Heat Acclimatization Can help Exercise Performance

Other than the heavy rain the last two days, it's been very hot recently. I used to love training and racing in the heat. Living in sunny and super humid Singapore meant that we're used to such conditions.

I'll often train in the hottest part of the day so that when race day came, whatever sweltering conditions encountered (on race morning) will seem like a breeze. There was a year (2001) when the Osim Singapore Triathlon was held in Sentosa and it was 38 degrees Celsius on race day and I used that advantage to finish 3rd overall behind Dimitry Gagg (former World Triathlon Champion in 1999).

On the podium with Dimitry Gagg in 2001

Turns out I may have been right in getting an edge over my competitors. And you can use that to your advantage too.

Heat is now hot! This shift towards heat training has been trending for the past few years. From running marathons to even climbing mountains, athletes around the world have been trying to get potential performance benefits of heat training.

Many of these heat studies started because of the 2008 Beijing Olympics. Many runners were preparing for the sweltering conditions and that lead to a whole lot more research done on heat acclimatization.

There are even studies of using heat therapy to fight heart disease and repair muscles.

Most heat acclimatization protocols help athletes perform better in the heat. This includes lowering core body temperatures, increasing perspiration rates and increasing volume of blood.

And what if after all that training in the heat race day wasn't hot? What if race day turns out to be as cold as the 2018 Boston marathon?

Fret not, results of a study (Lorenzo et al, 2010) on whether being well adapted to heat might affect your performance in cool conditions put that worry to rest. Scientists had cyclists train for ten days in 41 degrees Celsius (105.8 degrees Fahrenheit). Their VO2 max improved by 5 percent while their one-hour time trialing performance improved by 6 percent! This was when they were tested at 12.8 degrees Celsius (55 degrees Fahrenheit). Just in case you were wondering, they improved by 8 percent in hot conditions for both VO2 max and the one hour time-trial.

Control group cyclists had no improvements in V02 max, one-hour time trial performance, lactate threshold and other physiological parameters.

Suddenly, hot rooms, saunas and even non breathable training suits were the latest must haves and even suggested to be a cheaper and more convenient alternative to altitude training.

When it is too hot, it is a shock to our system. This is similar to what happens to our system when we exercise or train in altitude.

When we exercise in altitude, the decrease in oxygen triggers the body to produce more red blood cells. Heat training increases the volume of blood plasma in our bodies and this help send more oxygen to our muscles.

However, it is not totally certain that increasing blood plasma volume may lead to improved athletic performance. What may happen from the resulting dilution of blood is that it may trigger a natural response for the body to produce new red blood cells - just like altitude training.

Training in hot conditions does not only change blood plasma. Other benefits include psychological resilience (or the ability to endure) and altered perception of high temperature. Just like what I intended for by training in the hottest part of the day.

Before you head out and train yourself silly in the heat, make sure you gradually increase your intensity and heat exposure. Drink enough but do not overdrink.

Reference

Lorenzo S, Halliwill JR et al (2010). Heat Acclimation Improves Exercise Performance. J App Physiology. 109(4): 1140-1147. DOI: 10.1152/japplphysiol.00495.2010.

How Quickly Do You Lose Fitness When You Stop Training?

Picture of Singapore Stan Chart marathon by RunSociety from Flickr

Well, many of you've just done your last race of the season. Yes, after the Standard Chartered Singapore Marathon 2016 this morning it's off season time at last.

Now it's time to take some much needed rest, both physically and mentally and not worry about training for a while.

The most common question and worst fear among my patients who run (or race triathlons) is how quickly do they go out of shape if they stop running (or training).

Ever wondered how long before detraining kicks in? Well, just as you don't become a fast runner overnight, you don't lose your fitness that quickly too. Nothing goes up in a straight line, there'll be some peaks and valleys. Likewise you don't lose your fitness overnight too.

Okay, first the good news. Research on detraining or how quickly you go out of shape shows that those who are less well-trained have less to lose. This make sense considering the elite athletes have further to fall.

Elite athletes can lose up to half of their aerobic fitness within the first 12-21 days of not training. They can then lose half of their remaining fitness in the next 12-21 days and so on. The bad news, those who've trained for a few months have a slower decline, but lost all fitness within 4 weeks.

Most studies suggest that an elite athlete's VO2 max levels drop 7 percent if they stop training for 12-21 days. They can lose another 9 percent from days 21-84.

One major reason for the quick fitness decline is the loss of blood volume. In the first 12-21 days that you stop training, you can lose up to 500 milliliters of blood. It's a simple supply and demand situation. When you stop training, you take away the demand.

The body loses the ability to bring oxygen to the muscles and you also have less fluid available for sweating (which cools the body).

The good news is with retraining, you can regain blood volume in a week although it takes a while for your red blood cells to grow again.

Other than blood volume, your mitochondria cell density, lactate threshold and your ability to oxidize fat stores all deteriorate.

Researchers have found it difficult however to measure time to regain your fitness. A common suggestion is that for every week lost, it takes two weeks to regain that previous level. The reason for this all those functional capabilities mentioned above.

When I was still racing, I used to take two weeks off at the end of the season. Yes, two weeks of no swimming, running, cycling and weight training. This allowed me to recuperate both physically, recharge mentally and also to spend time with my family, loved ones and friends. And when its time to train again, I'd be raring to go.

Do bear in mind that not all systems in your body detrain or retrain equally. Do consider your age. Runners in their 20's can resume training as though they never took time off. Older runners will take longer. 

Strength gains (from weight training) are not lost as quickly as aerobic (or cardiovascular fitness) and it usually takes 4 weeks before you start to lose peak muscle strength and maybe that will be another article later on.

So congrats and well done to those of you who ran this morning and make sure you take that well deserved time off.

References

Coyle EF, Hemmert MK et al (1986). Effects Of Detraining On Cardiovascular Responses To Exercise: Role Of Blood Volume. JAP. 60(1): 95-99.

Joyner MJ and Coyle EF (2008). Endurance Exercise Performances: The Physiology Of Champions. J Physiol. 586(1): 35-44. DOI: 10.1113/j.physiol.2007.143834.

Too Much Lactic Acid Causes "Crystals" To Form In Your Muscles?

*What a load of  sh--!

One of my massage therapist asked me today if it's true that with too much exercise, lactic acid can form crystals in your muscles? His friend had been been told by a massage therapist that "crystals" can form in his muscles with too much running and no sports massage to "break the crystals."

This is the 3rd time in two weeks someone asked about this. The first two were my patients.

Apparently they had gone to this particular massage place and were told by the massage therapist there that if "the crystals" in the muscles were not "broken up" it's bad for them and they can't run well. The massage therapist(s) then WhatsApp their patients an article to read.

Now I find this really ludicrous to say the least. I've addressed this issue before. Massage does not flush lactic acid from your muscles.

Any textbook on Exercise Physiology (or you can check online) will explain that you can only accumulate lactic acid in your muscles during intense exercise (e.g. while racing or running intervals). As there is not enough oxygen available, a substance called lactate is formed. Our bodies then try to convert this lactate to energy without using oxygen.

However, this lactate or lactic acid can build up faster in your bloodstream than you can use it. The point where lactic acid starts to build up is called the "lactate threshold." So if you run just below your lactate threshold you won't fill the "burn" in your muscles.

That is what interval training is all about - trying the raise your lactate threshold so you can run at your race pace longer without incurring oxygen debt (or that burning sensation in your muscles).

This "burn" you feel is temporary. Once you slow down and/ or stop exercise, your body can then easily convert the lactic acid to energy. After a short while there isn't any more lactic acid in your muscles. The "burning" sensation in your muscles happen only during intense exercise.

Lactic acid clears very quickly on its own. By the time an athlete has a chance to "use" anything that claims to flush out lactic acid, the lactic acid is probably gone. You don't need help to dissipate it.

Lactic acid definitely does not cause soreness. The soreness you sometimes feel in your muscles a day or two (especially if you've pushed too hard) isn't from the lactic acid accumulation in your muscles. It's most likely delayed onset of muscle soreness or DOMs.

Back to my conversation with my colleague. He then said that his friend said that after a massage session there "to break his crystals" he normally can't run for three days! That's how sore he got. More likely how brutal or how heavy handed the massage therapist was.

When I was still racing, I get sports massage done so I can train/ run long and hard the next day and the day after and after. That's what the sports massage is supposed to do. Helping me to recover better so I can run long and run hard every day if possible. As an athlete, that's what I want to do. If I have to rest three days after a sports massage how do I get my training done?

So be very wary if your massage therapist or even physiotherapist tells you that that you need to "get your crystals broken" or that you need to flush the lactic acid out of your muscles.

*Thanks to my patient for forwarding the article to me.

Don't Start Too Fast In Your Race

Picture by richseow from Flickr

I've written about why why you shouldn't start too fast in your race before. Well. here's the science behind it.

Researchers studied a group of world class orienteers and skiers whose average VO2 max read 80.7ml/kg/min. Now that is truly world class.

The subjects were first made to run hard to tire them out. They were allowed to recover for a few minutes until their lactate levels reach either 3 or 5 mol/L. Thereafter, their running economy was measure while they ran at their threshold pace (or before they start to accumulate lactic acid, usually at 4 mol/L).

The results showed that when they were less recovered (5mmol/L of lactate, their running economy (or how much oxygen and energy required to cover a certain distance) was 5.5 percent worse. This is a huge difference. The authors suggest this would translate to 30 seconds for a 10 minute run, three minutes in an one hour run or 8:25 minutes in a full marathon.

The authors suggest that this should caution anyone starting too fast in a race as too fast a start causes an accumulation of lactate and you'll not be running as efficiently for the latter stages of the race.

Bear in mind that the subjects in the study were tested in laboratory conditions (i.e ideal).

In hot, super humid and sunny Singapore, your running economy definitely worsens after an hour of running. Two hours or more of running? You betcha. If you didn't read how I started too fast (and lost) in my first serious 800m race, read this.

Reference

Hoff J. Storen O et al (2016). Increased Blood Lactate Level Deteriorates Running Economy In World Class Endurance Athletes. J Strength Cond Res. DOI: 10.1519/JSC.0000000000001349.

Don't Set Off Too Fast

Here's a personal experience from one of our patients at a race recently. Standing at the start line, training all gone to plan. Well rested and taper went well. When the horn sounded for the start, the runners at the front burst off and my patient follows. Legs feel fresh, the first few kilometres past quickly, a check of the watch says a PB (personal best) on the cards.

Upon reaching the halfway mark about 8 minutes ahead of schedule, doubt crept in slowly "Have I started too fast". By the finish line, target time was missed by 5mins (let alone a PB) and my patient was left swearing at the unintentional over ambitious start.

How many of you actually heard about the runner (or any runner) who started their race too slowly and finished wishing they'd started off faster? Probably not huh? It doesn't happen very often. But starting too fast is a mistake that even the most experienced runners make. Getting the pace right for a training run is hard, doing it in a race even more so.

Yours truly made the mistake before as well. In my first serious 800m race, I bolted into the lead at the start and led the race til the last 100 metres when I begin to struggle big time. Two of my competitors came around me and I ended up 3rd. I could have placed better or even won had I paced myself better (I proved that point when I won the same event the following two years in a row against the same runners).

That's why you see rabbits (pace makers) in all the big races - Boston, Berlin, London marathon etc. These runners are paid to run at a certain pace for the big guns racing. Those who run track and watch the Golden League Grand Prix meets can testify to that as well. Most of the world records are set this way, with their (pace makers) help. Like most things in running and racing, there is no short cut, you'll have to practice running a certain distance at 3,4, 5 minutes per kilometer to learn how to pace yourself.

You have to be aware of your stride rate, length, breathing pattern, arm swing etc and then observe how they change as you get tired whilst running. As you get stronger, probably all these will get easier and you can step your training up a notch. Using a GPS or heart rate monitor can help, but as you know, all electronic devices are fallible. If you can learn how to pace yourself you won't make be left at the mercy of a flat battery or failing signal. Plus, except for very long races, it is always better to leave the gadgets at home during the races (my personal opinion).

Before your race you would have know from your training what sort of time you can expect to maintain over the distance raced. Find out about the course, know which part of the course has terrain or slopes/ hills that may slow you down. Allow time to get across the start line in races which has large fields and accept that your pacing and finishing time may be affected.
Don't try to make up for lost time in the first few kilometers, try to claw it back a few seconds at a time . And when you can see the finishing or at least hear the race announcer at the end and a race marshal tells you last few hundred metres then you can muster up a decent sprint for the line.

The scientific rationale for this is simply that slower, steadier pace at the earlier stages (of any endurance race) will spare some of your carbohydrate stores since at slower speeds the body is more inclined to burn fat. This means that there will be some carbohydrate available at the later stages of the race so that fatigue and "hitting the wall" can be avoided.

Sometimes wearing a "pace band" around your wrist to clearly show your optimum split times will be most useful. I've seen runners write it on the back of the hands with permanent markers as well.