Saturday, February 13, 2016

Overuse Injuries? Or Is It Related To Your Training Load?

Picture by richseow from Flickr
A pair of physiotherapists from the Australian Institute Of Sport (AIS) has suggested that overuse injuries are not caused by how much you train but rather by how your training load changes.

They found that comparing your total workload in the most recent week to the rolling average of the last four weeks of training could predict how likely you were to get injured. The term they used was acute versus chronic training load ratio. They suggest that a ratio above 1.5 is a risk factor for injury.

Consider another study done on a group of elite Australian Rugby League players (St. George Illawarra Dragons) for two seasons.

The players' training load was measured using GPS to track how far they ran during training sessions and games. Interestingly, more training did not seem to correspond to greater injury risk, even with back to back matches with less than a week of recovery. They actually found that players with a high chronic (four week average) workload of running 18.9-22 kilometres were less likely to get injured compared to those who trained less.

However, when they measured acute : chronic load ratio, players with a ratio above 1.6 (increasing training load by 60 % compared to their weekly average over four weeks) were far more likely to get injured. A ratio above 1.2 also put the players at risk, but less than those above 1.6.

Let's say you run 50 km a week consistently but suddenly this week you bump it up to 75 km (acute : chronic ratio of 1.5). You have just increased the chances of injuring yourself.

Or if you normally run 50 km a week but due to illness, work or travel commitments missed some training for a month or two and then decide to run 50 km a week again. That increase in mileage also increases your acute : chronic load ratio. So that is actually a training load error and not an overuse problem.

So if you had to take some time off training and want to resume training again remember to ease back into your training otherwise your acute : chronic training load increases and so will your chances of getting injured.

References

Drew MK and Purdam C (2016). Time To Bin The Trem 'Overuse Injury': Is 'Training Load Error' A More Accurate Term? BJSM. DOI: 10.1136/bjsports-2015-095543.

Hulin BT, Babbett TJ et al (2016). Low Chronic Workload And The Acute:Chronic Workload Ratio Are More Predictive Of Injury Than Between-match Recovery Time: A Two-season Prospective Cohort Study In Elite Rugby League Players. BJSM. DOI: 10.1136/bjsports-2015-095364.

Friday, February 5, 2016

How Effective Is Your Knee Brace?

Assortment of soft knee braces from the Holland Village Guardian
How many of you have seen runners run past with a knee sleeve/ brace on? That's what I always look out for! But that's me and that's what I always do, watching people move and see if there's anything wrong or different.

I've also seen so many of my patients walk in to our clinic with a self prescribed over the counter soft neoprene knee sleeve/ brace. Often, they are asked by the doctors they see to wear a brace.
Often prescribed by doctors
I always ask the patients why they have the sleeve/ brace on. Some will say the brace helps with their pain or it makes their knee feel less wobbly. They usually reply that they feel a little more secure with the sleeve / brace. Most, however are not sure if the sleeve/ brace works.

Let me explain what the differences are. Braces that are stiff and rigid are usually made from plastic, aluminium or carbon fibre. They usually restrict joint movement by physically pressing against the bones of the knee to provide firm external support.

My patient in his rigid knee brace 
While the rigid knee brace can help restrict or limit movement, there is a definite downside  to using them. Have a look at my patient who had a tibial plateau fracture and a partially torn anterior cruciate ligament (ACL).
Check out the rigid brace
See the difference in thigh girth?
Since knee movement is often limited and restricted, the load is often transmitted to the ankle, hip and lower back. Often I end up treating them for the back pain too.

The softer neoprene type sleeves usually will not be able to provide the same mechanical support as they are much softer and do not have any rigid structural support. Neoprene sleeves generally help the wearer by increasing proprioception (or joint position sense) much like the high cut shoes basketball players wear to give themselves more awareness of their ankles to prevent ankle sprains. It is believed that improved proprioception around a knee joint can help stability by improving balance.

However, a 2012 published study of people with knee arthritis found no significant improvements in balance with the use of a neoprene knee sleeve.

There is also very little evidence that knee supports worn prophylactically on healthy knees protect active people against knee injuries.

Granted, knee supports/ braces are usually less expensive or as invasive against knee operations to treat injuries or even arthritis so so people will try them before resorting to surgery.

Some specialized knee supports may help to take pressure off the knee joint while walking and especially during exercise. My patient (in the picture below) intends to use her brace when she goes back to wake boarding and skiing after her injury. Of course I added that proper rehabilitation is important too. Such braces may also be able to help patients with knee arthritis remain active and put off surgery at least for a while.
All ready for action
As explained above, rigid knee braces (but not sleeves) may help after some knee injuries. They are often prescribed by doctors after a patient suffers a torn medial or lateral collateral ligament (LCL). MCL's and LCL's tends to heal fairly well without surgery provided there is no further strain/ injury to the knee for the first 6-8 weeks after the initial injury.

Bracing can be effective when you know what injury you have and the structures involved as a brace can be matched effectively to your needs.
My MCL taping- "Much better than any brace" says my patient
I always prefer to tape compared to using a brace though. As I always say to my patients, I can customize the taping according to their needs and it always fits better than any brace they buy.

So don't just go and buy a sleeve/ brace.


Reference

Collins AT, Blackburn JT et al (2012). The Assessment Of Postural Control With Stochastic Resonance Electrical Stimulation And A Neoprene Knee Sleeve In The Osteoarthritic Knee. Arch Phys Med Rehab. 93(7): 1123.1128. DOI: 10.1016/j.apmr.2011.12.006.

*Big thank you's to all my patients who allowed me to take pictures or sent me pictures.

Friday, January 22, 2016

Is Drinking Milk Or Eating Beef Better For Recovery After Exercise?

Picture by Steve p2008 from Flickr
After your workout, is drinking milk better or eating beef better for recovery? Make a quick guess before you read on.

That was the basic question the authors wanted to find out. The impact of beef and milk as a protein source as a post workout meal.

Here's what made this study unique and interesting.The researchers injected a cow with amino acids specially labelled with a rare isotope of carbon. After that they milked the cow and had it slaughtered to produce meat. The researchers then used the specially labelled milk and meat to feed the subjects in their trial.

This allowed the researchers to track where the protein went through muscle biopsies after the subjects did a strength training session.

The subjects consume 30 grams of protein from either 350 ml of skim milk or 158 grams of ground beef. Rate of protein synthesis (how quickly your body is building new muscle) were as follows.

Picture from Am J of Clinical Nutrition

Milk clearly has the edge two hours after working out. However, after five hours, the rates of protein synthesis were similar.

Other than using the same cow for both milk and beef, this study differs from previous studies as soy protein or whey powder is commonly used in other studies.

The researchers suggested that there may be larger differences between milk and meat if the amount of protein consumed were smaller. 

Personally I would like to know if other kinds of protein such as eggs, chicken or other vegetable proteins will produce different results.


References

Burd NA, Hamer HM et al (2013). Substiatial Differences Between Organ And Muscle Specific Tracer Incorporation Rates In A Lactating Dairy Cow. Plos One. DOI:10.1371/journal.pone.0068109.

Burd NA, Gorissen SH et al (2015). Differences In Postprandial Protein Handling After Beef Compared With Milk Ingestion During Postexercise Recovery: A Randomized Controlled Trial. Am J Clin Nutr. 102(4) 828-836. DOI: 10.3945/ajcn.114.103184.

Saturday, January 16, 2016

Carbohydrates Still The Best Energy Source For Racing

Picture by Erik Stattin from Flick.
Stick to your carbohydrate diet if you want to race well? Or train your body to burn more fat to be more effective in sustaining your effort. Much has been debated over how much carbohydrates and fat we need in our diet to enhance running (or endurance) performance.

Since our bodies can only hold limited amounts of muscle glycogen (or carbohydrates), we usually "hit the wall" after about 20 miles of running. Our bodies store large amounts of fat and if we can utilize the fat stores, we can potentially rely less on carbs.

And fat-adapted running diet is getting popular, especially in the long/ ultra distance running community in an attempt to teach their bodies to use fat (instead of carbs) for fuel.

Prominent exercise physiologist Tim Noakes has suggested that training your body to burn more fat is a more effective way to sustain effort (especially in a long race). Noakes may be right about utilizing fat for ultra distances and we await more research from him.

But carbs may be better if you are running high intensity intervals or racing hard and fast, so says a recently published research.

The researchers studied a group of male competitive runners in four randomized trials running on a treadmill at a speed of 95 per cent of their best half marathon time to exhaustion.

The runners consumed a pre run meal before each trial with different nutritional values. Runners in the first two trials were fed carbs in the form of a jelly. Runners in the next two trials fasted overnight and were given a jelly that looked and tasted the same to the carb group but contained no calories.

Runners in trials two and four were given nicotinic acid which prevented the use of fat stores during testing. This is to test whether blocking the use of fat as a fuel hampered run performance.

Results showed that majority of the time, (83-91 per cent) carbohydrates were the source of primary fuel. The nicotinic acid did not affect the runner's performance or the body's ability to use carbohydrates as fuel. The runners did use a small amount of fat as fuel, but the main source was still carbohydrates.

Your friends or other runners may want to experiment with utilizing more fat to fuel their runs, but this study shows that at least for races up to half marathon, carbohydrates are still best for getting you to the finish line or clocking your personal best timing.


Reference

Lackey JJ, Burke LM et al (2015). Altering Fatty Acid Availability Does Not Impair Prolonged, Continous Running to Fatigue: Evidence For Carbohydrate Dependence. J App Physiol. DOI:10.1152/japplphysiol.00855.2015.

**Note from a runner

A friend who's been on a low carb,  high fat Paleo diet shared that adding carbs back to his diet can be discouraging. For every ounce of carbohydrate he ate after training his body to be used to low carbs, his body stored three ounces of water. His weight shot up quickly.

Wednesday, January 6, 2016

You Should Not Be Heel Striking

Picture by richseow from Flickr
In the picture above, you can see clearly the lead runner and a few others behind him heel striking whilst running. So is heel striking bad?

A group of Danish researchers studied runners who landed on their heels while running, The runners had a personal best time of 17 minutes or slower for 5 km.

In the study, the runners ran 1 km on a track with a force plate at three different speeds. 8 km/ hour (about 12 min/ mile), 11.79 km/ hour (8:20 pace) and 15.78 km/ hour (slightly over 6:00 pace).

The results showed that the total load on the front of the knee actually increases with slower running. This can cause or aggravate anterior (or front) knee pain, also commonly known as runner's knee.

Although the load on the runners' knees was higher on each stride during faster running, the runners took more strides to cover the same distance if they ran slower. As a result, the runners accumulated 80 per cent more load on the front of their knees when they ran at a slower pace.

The results explain why running more mileage (and heel striking) is linked to pain at the front of the knees. This also explains why runners with knee pain who switched to running with minimalist type shoes with the correct technique stopped having knee pain. Note that it has to be correct technique, otherwise the impact can be 7 times greater.

The authors suggest that if you are a heel striker with knee pain you may want to consider running shorter distances at a faster pace to limit the cumulative loads on your knees.

Well, better not heel strike when you run to avoid getting knee pain in the first place.

Reference

Petersen J, Sorensen H et al (2015). Cumulative Loads Increase At The Knee Joint With Slow-speed Running Compared to Faster Running: A Biomechanical Study. J Orth Sports Phy Ther. 45(4): 316-322. DOI: 10. 2519/jospt.2015.5469.

Thursday, December 31, 2015

Fitness Research For 2015

Picture by Elliot Brown from Flickr
As the year draws to a close, I looked back at all the articles I've read and I realise that there were many articles written by research scientists on exercise and brain health this year. 

One of the more persistent themes seems to be that in order to live long, age well and maintain both a nimble and sharp mind we need to be physically active. Many of the new studies demonstrated previously unexplored ways in which exercise helps our brains and minds.

Exercise, usually running seems to increase the number of neurons in our brains and helps sharpen thinking skills and mood as we age.

Fortunately the exercise periods needed seems to be much shorter than we expect

One article I read on brain imaging was really interesting. A group of Japanese researchers found that the brains of fit older men were almost as efficient as the brains of young people. 

The researchers found that the aerobically fit older men's brains used fewer resources during thinking compared to the out of shape men of the same age. This is similar to someone fitter using less energy to perform a physical task compared to someone less fit. 

So at least for me personally, a good reason to keep running regularly to make sure my brain stays sharp.

Another study looked at whether and how weight training and muscles affect the brain. Healthy, older women who completed the year long, twice weekly weight training sessions of light weight training showed fewer and smaller brain lesions in their brain's white matter compared to women of the same age who only completed a stretching/ balance training session or going to the gym once a week.

White matter connects and passes messages to different parts of the brain, which is crucial for memory and thinking.

While I was still training and competing, I used to go to the gym thrice weekly. Since 2009, I haven't at all. Looks like I may have to introduce some weight training/ resistance exercise in the coming new year. 

I do have some heavy tiles/ drain covers in my back garden which I've hauled around before so I don't have to weed the garden so often. Believe me, they're heavy too. I may have my own "nature gym"in my back garden after all ......



So here's wishing all our readers, patients and friends a great year ahead in 2016.

References

Bolandzadeh N, Tam R et al (2015). Resistance Training And White Matter Lesion Progression In Older Women: Exploratory Analysis Of A 12-Month Randomized Controlled Trial. J Am Geriatr Soc, 63(10): pp 2052-2060. DOI: 10.1111/jgs.13644.

Hyodo K, Dan I et al (2015). The Association Between Aerobic Fitness And Cognitive Function In Older Men Mediated By Frontal Lateralization.NeurolImage. 125: pp 289-230. DOI:10.1016/j.neurolimage.2015.09.062.

Tuesday, December 22, 2015

Muscle Wasting Occurs Quickly

Check out the difference in size.
Have a look at my patient's legs in the picture above. See the difference in size? Can you guess how quickly it happened?

My patient fell while skiing in Japan and the doctor there said she tore her medial collateral ligament (MCL). She was prescribed crutches, a huge brace and came back in a wheelchair.

There was definite swelling around her knee and I taped it to reduce the swelling of course and promptly taught her how to walk without the crutches and wheelchair.

2 days. that's how quickly the muscle atrophy took place.

Later an MRI confirmed she tore her MCL as well as her anterior cruciate ligament (ACL) as well.