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Friday, February 24, 2012

We see what we want to see

Sometimes we can easily miss what is right in front of us. We might miss the obvious! 


It might be because we usually concentrate so much in something that we miss other more important stuff. Usually we see what we want to see and we have no idea of what we have missed.


The video attached in this post is based on a famous experiment of Drs Dan Simons and Chris Chabris.
Watch the video below
http://www.youtube.com/watch?v=IGQmdoK_ZfY


If you want to read more please visit http://neuronarrative.wordpress.com/2010/07/27/did-you-see-the-gorilla-an-interview-with-psychologist-daniel-simons/

Monday, February 20, 2012

Is football performance affected immediately following local cooling?

Local cooling by application of ice or pre-exercise lower body cooling is a common practice in competitive football (http://georgenassis.blogspot.com/2011/10/post-training-muscle-cooling-may.html). Is performance affected by the use of these methods? How safe is it for the player when returning to the pitch?
A nice review article by Bleakly and colleagues (2012) has summarized the research findings in this area. Here are the main conclusions:
  • The majority of studies show a reduction in muscle strength immediately following cooling.
  • There is evidence than cooling negatively affects running speed, power and agility. However, this decline was alleviated with a short warm up.
  • Effect of cooling on endurance is not clear with some studies showing negative and some others positive effects. Those with positive effects asked subjects to exercise in the heat immediately after pre-cooling.

Points to consider when interpreting these findings
  • Cooling was mainly achieved with >20min of cold water immersion.
  • Performance remained below baseline for about 15min following cooling.
  • Effect of cooling on performance is affected by several factors such as limb adiposity.
  • There is very limited, if any, information in the literature on the effect of cooling on football skill performance.

For more reading
Bleakley et al. (2012). Should athletes return to sport after applying ice? Sports Medicine 42: 69-87.

Friday, February 17, 2012

Small-sided games: what’s new?

The primary aim of a recent study by Dellal and colleagues (2012) was to examine the influence of the number of small-sided games (SSG) on the physiological and technical responses. However, for the needs of this post I would like to stay on the comparison of the responses between the different SSG and not to discuss the effect of number of games.

What was the study's design?
Study sample was 20 international adult soccer players from a national team who participated in the 2010 FIFA world cup. Data were collected during the preparation period for the world cup. Players performed 3 different types of SSG:
  • 2 vs 2 (pitch size: 20 X 15m)
  • 3 vs 3 (pitch size: 25 X 18m)
  • 4 vs 4 (pitch size: 30 X 20m)

SSG were performed with 4 supporting players around the playing area and their duration was 2, 3 and 4min, respectively. Four sets of each SSG were performed at different training sessions with 3 min of passive recovery between each.  One important point to notice is that pitch size per player was constant for all SSG (1.75 m2).

Main findings

Table. Physiological and technical responses during various types small-sided games (average of 4 games for each type).

Variable
2 vs 2
3 vs 3
4 vs 4
Total distance covered (m)
304.2
531.2
668.4
Total distance covered in very high intensity (m)
48.8
87.7
91.2
Number of duels
7.1
7
4.4
Blood lactate (mmol/l)
3.6
3.4
2.8
RPE (0-10)
7.7
7.8
7.9
% maximal heart rate
90
89.4
85.5
No statistically significant difference was found between SSG.

Take-home messages
  1. Total distance covered tended to be greater in 4 vs 4 games.
  2. Players achieved almost the same % of maximum heart rate in all games. However, total distance covered in very high intensity running tended to be greater in the 4 vs 4 game.
  3. Number of duels tended to be greater in 2 vs 2 games.
  4. Finally, players reported similar level of fatigue after all 3 types of SSG.


Although the results refer to high-level adult players and no statistically significant difference was reported between the types of SSG, I think there are some messages to take that might apply to each one’s setting.

Reference
Dellal et al (2012). Variation of activity demands in small-sided soccer games. International Journal of Sports Medicine, in press.

Monday, February 13, 2012

Goal setting & Team building: applications of Stephen Covey’s ideas in football

Football is a team sport. This means that success is determined by the optimal combination of physical, tactical and technical skills of each one of the players. To train a team effectively, a coach must adjust personal characteristics to fit the team’s objectives and goal. Also, he needs to develop a strategy to translate goals into action. And then he must effectively communicate the goals to players and staff members.

There might be players that make no commitment to team’s goals? How can you, as a coach, get them involved? Goal setting is not an easy task.


Dr. Stephen Covey, one of 25 most influential American’s and an internationally respected leader has presented very nice work in his books. This is a video which I think apply also to football. Hope it helps you and gives you some ideas for your every day work in the field. 

Enjoy it! 

Saturday, February 4, 2012

Life is beautiful

Low-volume high-intensity interval training: what’s new?

From the Official website of Manchester City
A number of studies from Burgomaster and Gibala from McMaster University, Canada, have shown that low-volume high-intensity interval training (HIT) results in muscles’ adaptations and endurance performance improvements that are similar to those induced after the traditional endurance training. For example, in one of the first such studies by Gibala et al (2006) 16 healthy university students were assigned either to HIT or traditional endurance training group (ET). Training for the HIT group consisted of 4-6 repetitions of 30 sec “all-out” supramaximal exercise with 4 min recovery. In the ET group, individuals performed continuous 90-120 min cycling at 65% of their peak maximal oxygen uptake. Training was performed 3 times per week for 2 weeks in both groups. Training time (including rest periods) was 14-23 min for HIT and 90-120 min for ET. Endurance was assessed with time trials on the cycle ergometer and the average performance in this test was ~60min before training.

The results of this study showed that endurance performance was improved at the same degree with both low-volume high-intensity interval and continuous endurance training (Gibala et al., 2006). This effect was despite the fact that exercise volume and training time were much lower in HIT compared to ET (about 90% and 75% lower, respectively).

What’s new?
In a recent study, Jonathan Little and colleagues (2010) from the same research group, introduced a modified HIT realizing that it is hard for the individuals to perform repeated bouts of supramaximal exercise. In their study, they asked again seven men to train 3 times per week for 2 weeks with HIT. Training consisted of 8-12 repetitions of 60sec bouts at 100% of peak power output as it was previously determined on the cycle ergometer. Active cycling at low loads was introduced for 75sec between each sprint.

Their results showed that:
  1. Endurance performance was improved by 9-11% with HIT. This is a big change considering the timeframe it was achieved (over 2 weeks or 6 training sessions).
  2. This improvement was associated with increased skeletal muscle oxidative capacity. This indicates that HIT was effective in altering working muscles’ quality.


Do these changes translate in football match performance improvements?
We don't know. There are no studies to show the effect of this kind of HIT on football endurance. Of course, it is difficult to replicate the above mentioned training protocol in the field. More work is needed to define the most effective and practical protocol for HIT in the field. Iaia et al (2009) have shown that performing repeated sprints at 93% of the speed achieved in a 30sec “all-out” sprint run was effective in maintaining muscle oxidative capacity and endurance performance in well-trained runners.

Another limitation for the majority of above mentioned studies is that they used active and mainly non-trained individuals. So we do not know if these findings apply to highly trained football players. Besides that, one must remember that football is a multi-task sport and success is determined by a mixture of factors such as physical, tactical, technical, psychological and environmental.

General Comments
In my view HIT is a nice tool for endurance performance improvement in football players. However, only players that are used with performing repeated high intensity bouts could train this way effectively. I believe that before you apply this training method as fitness coaches you must consider the followings:
  • INTENSITY: the intensity is maximal and this will increase injury risk. In addition, a sudden change in training intensity may not always be beneficial.
  • DURATION: It seems that this training should incorporate bouts of 30-60 sec. This is a very hard training that stresses also the anaerobic lactic acid mechanism of energy production. Therefore, children and some adolescents should avoid this kind of training.


For more reading
  • Burgomaster et al (2005). Six sessions of sprint interval training increase muscle oxidative potential and cycle endurance capacity in humans. Journal of Applied Physiology 98, 1985-1990.
  • Gibala et al (2006). Short-term sprint interval versus traditional endurance training: similar initial adaptations in human skeletal muscle and exercise performance. Journal of Physiology 575, 901-911.
  • Iaia et al (2009). Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume. Journal of Applied Physiology 106, 73-80.
  • Little et al (2010). A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms. Journal of Physiology 588, 1011-1022.