Tuesday, August 28, 2007

SBR and AHM, 26th August 2007

Army Half Marathon 2007

Have had a long lay off from racing after Chicago last October, due to BAD ITB problems. Thankfully, have had a few things occur that have made it right recently. 1) Saw my chiro, which isolated the problem, 2) Saw a sports medicine specialist, who got my foot type checked correctly and recommended the right shoes, and 3) Attended a sports injury talk at CGH, which finally gave me an insight to what the whole issue was.

Suitably prepared, I targeted the AHM as my first competitive run for the year, despite a less than good impression of the route and organisation last time out. Also this time, no pussyfooting and making this merely an LSD training session. If I were going to pay money and get up at 4 in the morning, it had better be worth it!

The difference in my training this time was a more focussed attitude on quality of training as opposed to quantity. As long as I got 1 LSD and 1 tempo/hill, and one or two "fitness maintainers" in a week, I was going to be happy. I believe this was very effective for me.

Week before the race, struck down with flu. Had one 12 clicker in at the start of the week before the flu got bad, and was simply laid up for the rest of the week till Friday. Snuck out for a light 4 clicker on Friday evening. Total mileage for the week....16km! Yuks!

Race Day. Flu lifted, legs feeling bouncy. This was going to be a great day! Indeed, it started well. Timed the toilet visits well, got myself to really near the front. Horn blows, away we go. Running by myself (which I prefer), I am doing 5:05 pace for the first 2km, it is too fast and I deliberately slow it down. No choke point going into ECP this year, which was a real morale buster last time. Hit the upslope, then saw the 2:30 pacer, running at close to sub-2 pace! Poor fellow, must have kenna arrowed by his CO or something. Distance reading on Polar is underestimating a little, its ok, this round foot pod calibration is a little off, as long as its by fixed factor, I can recalculate mentally. Down the bridge and I arrive at the 7km water point, my first stop. Typically, I would stop every 4-5km during training. This time out, with cool weather and good prior hydration, I was going to try a 2-stop strategy. So far so good, looking at a sub-2hr finish.

Turn into Fort road, heading into the parkway. Are those runners coming back down the other way ALREADY??!! Oh my Goodness!! Humbling to say the least. Nevertheless, in the zone now and chugging along. At around 10km, toilet stop at one of those park toilets. Now if you ever have to stop in the middle of run to urinate, BE CAREFUL! Being the highly trained athlete you are, your vagal tone is mighty high. Stopping suddenly to urinate may drop your heart rate and BP drastically.

Ok, more than halfway, still on course and feeling good. At 15 km, 2nd and final water stop. Sun up for a bit already and the air is warming up. A little later, foot pod goes wonky. Grrrrr........not the first time it has happened during a race! Garmin, here I come. Anyhow, pace info not really important anymore, run according to heart rate. Had been chugging along at 5:40 pace, HRM now going at 160. Told myself I will not allow it to get higher than 170, no matter what. Too much risk for an old ticker to bear. Little did I realise the poignancy of that thought at that time. Push for the last 2 km, finished at 1:59 according to stop watch. PB for the half, and plenty happy for it. It was a nice run. Route was good, no choke points, no traffic interruptions, plenty of water/isotonic stops. Well down Army.

Took a couple of bananas, had my drink, and headed straight for the train station. EZ-link card and cash is in my arm pouch, hate the idea of bag check (good decision, as it turned out). Home by 8.30, gave my medal to the elder boy (he's 4), and still got to church only a little late.

Had a late breakfast with church friends later. "How was your morning?", they asked........

"It was GREEEAAATTT!"

Monday, August 27, 2007

Aetiology of Muscular Cramps in Marathon Runners

Review of article outlining Current State of Knowledge for Muscle Cramps after Long Distance Running

Martin P. Schwellnus; Sports Med 2007; 37 (4-5): 364-367


This is not a novel article as such, but more a review of other articles, and therefore is short on data. So, take it for what it is.

EAMC is the commonly used term, or, "exercise associated muscular contraction", which the author expands and adds qualifications to become "a painful spasmodic involuntary contraction of skeletal muscle that occurs during or after exercise."

Two of the more commonly hypothesised aetiological causes of "muscle cramps" have been "electrolyte imbalance" and "dehydration". He explains why electrolyte imbalance, although implicated in severe enough cases, with generalised muscle spasm, is unlikely to be the cause in localised muscle cramps of the type seen in sports or distance running. Likewise, he describes a
number of studies that seemingly disprove dehydration as a causative agent.

The rest of the article puts forth the position that "muscle fatigue" is the chief cause of EAMC. It is quite technical so I will spare the details. Suffice to say, lack of details notwithstanding, I find this hypothesis more credible than others, and bears out my own personal experience.

My editorial;
I have had my share of muscle cramps in my younger days from other sports like soccer and tennis. Invariably, they occurred after prolonged sessions in either sport. When you are young you think you are invincible and will push well past your limit. To date, have not had any cramps while training or racing long distance running. This of course is occurring only recently for me, in my more prudent, middle aged state, when I rarely push so hard outside my envelope. I did, during my very first marathon, feel a cramp coming on in my right quad at about 35km, a distance I have not reached before in training. Having been the "beneficiary" of previous cramps, I backed off the speed and ended up run-walk the rest of the way.

I believe, hydration, electrolyte top-up and so forth as useful insofar as they put off the point when fatigue sets in. But at the end of the day, it would appear that your exertions on the day, in relation to your training levels, will determine how quickly and badly you fatigue, and hence how prone you will be to cramping.

Tuesday, August 14, 2007

ACL Reconstruction Experience

Posted as a contribution to sgrunners forum:

I had a complete tear of my right ACL in 1999, confirmed on MRI and clinical examination. Injury incurred during a soccer game. Reconstruction done 8 months later, and during arthroscope, was confirmed that ligament was completely torn

A few points;

1) Knee stability with ACL tear.

The ACL is one of the ligaments of the knee that stabilises the joint. Specifically, it restrains the femur (thigh bone) from sliding backwards on top of the tibia (shin bone), and vice-versa. It is [u]actually POSSIBLE to continue running safely [/u]with a completely torn ACL. My ortho surgeon suggested as much, and 2 weeks after the injury, I was back to normal running >5K with little problem. The point is that if you have decent muscle strength, sub-sprint running on an even surface does not stress knee stability that much. If you do want to play sports, however, it is a different story. For games like soccer, tennis, and the like, changes in direction are the norm. If your ACL is torn, the instability could lead to further knee injury.

2) Further and associated injuries with ACL tear.

Very often, the force required to cause an ACL to rupture is huge, and other knee structures get injured as well, most commonly, the meniscus. Do check out if you have associate meniscal injuries, the MRI should help. Fortunately, I did not. With increased instability, the risk of incurring a meniscal injury, even if you did not originally have one, is now quite great. This was the main reason I decided to go for a recon, because I had wished to continue with other sports. If all the exercise you did were swimming, biking and running on a flat surface, I'd say you could get away WITHOUT doing a recon, provided you had good muscles already providing ancillary stability.

3) Cause of the tear.

Fatigue Fatigue Fatigue. As you get tired, your start losing attention and your muscles are less able to cope with stress and loads. The injury occurred during a competition and I was playing my 3rd game of the morning, about 100 minutes of game time. As I leapt to evade a tackle, when I landed standing there was a loud crack and my knee gave way. Basically the hamstrings were just too tired to help take the force of the landing and the entire weight bore down on the ACL, causing the rupture. Take care of the body and don't overexercise!

4) Consequences of an ACL recon.

Not nice! You could be walking in about 3-4 days, but muscles withered away and fully took me 6 months to get the bulk up. But there would always be a deficit compared to the normal side, up to 10% less strength or more. Definitely lost explosive strength on that leg. However, got good stability and now back to racquet sports, but no serious soccer, just kick-about with kids.

Thursday, August 9, 2007

New Route from near home to Singapore Botanical Gardens

Tried a new route this morning. Mostly pavement and cool in the morning.

Wednesday, August 8, 2007

To Run or Not to Run. The Contradiction of Cardiac Risk in Exercise

My contribution to a discussion in the SGRunners forum on the dilemma facing wannabe runners with risk factors for cardiac disease.

Given the dramatic nature of a young and apparently fit sportsperson collapsing after a race, it is understandable that the lay public may draw the wrong conclusions and become leery of exercise. Isn't exercise supposed to be good for your heart? Why are all these "fit" men running marathons and racing triathlons keeling over then? How to reconcile the apparent contradiction?

It is probably best described in the sentence below, excerpted from the article cited in the next paragraph.

"Physical exercise reduces the incidence of atherosclerotic heart disease by managing atherosclerotic risk factors such as a high heart rate and hypertension(1). Vigorous physical activity such as endurance exercise increases the risk for myocardial infarction and sudden cardiac death in patients with diagnosed and latent heart disease(2)."
Am J Cardiol. 2007 Mar 15;99(6):849-51. Epub 2007 Jan 26
Major adverse cardiac events during endurance sports. Belonje A, Nangrahary M, de Swart H, Umans V. Department of Cardiology, Medical Center Alkmaar, Alkmaar, The Netherlands.

In other words, it would appear that in the long term, exercise is a useful, and indeed, essential strategy for folk who are at risk for cardiac events to control their risk factors. A proper exercise regime has been shown to lower lipids, blood pressure, and allow the heart muscle to withstand a heart attack better. This is not to say the risk is completely eliminated. As has been amply demonstrated, extraordinarily fit folk can also be struck down. Sometimes you just can't escape genetics. It is noteworthy that the article ends with the following paragraph;

"The incidence of MACEs in well-trained marathon athletes is very low. In our series, it occurred in only 4 of 62,862 participants, and none of these participants died. All events occurred shortly after or just before the completion of the races. A rapidly available manual defibrillator is among the lifesaving medical equipment that should be on site at all major sporting events."

In the 2 references quoted above, the first describes the health benefits of long term exercise;

(1) Exercise and physical activity in the prevention and treatment of atherosclerotic cardiovascular disease. Thompson PD. Arterioscler Thromb Vasc Biol. 2003 Aug 1;23(8):1319-21.

Exerpts describe reduced blood pressure;

"A meta-analysis of 44 randomized controlled trials including 2674 participants6 demonstrated average reductions in systolic and diastolic blood pressure of 2.6 and 1.8 mm Hg in normotensive subjects and 7.4 and 5.8 mm Hg in hypertensive subjects, respectively."

delayed/reduced onset of type2 diabetes;

"In the DPP, an average 4-kg decrease in body weight and a 593-kcal increase in weekly energy expenditure (approximately 6 miles of walking) reduced the onset of type II diabetes in individuals at high risk for this disease by 58% compared with usual care. The lifestyle intervention was also significantly more powerful than the 31% reduction in the onset of diabetes produced by metformin 850 mg taken twice daily."

amongst other benefits. If you have already had a cardiac event, exercise plays a critical role in rehab;

""Total mortality decreased 27% (P[1]0.05) with the exercise only intervention, but only 13% (P NS) with the more comprehensive rehabilitation programs suggesting that the exercise training is critically important for the beneficial effect. Cardiac mortality was reduced 31% (P[1]0.05) and 26% (P[1]0.05) for the exercise only and comprehensive programs, respectively."


So, lots of pluses. What are the downsides.

Thompson PD. The cardiovascular complications of vigorous physical activity. Arch Intern Med 1996;156:2297–2302.

"The predominant causes of exercise-related cardiovascular complications are congenital abnormalities in young subjects and atherosclerotic coronary disease in adults. The absolute incidence of exercise deaths is low. Only approximately 0.75 and 0.13 per 100,000 young male and female athletes and 6 per 100,000 middle-aged men die during exertion per year. Nevertheless, exercise does acutely and transiently increase the risk of cardiac events. CONCLUSIONS: Routine cardiovascular testing to prevent exercise events (echocardiography in the young and exercise testing in adults) has limited usefulness because of the rarity of such events, the cost of screening, and poor predictive accuracy of exercise testing for exercise events. Physicians should (1) perform routine screening and cardiac auscultation in young athletes; (2) carefully evaluate exercise-induced symptoms; and (3) ensure that adults know the symptoms of cardiac ischemia."

In a nutshell, exercise is good for you, just be careful when doing it!

Cheers.





Monday, August 6, 2007

7 Reasons Why a Low Carb Diet is Wrong!

Reproduced from Sports Performance Bulletin (6 Aug 07):

Sports Performance Bulletin nutritional expert, Charles Remington, explains the health problems you may experience with a low carbohydrate diet.
Obesity is now the second leading cause of preventable deaths in America. The medical community used to see it as simply the result of poor eating habits or a lack of will power but now they are beginning to define obesity as a disease that poses a dire threat to our public health. Low carbohydrate diets have become popular as the solution in our battle to lose weight. Unfortunately the human body is equipped to use carbohydrate as its primary source of fuel.
Sadly the latest low carbohydrate fad diets are not the fuel the human body was designed to run on. Low carbohydrate diets can cause several health concerns over time. Here are my top seven.


1. Poor exercise performance and recovery

Carbohydrates are the primary fuel for your muscles and brain. Eating a low carbohydrate diet prevents proper maintenance of muscle and liver glycogen (storage form of carbohydrate and water), thus decreasing muscle performance and increasing muscle fatigue. ATP is the main source of energy for all muscle contraction.When a muscle is used, a chemical reaction breaks down ATP to produce energy. There is only enough ATP stored in the muscle for a few contractions. More ATP is needed. There are three enzyme systems that can create more ATP. The three sources of ATP for muscle contraction are carbohydrates, fatty acids and amino acid proteins. Carbohydrates metabolise efficiently and are therefore used first. If carbohydrates are not available, your muscles metabolise fatty acids and amino acids as secondary sources of ATP. These secondary sources are not efficient, which consequently cause your strength and endurance to drop drastically. It needs to be customised to your amount of muscle and exercise schedule. High-fibre, low-glycaemic (turn into blood sugar slowly) carbohydrates can provide up to 50% of your calories, which will lead to increases in strength and muscle endurance.

2. Gout

Gout is a form of arthritis that occurs when excessive uric acid levels start to crystallise in joints, leading to pain and inflammation. Uric acid is a waste product in the liver's metabolism of protein. Excessive amounts of protein may lead to an inability to eliminate uric acid. I would recommend you should not exceed 1 to 1.25 grams of protein per lean pound of body weight.

3. Kidney stones

Kidney stones are hard masses that form in the kidneys when uric acid or calcium oxalate crystallise and over time form stones. Insoluble fibre found only in carbohydrates reduces the absorption of calcium, which cause urinary calcium levels to drop thereby preventing the formation of kidney stone. I would recommend the consumption of 30 or more grams of fibre daily. This is not attainable on low carbohydrate diets.

4. Constipation and poor intestinal health

To maintain good intestinal health our bodies require 30 or more grams of fibre daily. Fibre is divided into two types, soluble and insoluble. Insoluble fibre is vital in formation of stools and decreases the time process of waste elimination. Low carbohydrate diets are too low in insoluble fibre and increase risk of constipation. Poor transit time of waste material increases risk of certain colon cancers. Insoluble fibres prevent the build-up of mucus on intestinal walls which lead to poorabsorption of nutrients into the body. Low carbohydrate diets are inadequate to maintain good intestinal wall health. I would recommend you use whole grains, oats, beans, fruits and vegetable which are rich in soluble and insoluble fibre. This lowers the risk for constipation, haemorrhoids, irritable bowel, diverticulitis, Crohn's disease, and colon cancers.

5. Rise in cholesterol levels and an increased risk of heart disease

The risk of heart disease increases on low carbohydrate, low fibre diets. These diets promote excessive amounts of animal protein, cholesterol and saturated fat. Exuberant amounts of protein increase homocysteine, which is a by-product of the amino acid methionine. Many experts believe that high homocysteine levels have many toxic effects which lead to increase risk of heart disease and hardening of arteries. Low carbohydrate, low fibre diets reduce the absorption and eliminationof digestive bile in the intestines. Digestive bile is produced in the liver from cholesterol. A decrease in digestive bile production raises blood serum cholesterol levels which increases the risk of heart disease. Unlike low carbohydrate diets I would promote a nutritional balance providing 30% protein, 50% high fibre carbohydrates and 20% fat.

6. Osteoporosis

Osteoporosis is the reduction of bone density, due to the loss of calcium over long periods of time. Several dietary factors increase the risk of osteoporosis. When dietary protein reaches excessive levels, so does the loss of calcium in the urine. Most studies show that a life-long high protein diet results in an increase of obsteoporosis. Poor intestinal health due to low fibre diets cause inadequate absorption of calcium in intestines contributing to poor bone formation. This would suggest that no low carbohydrate diets can become a life long lifestyle of eating. This is only one of many reasons why low carbohydrate diets provide poor long term weight control. Interestingly, a diet too low in protein can also increase risk of osteoporosis. There is no one size fits all when managing our weight so it has to be customised to the individual, providing the right balance of protein, carbohydrate and fat.

7. Loss of muscle and reduction of metabolism

Any diet that applies the restriction of calories less than the body's daily requirements over long periods of time will result in the loss of lean muscle tissue and a decrease in the metabolism. All low carbohydrate diets are focused solely on weight loss. The loss of fat comes at a high cost, which is the loss of lean muscle. The loss of muscle reduces the resting metabolic rate, which is the major cause for rebound weight gain. Research shows 95% of all dieters will regain that weight . We do not fail at diets - diets fail us! The secret is not to try to lose fat every day as this will result in losing muscle and reducing metabolism.
Final thoughtsLong-term success in managing weight starts with the right approach. If you are overweight, the real problem is that you have too much body fat for how much muscle you possess. A body composition solution is needed, not just a weight loss diet. Your goal should be to lose fat without losing muscle or sacrificing your health in the process. To maintain your results your eating habits must develop life-long character. Low carbohydrate diets provide initial weight loss, but at the high cost of losing muscle and reducing metabolism. They are inadequate sources of fuel to support exercise activity, which is vital in maintaining good health. The risks to your health long term make low carbohydrate diets poor solutions for life-long weight management.

Running for My Life

Greetings,
its been an amazing 2 years for me as of today (Aug 6th 2007). Got kickstarted on running again, got my Polar HRM, and actually hit the road with some seriousness. On National Day 2005, actually got up in the morning, something I had not done since NS, and did 6 km, the longest distance I have run in years and years.

Over the ensuing months, lost 12 kg, completed my first 10km (SCSM 2005), and signed up for the 2006 Virginia Beach Marathon. To my knowledge, I was the only Singaporean at the race, which I completed in 4:32. Next stop, Chicago, done and dusted at 4:28. My wife had her own marathon up and down the Magnificent Mile.

Running has been an incredible change agent for me. If you are a doubter and reading this for the first time, don't wait anymore. Buy a pair of shoes and JUST DO IT!

Bruce! Bruce! Thy protocol does hurt!

With all the publicity around young fit guys keeling over, I really thought it would be a good idea to get myself checked out as I ramped up my mileage. The ECG stress test was an optional part to my biennial company health screen anyhow, which was due.

On the day, had checked in at the medical centre, had blood drawn, then waited at the cardiology centre. Shortly after, into the test room. There was a basic looking treadmill in a corner, hooked up to a computer, and an ECG machine with attendant wires. Shirt off, shoes on, wires stuck on, and off we went.......

.....and I thought I was in pretty good shape, Good Grief! Let me warn you, if you ain't trained in running, this is NOT an easy test.

Started off easy enough, but once I got to stage 3, I knew I was in trouble. By stage 4, I could barely keep on the treadmill. Don't let the slow speed fool ya, the 16% gradient by that stage is a killer. I stopped after a minute and a half at stage 4. I was near maximum predicted HR, sweating like a pig, and glutes and calves burning. Anyhow, as far as I could make out, seemed not to have any significant findings on the ECG tracing, and no symptoms to boot.

So all set! AHM in a 3 weeks and SCSM on the horizon. God keep me safe in my training.

For those interested in what the Bruce Protocol Stress Test is, here is one link -->

http://www.topendsports.com/testing/tests/bruce.htm