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Monday, July 25, 2011

POSITIONAL SPECIFIC TRAINING

It has been shown in a number of studies that physical demands during the game vary with position. For instance, the greatest distance during the game is covered by the midfielders and the lowest by the center-backs. Wide midfielders cover more distance at high-intensity and sprinting than other players in the team. In addition, recovery time between high intensity bouts is lowest for wide midfielders and highest for central defenders (Bradley et al., 2009). No doubt, however, that central defenders need very good agility and low reaction time to follow their opponents. This information, that comes from Premier League analysis and data from other studies suggest that physical training of football players should differ according to their positional role in the team. 

To my knowledge there is only one study in the literature on the effect of positional specific training on physical parameters (DiSalvo and Pigozzi, 1998). In this study, regular training was supplemented with individual training according to the positional needs in top level players. The results showed greater improvements in physical performance in this group compared with the control group that followed the regular team’s training only. 

To my experience training according to the positional needs is important for both youth and adult players. At the highest level, however, time constraints may limit the use and thus the benefits of this kind of training particularly for players playing 2 matches per week.

Can we start positional specific training at young ages? Yes. In my opinion we can start specific fitness training from the ages of 15-16 years or as soon as players attain the peak velocity for height increase.

Friday, July 22, 2011

Sudden cardiac death in young athletes

Sports activity is associated with sudden cardiac death in individuals less than 35 years of age. The risk of a young dying suddenly during athletic activity ranges from 1 to 3 deaths per 100,000 persons year. In the USA, soccer contributes almost 6% of total deaths. In another study from Sweden, the majority of sudden deaths in young athletes was in football players. Pre-participation screening is advised to minimize the risk of death.

If you want to learn more on risk factors and screening process I suggest a recent article with free access following the link below

http://www.dovepress.com/articles.php?article_id=7923

“WINDOW OF ANABOLIC OPPORTUNITY”: concept & practical applications


“Window of anabolic opportunity” refers to the time period after exercise training when muscle protein synthesis is elevated. Which factors affect this anabolic response?

Exercise training or feeding? The general concept is that exercise is capable of turning on anabolic signaling and that feeding maximizes this effect. Indeed, studies show that resistance training induces an increase in muscle protein synthesis even in the absence of protein feeding. Protein intake and resistance training may increase muscle protein synthesis by about 15-25% compared with training alone (Phillips et al., 1997).

How long is anabolism sustained after exercise training? It seems that acute resistance exercise-induced muscle protein synthesis is sustained for 48h. The peak of muscle protein synthesis rate depends on training level. However the higher rate is observed at 4 hours post exercise in trained and around 16 hours in untrained individuals (Tang et al., 2008).

Does exercise intensity affect anabolic rate? Resistance exercise training at loads higher than 70% of maximal is required to stimulate muscle protein synthesis. In untrained subjects or untrained limbs, exercise intensities as low as 20-30% of maximum with working muscle blood flow occlusion may also stimulate muscle anabolism.

Does amino acid amount and type affect anabolism? Yes. It seems that essential amino acids (EAA) are necessary for the stimulation of muscle protein synthesis. The guidelines are for 20 g of intact dietary protein intake or 8-10 gr of EAA to maximize protein anabolism. Proteins that are digested at a fast rate such as whey or soy are the best choices.

Timing of amino acid ingestion: does it matter? Timing of ingestion is a major issue. Literature review suggests that an increase in amino acid availability in close time proximity with resistance training may be beneficial to muscle protein synthesis. More benefits are gained when amino acids are ingested either before or/and within 1 hour after resistance exercise.

For more reading
Phillips et al. Am J Physiol 273:E99-107, 1997
Tang et al. Am J Physiol 294:R172-178, 2008

Tuesday, July 12, 2011

OMEGA-3 FATTY ACIDS SUPPLEMENTATION TO FACILITATE RECOVERY AND ANABOLISM?

Omega-3 polyunsaturated fatty acids (omega-3 FA) have been shown to reduce high blood triglycerides concentration when combined with low-fat and low-cholesterol diet in clinical studies. In other studies, an increased amount of dietary long-chain omega-3 FA intake has been shown to improve anabolism in cachexia. Dr. Mittendorfer and her colleagues from Washington University School of Medicine, St Louis, U.S.A are the first scientists το examine the role of increased omega-3 dietary intake on anabolism in healthy individuals. In their study that was recently published, 9 healthy men supplemented their diet with omega-3 FA (4 g of Lovaza®/day) for 8 weeks. Their results showed that omega-3 FA supplementation has an anabolic effect in healthy individuals.

One important observation, is the anabolic effect was only when hyperinsulinaemia and hyperaminoacidaemia were presented. No anabolic effect was shown in response to omega-3 supplementation without hyperinsulineaemia. Although speculative, this means that to facilitate anabolism and recovery omega-3 supplements should be taken when blood insulin levels are high. High blood insulin is the response of a high carbohydrate (CHO) meal or CHO drink intake. More important, hyperinsulinaemia and probably hyperaminoacidaemia can be achieved with the co-ingestion of carbohydrate and protein after a match or exhaustive training, as discussed in my previous post.

Reference
Smith et al.  Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women, Clin Sci 121(6):267-78, 2011.

Monday, July 11, 2011

NUTRITIONAL STRATEGIES TO IMPROVE RECOVERY

Fast recovery after training/game is a key issue in modern football. The aims of any nutritional intervention at recovery are 1) to replenish energy stores, and 2) to repair tissues from  exercise-induced muscle damage. Here are some PRACTICAL key points on nutrition for FAST RECOVERY
  • ·         Start eating as soon as possible after the end of training that lowers muscle glycogen. Muscle glycogen can decline at a critical point after 90 min of match. 
  • ·         Carbohydrate (CHO) in a liquid or solid form is the most important determinant of muscle glycogen synthesis.
  • ·         Literature suggests that CHO intake should exceed 1.2 g/kg body weight/hour. Practically, this is a very large amount of CHO. Players should take as much CHO as possible within the first 2 hours after exhaustive exercise that lowers muscle glycogen.
  • ·         Co-ingestion of a small amount of protein (0.2-0.4 g/kg body weight/hour) with CHO (0.8 g/kg body weight/hour) seems to result in similar amount of muscle glycogen repletion compared with a high CHO intake of 1.2 g/kg body weight/hour. Thus, co-ingestion of CHO and protein may speed-up recovery.
  • ·         Protein and amino acid intake is suggested in order to stimulate muscle protein synthesis and inhibit protein breakdown.
  • ·         Players should consume about 20gr of protein during the first hour of post exercise recovery. Protein intake should be encouraged during the day to maximize muscle protein synthesis rate.
  • ·         Replacement of fluid losses is also necessary particularly when exercise is performed in warm weather.

Thursday, July 7, 2011

SOME THOUGHTS ON THE USE OF WATER IMMERSION IN RECOVERY

Water immersion is a popular means for recovery in football players. What is the scientific evidence behind it?

What is the aim of water immersion?
The aim of this strategy is to improve recovery after damaging exercise. There is also evidence that water immersion can minimize inflammation observed after exercise. Upright water immersion at the hip or chest level improves venous blood return and thus removal of metabolic by-products from the working legs. This is due to the external high pressure imposed to the legs vessels with upright immersion.


What do studies suggest?
Three main strategies are described in the literature: cold water, thermo-neutral water and contrast therapy (alternating cold and hot water immersion). Research findings are controversial. Some studies report an improvement in sprint performance 24 and 48 hours after exhaustive exercise by using cold water immersion immediately after exercise. Other studies fail to replicate these findings. The contradictory results could be due to several reasons: different subjects, protocols, level of damaging exercise, immersion protocol and water temperature etc. The common finding in most studies is that cold water immersion results in better feeling of legs pain after 24 and 48 hours of damaging exercise.

What is the suggested protocol for cold water immersion
Most of the studies suggest 5-15 min of water immersion at 10-15 oC immediately after exercise.

Conclusion
So far there is no strong evidence-based knowledge on the beneficial effect of cold water immersion on recovery and performance 24 and 48 hours after damaging exercise. It seems however, that players’ feeling of fatigue and muscle soreness is improved with this recovery strategy.

Simple means to improve recovery after damaging exercise
  1. COOL-DOWN. In my opinion this is important to speed up recovery. Ideally, 10-20 min of running at 60-70% of maximum heart rate is an effective way to increase blood flow at the legs.
  2. Additional strategies THAT SHOULD COMPLEMENT AND NOT REPLACE COOL-DOWN. These include water immersion, ice placement, nutritional interventions etc. I will come back on these strategies with a future post.


Questions with practical applications
  1. It seems that cold water immersion, at least of adequate duration, stimulates sympathetic nervous system. This will retard the recovery process. What is the appropriate water immersion or recovery strategy to avoid sympathetic stimulation and stimulate parasympathetic response instead?
  2. Cold water immersion minimizes inflammation due to exercise. This might suppress training adaptations since there is a link between exercise-induced inflammation and adaptations. What is the appropriate recovery strategy to improve performance recovery while not interfering with the adaptations process?
For more reading
Bleakley and Davison. Br J Sports Med 44: 179-187, 2010 (Review paper)
Vaile et al. Int J Sports Med 29: 539-544, 2008

Sunday, July 3, 2011

A SIMPLE WAY TO MONITOR INDIVIDUAL TRAINING LOAD

In football, as in most team sports, training is similar for all players, at least most of the time. Research has shown that during small-sided games players with high VO2max work at lower relative intensity compared with players with lower VO2max. This may cause two problems 1) some players train and thus improve more than others, and 2) some players may train very hard and if continue for weeks they can reach overreaching and overtraining.
Monitoring individual internal load, or the load imposed on the player´s body, by each training session is of high importance in modern football. One approach to do so is by multiplying the whole training rate of perceived exertion (RPE) by its duration. RPE should be recorded 30min after training using the category ratio scale (Borg scale) modified by Foster et al. (1995). Please note that rating should be based on the players feeling for the entire session.

Table.  0-10 Borg scale to use with football players (Impellizzeri et al., 2004).
Rating

0
REST
1
Very, very easy
2
Easy
3
Moderate
4
Somewhat hard
5
Hard
6

7
Very hard
8

9

10
Maximal


Reference
Impellizzeri et al. Med Sci Sports Exerc 36:1042-7, 2004