Wednesday, April 11, 2012

Practical Tips and Women's Soccer

Hey Chris,

I have been reading your blog and just want to say thanks for writing down your thoughts. There is a dearth of usable information on Polar Training Loads, etc for soccer on  the internet. There are plenty of academic papers but they don't contain a lot of practical information for coaches. Your blog has a lot of useful information. 

We recently invested in a Team 2 system and I had a couple of questions to ask you…

- have you seen noticeable differences in workloads between the men's and women's teams?

“physiologically”, I’m not aware of any information that would say that there would be a difference between men’s and women’s teams.  The major factor going into the training load calculation is heart rate based on a percentage of maximum for each individual.  So again, if you have fairly accurate heart rate max values for each individual there should not be a difference based on gender.  The other factor would be each individuals anaerobic threshold (AT), but again, I have not seen any information regarding differences in gender on this variable either.  With regard to AT, I have not found a simple field test to determine AT.  I wish I could, as setting up their heart rate zone values based around AT would yield a much more accurate reflection of total training load.  Current AT testing is laboratory based and other methods, like looking for the heart rate deflection point, are much less accurate and leave a lot open for interpretation. 

You used the term “differences in workloads”.  I always want to point out that what you are seeing from a “training load” standpoint is not a “work load”, rather it is the “effort” of an individual.  For example a highly fit player may run more distance, more sprints, more changes of direction, etc. than a less fit player thus doing much more work; but the less fit player may actually expend greater effort doing less work (less distance, less sprints, etc.).

So to answer the question “do I see noticeable differences in workloads between the men’s and women’s teams”, I would say that with differences in coaching style, practice structure and practice duration I do see differences between the men’s and women’s teams.

From a rough initial scan of the data provided in the study below, there appears to be a similar workload in females as compared to males. 

Med Sci Sports Exerc. 2005 Jul;37(7):1242-8.
Physical demands during an elite female soccer game: importance of training status.
Institute of Exercise and Sport Sciences, Department of Human Physiology, University of Copenhagen, Denmark.
To examine the activity profile and physical loading of elite female soccer players during match play and to study the relationship between training status and physical match performance.
Time-motion analysis and HR recordings were performed on 14 elite female soccer players during competitive matches. In addition, the players carried out a laboratory treadmill test and the Yo-Yo intermittent recovery test.
The total distance covered during a game was 10.3 km (range: 9.7-11.3) with high-intensity running (HIR) accounting for 1.31 km (0.71-1.70). HIR was performed 125 times (72-159) for 2.3 s (2.0-2.4) on average. The average and peak HR in a game were 167 beats per minute (bpm) (152-186) and 186 (171-205), respectively, corresponding to 87% (81-93) and 97% (96-100) of HR(max). Maximal pulmonary oxygen uptake (VO2max) was 49.4 mL.min(-1).kg(-1) (43.4-56.8), and incremental treadmill test (ITT) performance was 4.49 min (3.38-5.17). The Yo-Yo test performance was 1379 m (600-1960). The total distance covered during match play did not correlate with VO2max or ITT performance but correlated with the Yo-Yo test result (r = 0.56, P < 0.05). Significant positive correlations were observed between HIR and VO2max (r = 0.81, P < 0.05), ITT (r = 0.82, P < 0.05), and Yo-Yo test performance (r = 0.76, P < 0.05). No relationship was observed between HR(max) during match play and any of the performance measures.
The present study demonstrated that 1) HIR during games varies markedly between elite female soccer players, 2) all players have high HR throughout a competitive game with periods of near-maximal values, 3) the distance covered by HIR during match play is closely related to the physical capacity, and 4) the Yo-Yo intermittent recovery test can be used as an indicator of the physical match performance of elite female players.

- what is a "normal" weekly workload for the women's team?

Again, training load is highly dependent upon coaching style, practice structure and practice duration.  To be direct in answering the question, I have seen training loads of up to 1500 points in a week with a team average around 800.  It is important to emphasize that I believe that we should exercise caution in applying too much volume via training load, that we also need to consider intensity as a major factor in developing and maintaining fitness.  Take the following example; a total weekly training load of 1000 points but with only 100 points coming from the top 2 zones (80-100% hrm) vs. a total weekly training load of 600 points with 300 points coming from the top 2 zones.  While the total volume of the latter session is rougly 1/3 less, the intensity is 3 times higher.  So in the end, you may look at your team (from a visual performance standpoint) and say we need to increase our fitness level, just increasing training load may not be appropriate.  It may be necessary to actually decrease training load but increase the intensity to gain fitness. 

- how do you incorporate weight training in the season, with so few points to throw around in the fall?

GOOD QUESTION!  The collegiate season is tough with 2-3 games per week; take a typical weekly game rhythm of games Friday and Sunday.  Let’s plan the week . . . Thursday will need to be a light session, Saturday will need to be a light session oriented around regeneration, so now you have Monday, Tuesday and Wednesday to work with . . . one of which has to be a day off!  I believe that the best choice for the off day would be Tuesday.  Here’s why: as you look at the “training load and recovery” graph, you’ll see that while the initial recovery curve begins to drop immediately after the event, there is a secondary rise in the recovery curve (this is usually only evident with very high intensity activity, like a game, or a novel exercise program).  The initial drop in the recovery curve depicts the refilling of energy systems, aka: metabolic recovery.  This tends to happen rather quickly and in all but extreme cases is usually complete within about 6-12hrs.  The secondary rise in the recovery curve depicts the pain and inflammatory recovery process.  With higher intensities the musculo-skeletal forces are greater resulting in increasing tissue stress and breakdown.  This pain/inflammatory process can take anywhere from 24-72hrs.  So, back to the weekly training rhythm . . . I believe that it is more appropriate to use the Monday session as a regeneration/recovery session.  This is also where I would incorporate weight training.  I can understand that this may be counter intuitive as increasing the musculo-skeletal stress at this time could increase the pain/inflammatory process, but I believe that you can more easily control the stresses in a weight training session, especially the velocity of the movement and the stretch shortening cycle where the muscle/tendon move ballistically from and stretching to shortening (where most of the tissue damage occurs).  So, while I would avoid high velocity lifting movements on this “recovery” day, I would emphasize controlled tempo movements.  This loading on the musculo-skeletal system will also aid in the anabolic hormonal state that aids in tissue growth and repair.  The Tuesday would be the off day and Wednesday the “hard” training session for the week. 

Now, I understand that coaches don’t always like this training rhythm, because now you have only 1 “hard” training session in the week; remember Thursday is light the day before the game.  You could certainly take Monday off and train Tuesday and Wednesday and you may find this works for a period of time.  My belief is that while this may provide for more time to “teach and coach”, it is not optimal physically and over a longer period of time will begin to take a toll.  As a coach, you must weigh the risk/reward scenario. 

I would also encourage doing a weight lifting session on Wednesdays.  You have to think a little out of the norm on these weight training sessions.  1 hour per session is too long.  Perhaps on Mondays in conjunction with some light aerobic work and mobility work the session will be an hour, but on Wednesdays the session should be brief and to the point; you can incorporate this lift on the front end of practice so that the players come out ready to train (no warm-up time needed) or at the end of the session.  Ideally, we’d do the lift and practice in morning and evening, but let’s be realistic, these are college kids. 

Last, your question was incorporating weight training “with so few points to throw around in the fall”.  Understand that intensity and effort as shown through the training load feature are based on heart rate.  While heart rate has been shown to be an accurate representation of intensity and effort in high intensity intermittent type sports, it may not be the best indicator of intensity and effort in other activities, such as weight training.  If we could accurately measure cardiovascular stress, musculo-skeletal stress, neurological stress and hormonal stress (to name a few) we could say that in high intensity intermittent sports, cardiovascular stress is a good indicator of the overall stress on the system.  However, in weight training, musculo-skeletal stress and/or neurological stress are likely much greater than would be represented by the cardiovascular system.  This isn’t bad! Meaning that if it’s more stressful than the heart rate shows that we should be even more concerned about limiting it!  This is not true.  It is a completely different system.  You can put the best gas in your car, but if your tires are flat your gas mileage is going to suck!  So, while total system stress or the combined stress of all systems should be considered (and can be with heart rate variability . . . more later) you should think about maximizing the condition and state of each system individually. 

The holy grail of measuring total system stress seems to be found in heart rate variability (HRV) . . . which the T2 can monitor!  Polar just needs to come up with the software to interpret HRV to relay meaningful results. 

- how do you interpret the Training Load & Recovery graphs? 

I discussed this in the last question, but let me say that the recovery curve is based on mathematical algorithms.  Given constant metabolic and musculo-skeletal recovery rates the curve should be accurate, however, we know that in college athletes nothing is very constant.  Sleep, nutrition, hydration and other recovery practices can vastly influence the recovery rate of each individual. 

- I have attached a graph for one of our players this past week - we played 2 1-hour games on 3/24, a 1-hour game on 3/31, and a 90-minute game on 4/1.
- what do the undulations in the graph actually mean? (is that muscle growth where it goes back up)

A potential problem with the training load and recovery graph is that I don’t believe there is a cumulative factor.  Meaning that if someone is not fully recovered and engages in another intensive session it does not depress the recovery rate further; it simply gives recovery rates for each individual session.  Certainly your player was under some pretty good stress in this week.  However, you did a very nice job of decreasing training load and intensity (I’m guessing you decreased the intensity because there is not a secondary rise in the recovery curve which we typically see with high intensity efforts).  Again, with the understanding that each recovery curve is specific for that training load, it could be that the lower training load and intensity session actually would aid in accelerating the recovery from the previous day. 

- is there correlation between the overlapped red zones and muscle soreness/soft tissue injury/overall fatigue?

Yes, I believe there is a correlation between the overlapped red zones and overall fatigue.  This is where, as a coach, I always interview my athletes and ask them how they’re feeling.  Some may be able to tolerate this better than others, which may be because they have better recovery habits.  Overall, you may find that they did not feel that fatigued in this given week, but continuing training at this level will eventually lead to chronic fatigue. 

From the other side of the coin, what are the selling points for the athletes (we as coaches know what we can get out of it). 

I think the selling points for the athletes is in addressing their recovery strategies.  Sleep, nutrition, hydration, cold tubs, etc. can all influence the rate of recovery.  The most important element of training is not the response that you get from training.  The response is not what you’re looking for in your athletes; fatigue, muscle soreness, etc.  The most important element of training is the adaptation.  The response (negative) triggers the adaptation (positive).  The adaptation occurs in the time subsequent to training.  Their actions in the areas of sleep, nutrition, hydration etc. will allow them to maximize the effects/adaptations to training. 

If you have the time to answer some of these questions, I would really appreciate it.