Friday, February 6, 2015

Geeking Out - Part 3: Estimating Calories Burned

This is the third part (part 1, part 2) of my series on geeking out about your exercise. Geeking out about your exercise isn't necessary. But it can help you become and remain motivated and it can help you achieve your goals.

METs

The simplest way of estimating calories burned in exercise is what's known as METs which stands for metabolic equivalents. At rest a person is at 1 MET. Exercise will be some multiple of this amount.

1 MET is approximately 1 calorie per hour per kilogram of bodyweight. I weigh about 85 kilos right  now, so I burn about 85 calories per hour doing nothing.

Martial arts training, like HEMA, is going to be 5-8 METs. Most of the training is going to be around 6 METs, and using that as a baseline value is a reasonable estimate. While high-intensity training or sparring can get up to 10 METs, this is typically alternated with rest periods so over the course of an hour it will average out to something lower - like 6 METs.

At 6 METs, 1 hour of HEMA would be 85x6 = 510 calories. This is consistent with my own values from my heart rate monitor.

The Compendium(pdf) is a resource that estimates METs for a very wide range of activities. This can then be used to help you estimate calories for all of your exercise and fitness endeavors.

Conclusion

Lot's of different methods exist for estimating calorie expenditure in exercise - apps and online calculators and so on. But for something unusual like HEMA there aren't such resources. As such a heart rate monitor or METs estimate are your best tools.

Friday, January 30, 2015

Geeking Out - Part 2: General Fitness

My last post was about heart rate and calories burned in HEMA training - as determined by a heart rate monitor. In that post I talked about how this informs training for athletic development and performance improvement. Now I'm going to talk about what these numbers say about general fitness, because I know that many folks use HEMA as a part of their approach to general health.

Moderate versus Vigorous Exercise

The basic guidelines for cardiovascular exercise for general health recommend either 60 minutes of vigorous exercise or 150 minutes of moderate exercise per week. Or some combination of the two - basically every minute of vigorous is equivalent to 2.5 minutes of moderate exercise.

Over the course of a 1-2 hour class my typical heart rate was in the moderate exercise range. The only part of my practices that boosted my pulse into the vigorous range is the intense warm-up that is a part of training at Athena School of Arms. However, most groups warm-up is only going to equate to a few minutes of vigorous exercise.

Good motor learning, just like learning anything else, happens best when you are alert and refreshed. Exhausting exercise will impair motor learning. As such, a large amount of vigorous exercise is not appropriate for for a technical training session.

In other words, HEMA training should be moderate exercise, and we shouldn't be pushing ourselves to make a significant part of it vigorous.

Physical Activity Goals

150 minutes per week of HEMA training is a perfectly reasonable objective. I suspect that everyone who isn't already doing that much would like to be able to.

If you are endeavoring to reach a complete program of physical activity for general health and wellness, then your HEMA training, a few times a week, is sufficient for cardiovascular health and fitness. While HEMA training is simultaneously neuromotor exercise - good for balance and agility.

As such you can dedicate remaining available time to strength training and flexibility.

The ACSM guidelines go on to say that greater cardiovascular health benefits are seen at double these amounts. This becomes more time consuming but can be met more easily with the inclusion of vigorous, dedicated cardio work in addition to HEMA training.

Calories Burned

HEMA training burns calories, of course. However, HEMA does not burn calories at an intense rate, as is to be expected from moderate exercise. I will go into details on estimating calories burned in my next post in the series.

Conclusion

HEMA training is a good way to meet both the cardiovascular and neuromotor training goals of a complete approach to physical activity for health. And, well, that's convenient and fun.

Tuesday, January 27, 2015

Geeking Out about Heart Rate

Late last year I got a new heart rate monitor watch. And it let's me geek about my exercise even more. The watch I got was the Polar FT7. Like my last one it uses a strap around the chest to measure heart rate (but this one is cleanable). The chest strap is a good, accurate way to track pulse.

But this watch does more; it tracks pulse throughout the workout and calculates calories burned. I've been using this to track just about all my training and exercise for a few months now. And there are some clear patterns.

What does this mean for HEMA?

Now, I'm not going to pretend that my personal experience and numbers are data. That would contradict some key points that I've made previously. Instead I'll point out that my results show generalizability of other research. A reasonable amount of research has been done on the cardiovascular aspects of martial arts. So far, I have just assumed that our martial art is similar to others in regards to metabolic demand, like here.

My own numbers have been in line with other martial arts studies. This makes sense to me because a 3lb. sword is not going to add much to moving my full bodyweight around.

Heart Rate

It takes time for the body to react to intense exercise and raise the heart rate - this process is mediated by hormonal factors that have to be made, enter the bloodstream and then reach the heart. As such short bursts of high intensity activity will produce only a limited increase in pulse. The muscles being used are therefore primarily acting anaerobically and using their stored glucose (glycogen) and creatine-phosphate for energy.

My heart rate got up to about 155-160 at most. Which is 82-87% of my max. Hitting 90%+ of my max requires much more intense training, like interval sprints.

Most of the time my heart rate hovered around the 125-130 mark. Around 65-70% of my max. But this was only when I bothered to look at my watch, which was usually after doing some particular drill, to see what effect that drill had on my heart rate. One of the great things about the watch is that it gives me a breakdown of how much time I spent above or below 65% of max. And in reality I spend about half or more of my time below that threshold.

The 65% threshold is based on the silly notion of the 'Fat Burning Zone' versus the 'Cardiovascular Fitness Zone'. However, and importantly for exercise planning, these two zones do correspond reasonably well to the definitions of moderate versus vigorous exercise, which I've discussed before. And I'll cover this in more detail for the next post in this series.

So don't expect to get your heart rate up all that high with HEMA training.

Furthermore a quick recovery to baseline is a good trait to watch for. It indicates good cardiovascular fitness and will benefit your ability to do repeated bouts and training. If my pulse was over the line when I looked at my watch, but averaged below that line then I must have been recovering quickly. This is encouraging.

On the flip side, while your pulse doesn't get that high while training it will stay elevated for a long time after you finish. I've continued wearing the strap for a couple hours after exercising a few times specifically to observe this phenomenon. This is when the body goes through the aerobic process of replenishing the resources used while at high intensity - a phenomenon known as Excess Post-exercise Oxgyen Consumption (EPOC). Additionally, this is when the body is literally burning fat as a result of your exercise - the fat is metabolized to fuel the replenishment of your muscles.

Calories

I burned about 10 calories per minute for a typical training session. Some parts of training were higher, and some parts were lower. On the days where I was mostly coaching the rate was about half that. I weigh 85 kg (190 lbs) so your personal expenditures will be different based on your own bodyweight.  I will go into more detail about calculating that (using METs) in another post.

This is in line with the previous research I linked to above about calorie expenditures. Of note is the fact that high-intensity sparring is a higher demand than actual competition.

Overall the calorie demand for HEMA training is comparable to many other common modes of exercise.

How does this inform training?

Make training harder than fighting and fighting will be easier.

Hard sparring sessions can be a component of training max cardiovascular output and recovery. But this must be done intentionally. It is much easier to slowly dial down the intensity of training than to push all out and stay there. And you will do this unconsciously.

Instead I suggest doing flow drills or parry-riposte drills at high intensity for conditioning purposes. Training to exhaustion is bad for technique and strategy so such training should be done with the simplest actions.

And the really intense cardio training needs to be non-HEMA stuff. This is one of the reasons why running is used so extensively in many sports - it can be done with very high intensity and form doesn't break down, and you are not training bad motor patterns for technique.

Really though, we want to keep most training below the threshold for vigorous training because this will facilitate good motor learning. The primary objective of the HEMA class time should be focused around motor learning. The cardio training should be separate - that way each can be done well.

How hard are you training?

This isn't a competition and I'm not saying this to brag or anything. I have visited plenty of schools and talked to plenty more folks about how they train in their classes. And the conclusion is this:

I run the most physically demanding HEMA classes.

I will amend that statement by saying that I believe there are numerous European clubs at a similar level and that I'm comparing myself primarily to US clubs.

This has to do with my objectives for HEMA training. If your club's or your personal objectives are different then do what matches your goals. And I hope that my blog helps you meet your goals.

I'm not saying that my way is only 'good' way or the best way or any other such BS. It meets my goals, though, so it's what I do and how I run my classes.

But this does mean that almost all of a typical groups class time is going to be moderate intensity, as far as cardiovascular response goes. And that just means that the conditioning for performance improvement has to be done separately.

Conclusion

I'm a geek. I obsess about these things. I got one degree in the field and I'm working on another. You don't need to do any of this kind of tracking if you don't want to.

But if you find it helps you meet fitness or performance goals, then by all means, go for it.

Sunday, December 7, 2014

Bad Science

Hot Yoga? Really?

I started reading the Breaking Muscle blog and it's been a mixed bag. But then I saw a post on "3 Ways Hot Yoga May Benefit You". I have a strong aversion to "alternative" practices. By definition alternative means that it's not supported by the science. But this post is about some published scientific studies on the potential benefits of hot yoga.

I have no problem with yoga - when it's benefits are accurately described. Yoga can be a perfectly good way to meet the flexibility aspects of a complete physical activity program.

I just get all uppity when people say it's great for everything. (And I get that way when anything is called great for everything.)

Some of you may be wondering why I'm going to go on this rant about one study of hot yoga, when this is supposed to be a HEMA training blog. The point is to demonstrate the skills necessary to be a good consumer of science. To learn appropriate caution when encountering science-y sounding fitness claims on the internet.

So, is Hot Yoga good for Fitness?

Well, this blog post went over one study that looked at strength and cardiovascular measures and another for cardiometabolic risk factors. And both studies are flawed. And the results of both studies are overstated. This is a common problem with reporting on science - the results are overstated, and generalized beyond the scope of the study. Furthermore making strong claims about anything based on one study is bad science.

The basic prescriptions for how to improve strength and cardiovascular ability are based on hundreds of studies. So before it can be claimed that yoga improves other fitness components we should have a good evidence base. Not. Just. One. Study.

Bikram Yoga and Physical Fitness in Healthy Young Adults


This study appeared in the Journal of Strength and Conditioning Research. It's not terrible. But it's results are weak and then exaggerated. The study looked at just 21 people. Well, it started with 32 but 11 dropped out of the hot yoga group. That's a big red flag right there! 50% dropout from only hte experimental group severely effects the outcome of a study. The subjects were divided into two groups: hot yoga and control. The hot yoga group was allocated twice as many people, because they expected a high number of dropouts. So, they knew in advance that there would be a problem and went ahead anyways. Not encouraging.

Why did people dropout? We are told that some had scheduling issues and others were "dissatisfied". Quite a number of studies are published in this field without such high dropout rates from scheduling issues. So I think it's much more likely that half of their experimental group just couldn't take the hot yoga program - which is done with the thermostat set extra high and plenty of humidity to boot.

If only the strong survive your study then that will skew the results towards a positive outcome. We don't end up measuring the people who are struggling.

And since they knew in advance that the program was so hellish that half of the subjects (who are volunteers getting paid to do yoga) would dropout you have to wonder whether or not any benefit is going to be worth it.

The control group was doing no exercise and the subjects were all sedentary to start with. In such a group of people any exercise will show improvement. So comparing four and a half hours of exercise a week to no exercise isn't a test of hot yoga versus other methods. It's a test of whether or not it's better than literally nothing.

So what were the results? Unimpressive. Two strength measures were used: grip strength and isometric deadlift. The grip strength showed no improvement, but there aren't any gripping activities in Bikram so that's not surprising. The other test showed some modest improvement*. But it's an isometric test following an isometric program. It's not going to translate well into real world performance and health measures. Since in the real world you don't just pull on a chain attached to the floor, you move.

* Or it didn't because they used shady statistics. I'm not certain about this. But they used a statistical measure that is not common in this field. And they also reported the common measure, and that one came up negative. However, this other test (group x time point comparison) did show statistical significance. Anytime I see a brand new test I get curious - I asked my stats professor about this. So it seems like the test is legit for this purpose. But did the researchers pick this because the regular test didn't support their hypothesis? I don't know.

Flexibility: They measured two flexibility components, low back/hamstring, with a sit-and-reach; and shoulder flexibility. Unsurprisingly, the yoga training produced substantial increases in the sit-and-reach test. But that measure of flexibility is not well correlated with either performance measures or health/fitness measures (like low back pain). So, who cares if that improved?

They also measured active shoulder range of motion. The test involves laying face down and holding a stick overhead. Then you lift the stick as high off the mat as you can. This measure improved as well. But not by a huge amount. Given some of the postures in Bikram this result is not surprising either.

Body Composition: The changes here were slight to none. And we get to see the researchers use the phrase, "trended towards significance". Ha! Individual p-values do not have a trend. When most of the p-values you get in a category are not significant, then you definitely don't have a trend. This phrase is researcher bunk for, "um, we didn't get a positive result, but, we . . uh . . . almost got one."

So, 4.5 hours of light exercise a week barely beat sitting around for improvements in body composition (weight, waist-to-hip ratio, body fat % and lead body mass) - not exactly surprising. Nor noteworthy. Only one actually significant result out of four tested also smells a bit like a fishing expedition.

Cardiorespiratory: I don't know why the researchers thought that standing still in various poses for 90 minutes would have improved cardiovascular health. Maybe because it was so hot that the heart had to work extra hard to keep the body cooled? Suffice it to say there was no improvement in blood pressure or aerobic capacity.

Why is it so Damned HOT in Here?

Seriously? No attempt is made by the authors to explain why they thought that yoga in a super hot, humid room would be better than regular, comfortable room yoga. And none of the things they measured seemed to be related to the heat. None of the minor benefits that were seen can be attributed to the heat since they were all similar to what you would expect from a regular yoga program.

Why do I care, though? Because hot yoga is an unnecessary risk for heat injury. It's hot enough in that room to mess you up. There's a reason that half people in the program decided not to finish it.

A nice description of the risks is given here, and from the same website to boot.

And, no, hot yoga does not sweat toxins out of the body! That's just not a thing. Human physiology doesn't work that way. Sweat glands only selectively excrete specific substances - they don't sieve your bloodstream and leak out whatever they find.

In summary:
Higher risk than regular yoga or exercise.
Minimal benefits that can just as easily be achieved cheaper and comfier.

Conclusion: not worth it.

But why did I rip so hard into this one study? Because proper science means that the more outlandish the claim the better the evidence required. Saying that a single exercise mode will help everything while in an excessively hot room is an extraordinary claim. So it requires extraordinary evidence. This study fails to meet that bar.

The bibliography:
Tracy, B. L., & Hart, C. E. F. (2013). Bikram Yoga Training and Physical Fitness in Healthy Young Adults: Journal of Strength and Conditioning Research, 27(3), 822–830. doi:10.1519/JSC.0b013e31825c340f

Yoga for Cardiovascular Risk

The same blog entry also talks about a study looking at cardiometabolic risk factors. That is risk for heart attacks, strokes and diabetes.

You've got to be kidding me. Light intensity exercise like this has no plausible mechanism for improving any of the things they measured.

And this can't be taken seriously. We can see that with information contained within the citation alone. It's from the Journal of  Alternative and Complementary Medicine, which makes the Quackwatch list of Non-recommended Periodicals. This journal has an impact factor of 1.5 which means that most scientists won't cite stuff from it. Neither of these pieces of information is perfect in determining quality, but they show a trend.

The actual study continues the trend.
  • No control group. Seriously, this journal published a study without a control group. Why?
  • A large number of disparate measures are used. I feel like they just used everything they had in their lab.
  • Paradoxical results. One group improved in one measure the other group did not. But the other group improved in something else, unrelated, which the first group also did not improve.
This is not a good study. It should be ignored. Instead of cherry-picking weak studies that show what you want if you squint, the blogger should have looked for good research and clear patterns in the literature.

Yoga for Mental Health

There was one other study in the blog post that I'm ripping on. It was on mental health improvements. However, that exercise and a meditative practice improved some mental measures is not noteworthy. Of course it did. And that's a good thing. If you want to do yoga for the meditative aspect then more power to you.

Conclusion

We have three weak studies of hot yoga. None of them even attempts to address the core issue: does hot yoga have any benefit over regular yoga? Read any text on exercise, personal training, sports medicine etc. and you will have a section on how high heat and humidity is dangerous. How training in those conditions should be avoided, and when it can't be avoided you have to take additional precautions to keep people safe. 90 minutes straight of activity in that heat would not be considered safe in any other context.

Only in alternative practices would this even be considered. Take something known to be dangerous and then declare it superior. Then don't bother testing it. Remember, none of these studies compared regular temperature yoga to hot yoga.

This is the kind of research that's considered good enough for alternative medicine. And it's why these kinds of claims must be scrutinized more closely.

(/rant)

Wednesday, December 3, 2014

Fitness Experts at the Doctor's Office

Continuing to talk about how to improve the healthcare system (like I did here) there is another clear place for primary care to improve - exercise and fitness advice at the doctor's office.

Too many times I have had friends complain, legitimately, that the doctor just tells them to get more exercise and says nothing more about the topic. They just hope that this is enough. Or maybe there is a pamphlet. 

Exercise is too big a topic for most people to just jump right in because their doctor said so. And those who do are quite likely to overdo it, injure themselves and then stop exercising because last time they got hurt. (Commonly this is thinking that you have to do 30 minutes of cardio as a minimum; which is too much as a starting point for most folks -  I talk more about this here.)

Furthermore, most doctor's don't know what's involved in a complete approach to physical activity for health. Doing a lot of running, without any kind of strength training can cause injury and does little for some of the common problems of aging like muscle loss and osteoporosis. As I've said before, I don't fault the doctor's for not knowing everything. But it is a reason for primary care to have some fitness and/or PT component attached.

What people need is someone who can guide them through getting started with an exercise program. Doctors' offices are already incorporating dietitian's to provide nutrition advice, so let's add the other half of healthy living: physical activity. 

The emphasis of such a program should be on behavior change. A topic well-covered in my undergrad program. Basic exercise advice is easy. Helping a person make long-term changes to their life is different. It requires a different skill set. It takes a lot more than just a personal trainer certification.

UMass Boston's major in Exercise & Health Sciences has a mandatory track of classes in behavior change. Graduates from this program would be the ideal kind of person to add to the staff at a doctor's office. Because this person doesn't get paid like an MD they can spend more time with each patient. They would be dedicated to just one topic when they meet with the patient, unlike an MD doing a physical which has to cover every organ system of the body.

I'm going to see what I can do about just this as part of my time at the Institute of Health Professions. Health promotion and community outreach is a part of our the program at IHP. Perhaps I'll get to run a small pilot program. I don't know. 

Sunday, November 30, 2014

Balance Training & Agility

The approaches I commonly see for training 'balance' for HEMA are a problem. The problem is lack of specificity. Single-leg balance and yoga poses are encouraged. Long holds in various stances are recommended. Even things like wobble boards and BOSU's sometime are suggested.


Don't Do This!
(updated when this topic came up on the HEMA Alliance forum)
 
These all fail to be good choices for a simple reason: they are based on the idea that balance is a singular trait that you can improve. Like your Dexterity score in D&D. The human body just doesn't work that way. Our wires are not set-up that way.

Balance is always task specific. The best programs for preventing falls in the elderly aren't yoga and single-leg standing. They are obstacle courses. Walk and deal with obstacles - 6 inch high hurdles and the like in this situation - and that makes a person less likely to fall while walking.

Avoiding falling is also about power. When you are off-balance it does not take a 30 second sustained low-intensity contraction to right yourself. It takes a brief high-intensity action. And this is another way that strength training benefits HEMA and long-term human health and wellness.

And in HEMA the kinds of situations that lead to falls are when you are almost always when you are moving and moving fast.

So really, balance for HEMA is agility training.

I write this now because of a recent post over at the HEMAists. But I'm not picking on them. There is good stuff there too, just scroll down to see the part I liked. I've encountered similar suggestions in many places.

One guy on the Alliance forum FB page suggested holding a lunge position with arms extended out to the side for 60 seconds. He said I should try it to see how hard it is. But how hard that would be is irrelevant. In fencing I will never hold the end of a lunge that long. And the difference is an order of magnitude. And I'll never hold my arms out to the side that long either.

So the fact that it is hard tells us nothing about whether or not it is relevant to fighting. These are separate characteristics being measured.

How do we train 'balance' for HEMA?

We do it with agility drills. Exercises like ladder (or sword) drills, dots, cones, rings and hurdles. (Nah, I don't get any money from these folks. I just like their products (however their are frequently cheaper options available.))

I'll be talking about agility drills some more in the next few weeks. And I've talked about it a bit before.

Balance v. Stability

Balance and stability don't mean the same thing. This is me being pedantic because I'm professionally a nerd on this topic. But I think the difference is relevant and I'll provide an example in a moment.

In exercise science we use the terms to mean:
  • Balance -  keeping the whole body upright or in position
  • Stability - a characteristic of an individual joint being capable of holding a position
I'm not thrilled with the balance exercises from that HEMAists article. But I do like the stability exercises at the bottom. The exercise is a plank with a punch out, then rotate to a side plank and punch up. This exercise doesn't train balance. It trains maintaining a stable spine while moving around it. It's another way to do dynamic core work. I'm starting my guys on this exercise tomorrow.

I would make one addition about the exercise as described. An easier version is to start with the down arm on the elbow. A lot of people will need to start there.

Conclusion

Think hard about what specificity means before adding in new, neat  exercises.

P.S. I've got a sale going on right now for in-person training.