Last Updated on March 10, 2013 by Jimson Lee
This is Part 10 of the weekly “Friday Five” series where I ask 5 tough questions to world class elite coaches. To recap:
- Jumps coach Boo Schexnayder
- Dr. Mike Stone of the USOC and NBA
- Performance specialist Henk Kraaijenhof
- USA’s Dan Pfaff, now with UKA
- Pierre-Jean Vazel of the French National Team
- USATF Chair for Men’s & Women’s High Jump Dave Kerin
- Michigan State University’s Randy Gillon
- Harvard/UTEP/Portland State/Syracuse’s Kebba Tolbert
- Performance consultant and EU Basketball S&C coach Jose Fernandez
Tapani Keränen is a biomechanists at KIHU – the Research Institute for Olympic Sports in Jyväskylä, Finland. He has participated in many of the studies carried out about the hurdles and jumps. Tapani is also a coach and has the ability to help coaches to understand the biomechanics in an easy manner.
Friday Five is sponsored by Freelap Track and Field, a leader in electronic timing.
Interview with Tapani Keränen: 5 Questions
Q1 – SpeedEndurance.com: In your landmark presentation on Overtraining in 2004 in Stockholm you were talking about HRV as you have great experience working with elite athletes in Finland. Fast forward to two Olympics later HRV is now on the iPhone and many speed and power sports are trying to get a simple gage of fatigue and training balance in professional sports.
Without getting into sympathetic and parasympathetic form could you talk about fatigue from training factors of speed and power athletes such as sprint volumes on the track and sets and reps in the weight room and general patterns of HRV change? What should coaches be looking for visually and verbally with athletes to see how their own programs are working?
Tapani Keränen: I think it is limited. High sympathetic drive can be sign of stress, but also increased power output state. It needs something more than just HRV to monitor power athletes recovery state. It seems quite evident that HRV is a good recovery state measuring system for endurance athletes. For power athletes and athletes whose training is mostly interval type the HRV is not a great system. Maybe some kind explosive performance tests, like shot throws and standing long jump, reflects well enough their recovery state.
Generally the highest power is achieved with 70 % weights and 100 % effort. According to our experience during one set the highest power is reached at the third or fourth rep. Interestingly the very same reps produces also the largest power in max effort hurdle jumps. Usually at the rep number 6 – 8 the power decreases under the value of the first one. But strong verbal encourage increases the power output higher level for the next one or two reps.
Petterson et al (2005) made an excellent meta-analysis of strength training intensity and volume. According to his paper well trained athletes gained greatest improvement in strength by sets of 5 – 8 per muscle group.
On the track number of sets might be little lower, because running is more holistic than weight lifting and peak forces are higher. The sets should be less than 8 sec. avoiding excess lactic acid production.
Coaches should observe athlete’s training attitude and intensity during power trainings. Low intensity sets and reps are useless!
Q2 – SpeedEndurance.com: Blood analysis seems to be a standard in elite sport in Europe, South Africa, and Australia/New Zealand for screening athletes. In your opinion how should coaches approach this to screen athletes. With injury and illness often occurring with overtraining, what frequency would you have athletes evaluated in order to prevent problems?
Tapani Keränen: Blood analysis is vital, – specifically among endurance athletes. Their energy consumption is at the highest level so enormous that it is good to monitor essential vitamins, iron and red blood cell mass regularly. Regularly, – but how often? Guideline could be ones at the overseason, to get “the baseline values” and then at the end of each training season. Also before and after high altitude training camps, to get information how well athlete responds to high altitude training.
For me hormonal analyses are to complex. But I think the hormonal markers alarms too late. In this I mean than athlete and coach usually already knows that something is wrong well before the hormonal status is at red zone.
In over all blood analysis main function is to monitor athlete’s health, not how much he or she can train more. In this reason the analysis must be done by medical doctor.
Q3 – SpeedEndurance.com: Timo Salpavaara and colleagues used wireless insole sensors to get data on on Javelin, a finish favorite. What do you see in the future with wireless shoe sensors in sport? Force plates are great but often have limits with how many steps it can capture and other problems such as targeting or missing the strike with speed athletes when testing. Do you see this being used more in sport science?
Tapani Keränen: I guess that sensor implement shoes and textiles (www.myonwear.com) are coming. Already now there are sensor football shoes which measures distance and velocity. But it is complete another question how reliable the data is.
I have used pressure insoles in some projects. The big advance compared to force platform is complete freedom of space. Every step or glide is captured from the start to the end. Force measuring can be done in places and sporting events which are far from short force platforms. For example I have used Novel pressure insoles in alpine skiing in very successful way.
The accuracy of pressure insoles is far from force platforms. It is able to measure only perpendicular force, no horizontal or lateral one. I think the systems are still too robust for fast movements, like sprint running, but they are improving all the time.
Q4 – SpeedEndurance.com: Expanding on forces during foot strike, I noticed your study on FORCE PRODUCTION IN THE FIRST FOUR STEPS OF SPRINT RUNNING (download the 2.8 Mb PDF here) saw a an interesting relationship between the steps being having a combination of vertical and horizontal forces. Noted sprint expert Hakan Andersson mentions that the resultant force is highly related to sprint mechanics and doesn’t think this is a holy grail.
Is it wise to pick apart the forces (vertical, horizontal, lateral) with sprinters or is this similar to stride length and frequency, nice to have but not to worry about if you are a coach or athlete. Being someone who works with both coaches and athletes what impact has kinematic and kinetic data provided for the sprinting world.
Tapani Keränen: I agree that force parameters are not at high priority at daily work of athletes and coaches. But applied kinematic and kinetic studies have increased the knowledge of running technique and power.
Force platform is scientific studies measuring tool, giving reliable data from force production moment. Usually those systems are far away from coaching. Usually coaches’ main focus is concentrated to technique and mechanism. This can lead just copying world best athlete’s technique, not applying basic technique to the most optimized way to own athletes performance. They can drive in technique which looks nice, but which is inefficient.
Movements produce force, but without force there are no movements. We have done applied services for some sporting events in which the force measuring is combined to high speed video recording. In many cases horizontal and/or vertical force curve profile explains a lot the efficiency of body parts movements (“athlete’s technique”) during contact phase. This kind feedback is usually enough for coaches, without going any deeper to the force production numbers.
Q5 – SpeedEndurance.com: You monitor power with athletes and spoke at the European Horizontal Jumps and Hurdles Symposium last year (link here) about training speed and power athletes. What can do to profile the development of athletes with the blend of jump tests as well as logs of what they are doing in the weight room.
What tools can coaches use out of the lab to understand how training is helping with the development of power and elastic energy?
Tapani Keränen: Power is more important than strength in sport! Unfortunately you are unable to see it. At the trainings you see strength improvement in lifted weights, lift records, number of successful attempts etc. But you can’t record the velocity of those performances, – although the improvement of velocity is the key factor in the most of sporting events.
How to monitor power? The most important method is to see athlete’s training attitude and intensity during the power trainings! I think box jump, standing long jump and shot throws are good and very practical exercises to evaluate power output. For reactive elasticity I don’t know any practical measurable method.
Luckily some systems from labs have already applied versions for the trainings. I self have used Muscle Lab during weight trainings. It gives extra kick to trainings when athlete is able to see the velocity of the barbell. Infrared mat is also good tool to use during jumping exercises. It is able to measure flight and contact (= force production) time. In this way it motivates athlete and gives some kind estimation to the elasticity.
My guess is that in the near future there’s in the market a lot gym machines implemented velocity meter which measures and gives instant feedback of the movement speed.