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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.


Saturday, April 18, 2015

Performance during the 2014 FIFA World Cup: download free from BJSM









The association of environmental heat stress with performance: analysis of the 2014 FIFA World Cup Brazil

  • George P Nassis
  • Joao Brito
  • Jiri Dvorak
  • Hakim Chalabi
  • Sebastien Racinais
Br J Sports Med 2015;49:609-613 Published Online First: 17 February 2015

http://bjsm.bmj.com/content/49/9/609.full.pdf+html

Tuesday, February 24, 2015

Does heat affect football performance?


To contribute into this discussion we have analyzed performance data during the 2014 FIFA World Cup BrazilTM in relation to environmental heat stress. A summary of the findings is presented in this table. 


Soon, the full paper will have open access.

Saturday, January 31, 2015

Think different, innovative & act effectively


















Here I am again after a period of silence. This was intentional to re-think the approach. As you can see, I decided to “re-brand” the blog to make it more useful (I hope!). Why this change?

Think different: I believe to make a step forward we need to look at things from a different angle. Not necessarily good but, for sure, we learn a lot.

Think innovative: I know this is a “big” word. Nowadays, many experts talk about innovation. I am not an expert but I think if we learn to look from a different angle or read below the lines we might find some good stuff.

Act effectively: To my experience, this is what is missing in sports & exercise science; the link between science and practice. The trend these years is to move towards “translation research” meaning research that will seek to answer practical questions & which will make the difference on the field. Again, this is not the end of the story. A key step in achieving this translation is the effective communication between the scientists and the practitioners.

Everyone has examples of ineffective plans. As an example, if training load is a key parameter in injury prevention in elite football, why many elite clubs don’t use this tool effectively? If science and medicine have made advancements in injury prevention why the rate of non-contact injuries remains high?

In the public health domain, why the vast majority of people do not take regular physical activity? This is despite the huge number of studies showing that regular physical activity protects from premature death.

Do we miss something?

I am happy to post your thought & ideas under the condition you identify yourself.

Hope you enjoy the posts from today. 

Regards

George

PS: The next 2 posts will be on the two examples I brought to your attention above. Stay tuned!