Tuesday, October 22, 2013

Cardiovascular Response in Sparring

At my internship today I had some time to kill and grabbed an NSCA journal off the stack on my co-workers desk. It was from May 2008 and had a great study on cardiovascular measurements in karate sparring. Obviously, there are some pretty big differences between karate and most kinds of HEMA, but I don't think the cardiovascular components could be significantly different.

The primary study that I'm going to discuss actually attached VO2max measuring equipment to world class karate athletes while they did some sparring[1].

The results are fairly basic and inline with my own expectations but not necessarily the expectations of many I've talked to about this topic. The study measured heart rate, %VO2max, lactic acid and energy expenditure.

Cardiovascular Capacity

The athletes aerobic capacity i.e. VO2max, was measured first using a standard treadmill test. Then the percentage of that max capacity was measured during sparring. Of note was that the athletes were only at about 40-50% of max while they were sparring. The heart rate was monitored as well and is consistent with anaerobic effort. Another study by the same lab[2] showed that highly technical training like basic striking drills and kata had a lower %VO2max - from a cardiovascular standpoint, they were easier. While sparring drills had a higher %VO2max than actual sparring.

As such we need to include the high intensity sparring drills to get cardiovascular conditioning for fighting.

 

Energy Expenditure

I've heard people talk about how many calories are burned in fighting. And I've thought that the number would actually be pretty low. An assumption I'd made based on RPE and the METs Compendium. And this study does confirm my expectations. Calories were burned at rate of about 5-8 calories per minute*. so for matches that last 2-3 minutes the total calories was be only 10-15. And an entire tournament would range from 50-120 depending on the number of fights and other variables.

* One of those other variables in calorie expenditure is the athlete's weight. The measured values are really most accurate when viewed relative to bodyweight. And the above number of calories is based on 60 kg athletes. The average weight of male fighters at IGX was closer to 90 kg, so we should increase the estimate proportionally.

 

Lactic Acid

All kinds of karate training and sparring increased lactic acid concentrations, but not by amounts that are hard to manage. Interval training will readily adapt the body to managing the clearance of a lactate load. Well trained athletes in one study[2] were able to clear lactic acid back to baseline levels within a few minutes after 70 minutes of training, this despite minimal cardio training as part of their regimen.

 

Intervals in the Fight

The primary study also used video of the fights to time how much time was spent actually fighting versus not actively attacking or defending. The results don't surprise me, but they do emphasize the value of high-intensity interval training (HIIT) relative to long, slow distance (LSD) for cardiovascular conditioning.
  • Average time spent on offense or defense at one time: 0.3 ± 0.1 seconds. 
  • Total time for the entire match
    • 13.3 ± 3.3 sec. for the 2 minute matches
    • 19.4 ± 5.5 sec.for the 3 minute matches
So not a lot. At all. In fact I think the primary value of significant cardio training is that it allows a person to train more. It's not likely to be the determining factor within a single match.

Bibliography

1. Iide, K., Imamura, H., Yoshimura, Y., Yamashita, A., Miyahara, K., Miyamoto, N., & Moriwaki, C. (2008). Physiological Responses of Simulated Karate Sparring Matches in Young Men and Boys. Journal of Strength & Conditioning Research (Lippincott Williams & Wilkins), 22(3), 839–844.

2. IMAMURA, H., YOSHIMURA, Y., NISHIMURA, S., NAKAZAWA, A., NISHIMURA, C., & SHIROTA, T. (1999). Oxygen uptake, heart rate, and blood lactate responses during and following karate training. [Miscellaneous Article]. Medicine & Science in Sports & Exercise February 1999, 31(2), 342–347.

3. Imamura, H., Yoshimura, Y., Nishimura, S., Nakazawa, T., Teshima, K., Nishimura, C., & Miyamoto, N. (2002). Physiological responses during and following karate training in women. / Reponses physiologiques pendant et apres un entrainement de karate chez des athletes feminines. Journal of Sports Medicine & Physical Fitness, 42(4), 431–437.

Tuesday, October 15, 2013

Anti-motion and Isometric Exercises

I've been at my internship for six weeks now. I'd been planning to post each week on some topic within my internship, but I've been kind of swamped (with Iron Gate Exhibition, grad school applications, marathon training, 6am shifts at my internship etc.)

In this post I'd like to expand on the idea proper training for the trunk muscles AKA the "core". Researchers like Stuart McGill emphasize that the primary role of the trunk muscles is to stiffen the torso to prevent motion. This stiffening will transmit force from the lower body to the upper body more efficiently - obviously useful for both striking and grappling. Stiffening the torso will also reduce the stresses on the spine and therefore contribute to a healthy spine and back.

In addition to the trunk exercises that I've discussed before I'd like to add anti-motion exercises to the set of trunk exercises that should be done. And I'd reduce the role of conventional exercises like the weighted crunch.

Unlike McGill I am not convinced that exercises like the crunch need to be eliminated entirely. Firstly, I'll reiterate that I do not recommend a high volume of such training and instead focus on force production with a small volume of weighted exercises. Secondly, there are some limitations to the research that McGill has done which I have not seen addressed. Thirdly, I think McGill generalizes from the physical therapy to the sport training setting in ways that may not be valid.

Specifically, while a relatively sedentary office worker or cashier should focus on excellent posture and limiting spinal motion an athlete definitely needs to move their torso. Just look at the spinal motion, in three planes, of this pitcher. This is good pitching mechanics.
Source: http://www.drivelinebaseball.com/2013/08/16/disconnected-pitching-mechanics-a-good-thing/
So the martial artist will need to have strong spinal and core motion as well. To extend the torso with a lunge, to weave the head to avoid a strike, to cut through the target etc.

Overall a balance must be found in the program between these competing aspects of trunk training. And the balance will be different depending on the person. A new student may be hyper-mobile or have poor posture and so focusing on torso stiffening will benefit them most. Or they could be deconditioned such that the basic isometric exercises will be the most they can handle initially. But with a more advanced athlete the need will include more motion in the balance of exercises, as well as plyos and conditioning like the ropes or heavy bar.

Sample Exercises in the Anti-Motion category include:
Any of the planks and variants, though I will emphasize the value of adding weight or other difficulty to these exercises as building up endurance in these has diminishing returns.
Basic exercises also include the Pallof press and it's variation. An advanced version would be a Push-Pull exercise like this, except with the torso held motionless. Similarly, woodchoppers done with the torso still and reverse woodchoppers.
Anti-motion exercises can also include simpler core exercises like leg lowers, rollouts and deadbugs, when the emphasis is on keeping hips inline with the shoulders, spine neutral and hips stable.