and volleyball

Strength training should be implemented in volleyball not only to improve jumping ability and spiking velocity. Volleyball performance is characterised also by the ability to maintain a good balanced position when receiving and passing the ball, performing a dig or a block and sustaining the impact of fast balls with the upper body. Strength training should be then directed and focused not only on the lower limbs but also on the upper limbs and the trunk most of all to avoid injuries, but also with the view of improving some specific technical skills.

Most of the research studies published in the literature have been carried out using physical educations students, untrained people or recreational players, and we all know that training an elite athlete is a different issue. The higher the level of the athlete, the more difficult is produce enhancement of performance. However, the principles presented in this blog article could be extended to all type of volleyball players.

Before discussing periodization, it is important to remind what are the effects of strength training exercises. The adaptation to the training stimulus is related to the modification induced by the repetition of daily exercise, and is specific for the movement executed (Edington and Edgerton, 1976). These adaptations are related to the fact that human skeletal muscle is a specialized tissue which modifies its overall function capacity in response to chronic exercise with high loads (McDonagh and Davies, 1984). The above mentioned findings all suggest that resistance exercise can be an effective means for enhancing neuromuscular performance. In this connection it should be noticed that changes within the muscle itself constitute the most important adaptation to resistance exercise (Sale, 1988; Behm, 1995). In fact, strength training response has been shown to be mediated by both neurogenic and myogenic factors (Moritani and De Vries, 1979). Neural adaptations have been indicated as the first changes occurring in the muscle, permitting gains in muscle strength and power in the early stages of a resistance exercise program in the absence of increase in cross-sectional area of the muscle (Behm, 1995; Costill et al. 1979; Sale, 1988). It has been also demonstrated that specific adaptations occur depending on the training program implemented (Sale and Mc Dougall, 1981). Strength training then, can be considered a training stimulus which produces specific adaptations on human skeletal muscles, based upon the protocol utilized for training. The specificity effect of strength training has been underlined by many authors (Sale, 1988; Behm, 1995; Morrisey et al. 1995; Bandy et al. 1990) and the velocity specificity effect has been suggested as one of the most interesting outcome of resistance exercise programs. However, even if the mechanisms underlining this velocity-specificity effect have not been clearly defined, most importance has been given to neural adaptations such as improved coordination, increased activation of prime movers muscles (Moritani and De Vries, 1979) recruitment and synchronization.

It appears then clear that with strength training the neuromuscular system is able to perform to a higher level. It is also clear that several neurological mechanisms are involved in the early gains, with hypertrophy being the last step of the adaptations process. Strength training impacts several systems, in fact endocrine, skeletal, metabolic, immune, neural and respiratory acute and chronic responses have been observed following single bouts or repeated bouts of strength training.

With this in mind we have then to say that the careful selection of the training variables (volume, intensity, density and exercises) determines the effectiveness of the program. Exercises should be chosen based upon the possibility of transfer in competition-specific motions. The parameters to control such outcome are very simple: muscle-joint mechanics and muscular activation timing.

Let’s consider the first one. In volleyball one of the most important actions is the volleyball spike. This technical motion is performed with a stretch-shortening cycle of the leg’s extensors muscles. We know the muscles involved in such motion and we know the mechanics (stretch-shortening cycle). We also know that this motion is a closed chain-type of activity. Hence, when choosing the exercises the movement patterns should mostly be characterised by closed-chain-type of activities which simulate similar mechanics.

Let’s now consider another aspect: timing of muscle activation. The jump and spike action in volleyball, depending upon the technique utilised, is performed with lower limbs muscles performing mechanical work for a duration ranging from 300 to 450 milliseconds (Bosco, 1985; Coutts, 1982; Viitasalo, 1982). Similar times were also measured in 1 legged spike actions Huang et al. (1999). Specific exercises should also be included in the training plan repeating timing and patterns of activation.

Now then, we know that general strength training is good for enhancing neuromuscular performance and that adaptations are stimulus-specific. We also know that the specific performance demands are related to the capability of an athlete to express maximal power in limited amount of time.

Let’s now discuss periodization in elite volleyball. It is important to say that the earlier model developed by Matveyev and presented in most books of training methodology should be considered only as a pedagogical model, and not as a real model to be based on. Most of all, it should be pointed that most of the periodization models have been developed for individual sports and cyclic activities (running, rowing, cycling) and there is at the moment no model available for team sports demands. So, we should re-consider all the information which is available on this topic. From a pedagogical standpoint some concepts of periodization are important.

It is in fact the definition of specific work to rest ratios, volume undulations, and intensity undulations, that defines effective training cycles. However it should be pointed out that what is good for a team cannot be good for another one, since there are different individuals and different athletic levels. This means quite frankly that it is impossible to have an "optimal model". There are however general concepts which are useful for developing an effective periodization model.

In most American books periodization is divided into 3 phases: preparatory, competitive and transition phase. We know that nowadays top volleyball players have a very long competitive season and a very short preparatory and transition phases. Lower level players of course have the luxury of time and could spend more time in preparation and/or transition. If we look at the typical playing patterns of international players and the typical club and national team calendar of elite European nations we can see how some players move from Club activity to an intense summer of International activity to then start again in the Club with minimal time for recovery and almost no time to train before getting involved in further competitions.

In many books an optimal progression is suggested for strength training: anatomical adaptation phase, hypertrophy phase, maximum strength phase, conversion phase and maintenance phase. Those concepts are of course based upon the structure of the sport season in USA where the competitive season is relatively short as compared to Europe and there is a lot of time for preparing the season itself, with almost no time during the competitions.

I take the liberty to state that this approach is wrong in European sporting seasons in most team sports. For sure, be able to go through all of the above mentioned phases, we should have enough time. We all know there is no time (and this is not a bad thing sometimes…). Hence, the solution is a different approach to strength training.

In this approach approach, maximal dynamic and explosive-type loads have to be used concurrently, in order to gain force and power at same time. Of course a good planning should change during the season the percentage of volume dedicated to one or the other, but during the whole season both have to be trained. The key for understanding when and if it is time to change something in the training program is testing.

Adaptations to strength training programs depend on the type of muscular activation, intensity and volume (Sale & Mac Dougall, 1981; Atha, 1981). We know in fact that training strength utilising heavy loads and low contraction speed determine enhancement of maximal dynamic strength (Berger, 1962; Hakkinen, 1994). However, it is important to say that in order to produce enhancement in power and explosive-type motions, those loads have to be lifted with the highest possible speed and lighter loads have to be utilised as well (Berger, 1963; Hakkinen, 1994; Kaneko et al., 1983; Moritani et al. 1987). The combined methodology has been shown to be productive in enhancing a wider spectrum of the force/velocity capabilities of skeletal muscles (Harris et al., 2000; Newton & Kraemer, 1994; Stone, 1993; Stone et al. 1980).

The characteristics of the explosive-power exercises must be short duration (200-300msec) and high intensity. An example of the different activation patterns are presented in Figures 1 and 2. In this case a professional female volleyball player was performing half squat with 70% of 1RM and drop jumps from a box 40cm high starting with knee bent at 90°. Here it is possible to see the different EMG activity and the duration of the mechanical work. This is an example of the different timing and muscle activation patterns in different exercises. Again, this is a support of this “muscle tuning” approach to strength training. The aim is to permit to the neuromuscular system to express its maximum in a working time spectrum which is the characteristic of the performance demand. So, when choosing the exercises and developing a program, always there is a need of using combined exercises (maximal dynamic strength and explosive strength).

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Figure 1. Half Squat with 70% of 1RM load. Biomechanical Analysis

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Figure 2. Drop Jump. Biomechanical Analysis

Concluding remarks

It is impossible to have a specific model for planning a season in team sport. The periodization plan should take into account the level of the team, the competitions, the number of the players available, the travelling schedules and many other aspects. Most of the times, what is planned at the beginning needs to be changed, due to the results and participation to different competitions (European Cups, Play-offs…). It means that the only way to try not to make mistakes leading to overtraining or underperformance is to test routinely the players and adjust the programme allowing appropriate rest-to-work ratios. Of course it is important in the pre-competitive phase to increase the training volume to build up maximal dynamic strength mostly and endurance to the game throughout game-like drills. Then, it is possible to increase intensity, increase the amount of explosive-type exercises and put more emphasis on speed-strength drills. Rest is important, if your players have enough rest they will perform always well not only in competition but also when intense technical and tactical sessions are planned. Sometimes it is better allowing one or two days off rather then exaggerating with training sessions. One main rule: if the players are tired, the best training is rest and recovery!

In the following figures there are examples of the training load (always referred only to the strength training sessions) of professional female volleyball teams participating in various competitions. As you can see two teams with two different load distributions can still improve vertical jumping ability. In one case at a certain time of the season due to a high density of competitions, the training load was lowered to maintain the level reached and avoid overtraining. In the second case, a different approach was used since the goals and the characteristics of the team were different.

These are only examples of how to manage and plan the season. The most important aspect to remember is that without a proper testing and monitoring procedure you would never be able to understand if the plan is effective or not and most of all, in which direction adaptations are going (are the players gaining strength, power or both?). Without this approach, training becomes just a blind guess which is unlikely to produce performance gains.

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Figure 3. Training load and vertical jumping ability in a professional volleyball team participating in the Spanish League, Spanish Cup and European Champion's League (average values n=10)

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Figure 4. Training load and vertical jumping ability in a professional volleyball team participating in the Italian League and Italian Cup (average values n=10)

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