Running Triathlon

A Simple Guide To Sweat Testing

Because I live in Singapore, the in-person coaching I do is in extreme heat and humidity. As a result, I often see the effects of insufficient hydration. It shows itself in the form of cramps, poor performance, and in extreme cases, collapse.

A large part of my coaching focuses on fueling and ensuring our athletes get enough energy, water, and electrolytes to optimise their training and racing performance.

This article will explain sweat and why sweat testing helps establish a hydration plan that works.

Why Do We Sweat?

Simply put, sweating is your body’s way of cooling itself down. By promoting heat loss through evaporation, sweat helps regulate your body temperature.

Sweat is comprised mainly of water, but it also contains sodium, chloride, potassium, calcium and magnesium.

What Is Sweat Testing, And Why Should You Do It?

We do sweat testing to measure how much sodium you lose in your sweat. There are various methods for measuring sodium loss, but at Coached, we use non-exercise sweat testing in partnership with our friends at Precision Hydration.

Non-exercise sweat testing has the advantage of being less time consuming, and it doesn’t require significant exertion. Also, the collection and analysis process is very controlled and simple. 

The results are highly reliable and reproducible, with a low risk of ‘user error’ in administering the test. For that reason, doctors use non-exercise sweat testing in the diagnosis of Cystic Fibrosis where accuracy is essential.

This method uses chemicals applied to the skin to mimic the effect of certain neurotransmitters that stimulate the sweat glands and allow sweat samples to be collected ‘at rest’. Because it’s effortless, sweat testing is the most enjoyable test we offer in the Coached Lab.

Once we know how much sodium you lose in your sweat, we can customise a hydration strategy that will optimise performance and lower your risk of suffering from cramps. 

You’ll race faster, play better, and recover more quickly after training and racing.

Cut Race Times, Not Corners.

Racing at your potential and enjoying training is easy when you’re following the right programme.

Who Can Benefit From Sweat Testing?

Sweat testing is beneficial for anyone who sweats for long periods or is prone to cramping during exercise.

We’ve tested soldiers, endurance athletes from multiple sports, team sports players, engineers working outdoors, and many others.

The result is always the same; an increase in performance and comfort in hot and humid conditions from those that apply the hydration strategies we provide.

Sweat Testing: The Results

A benefit of the non-exercise testing method that we use is that results are instant.

On completion of your test, we run your sweat through our analyser to determine the sodium lost in your sweat.

Below is my result. 

Sweat test results indictating sodium loss of 1250mg/l

As you can see, I lose 1249 mg/l of sodium in my sweat, which is considered high.

I also have a moderate sweat rate which means I need to pay close attention to my hydration status and fuel carefully during training and racing to maximise my performance and keep cramps away.

You can view my complete result here.

Book Your Sweat Test

If you’re in Singapore and want to measure your sweat, we can measure you in our lab. If you’re not in Singapore, Precision Hydration has many test centres worldwide that offer the same service.

Running Triathlon

Mobility Training For Runners And Triathletes

To kick this article off, let’s start with some definitions. 

Many athletes I speak with often get confused and think flexibility and mobility are the same. They’re not.

Flexibility refers to your connective tissues (muscles, ligaments, tendons) ability to temporality elongate.

Mobility is the ability of your joints to move freely through their full range of motion without pain or compensation.

Range Of Motion
Range of motion (ROM) is the measurement of movement around a specific joint or body part.

While all are important and each impacts the other, mobility is most important for endurance athletes.

Why is Mobility Training For Runners And Triathletes Important?

If you can’t move through the normal ranges of motion required when swimming, cycling and running, you’re not going to swim, ride, or run as fast. 

Mobility is vital for performance and staying healthy, as well as keeping you injury-free. That’s because mobility affects how you swim, ride and run. If you have poor mechanics, that negatively impacts everything you do as an athlete.

Mobility most affects runners and triathletes in these areas …

  • Feet and ankles.
  • Knees.
  • Hips.
  • Shoulders.
  • Spine.

Sufficient mobility in these major joints and strength is the solution to most injury problems and will help you train pain-free and race to the highest level of your competency.

Cut Race Times, Not Corners.

Racing at your potential and enjoying training is easy when you’re following the right programme.

Who Should Do Mobility Training?

In short, all runners and triathletes should do some form of mobility training. 

If you’re injury-prone, work a desk job where you’re seated for hours each day, or are an older athlete, mobility training is even more essential for you.

How Can You Improve Your Mobility?

Mobility doesn’t come fast. You need to work at it consistently.

The good news is that it is easy to incorporate mobility into your routine because it includes many elements of a structured training plan.

Cross Training

Triathletes have this baked into their sport because they swim, bike and run out of necessity, but runners often focus exclusively on running. Lots of low-intensity running will not help to improve your mobility so mix things up. Strength training is an excellent form of cross-training for runners.


Form drills in swim, bike, and run allow you to work on the movement patterns of each sport in an exaggerated way that takes you through a full range of motion.

Dynamic Warm-Ups

Dynamic warm-up exercises are literally mobility training. They help activate your muscles and move you through a larger range of motion than simply swimming, cycling, or running.

Myofascial Release

Foam rollers, stretching, and massage guns help release tight muscles and increase your flexibility and range of motion.

Run On Varied Surfaces

Running on more technical terrain like trails, grass, or sand requires more mobility than running on the road. 

Strength Training

Research shows that strength training — particularly the eccentric, or lengthening, phase of a movement under load — is a great way to improve flexibility and mobility.

I encourage you to look for ways to include mobility training into your weekly schedule. Some methods are easier than others, but any will have an impact. 

Start with the most simple ones for you to implement and gradually progress as you begin to see the benefits of increased mobility.

Running Triathlon

How To Train Effectively In Hot And Humid Conditions

I first came to Singapore in 2000. 

My parents had just moved here with dad’s work, and I was eager to visit. The minute I stepped off the plane, I was hit by a wall of heat and humidity that I had never experienced, and I knew my training here was gonna be a challenge.

The first race I did in Singapore was a 5k running race at Macritchie. Besides having a monkey drop from a tree onto my shoulder and jumping over a monitor lizard – both new experiences – the weather nearly killed me. Like most athletes new to this environment, I swore I would never race another one. 

That thought didn’t last long, and since that time, I have raced in many running, triathlon, cycling, aquathlon and stair climbing races, and have spent countless hours training and racing here and throughout South East Asia in extreme heat and humidity. I have also coached hundreds of athletes to do the same.

Here’s what I’ve learned.

Train Early Or Later In the Day

To achieve the most comfortable training experience, output and recovery, training earlier or later in the day when the sun is lower in the sky is essential. 

The slightly lower temperatures at these times help to keep your heart rate down and output up. You’ll also sweat a little less, making electrolyte replacement and hydration a little easier during your session and afterwards.

This rule applies to the majority of training sessions. However, if you have a race coming up that will have you racing in the heat of the day, it can be helpful to do a few race-specific sessions when you’ll be racing to condition your body for the demands. Just make sure you fuel the session properly – before, during and after – to ensure sufficient and swift recovery. 

Train Indoors

Besides being time effective, training indoors allows you to swap the heat and humidity for an air-conditioned room. Training in cooler conditions, as discussed above, improves the quality of your session and helps you recover faster afterwards, so training indoors can be beneficial when maximum output is the goal of a session or when you’re exhausted.

While it’s helpful to do some training indoors, make sure you continue to train outside to condition yourself for the heat. After all, you will race out, and you want to be ready.

Cut Race Times, Not Corners.

Racing at your potential and enjoying training is easy when you’re following the right programme.

Hydration Matters

I underestimated the importance of hydration for a long time. I didn’t know precisely what and how much to consume, and for years felt tired and sluggish during training.

Dehydration is cumulative, so you must pay attention and stay on top of your hydration at all times to recover and keep energy levels high.

Heat and humidity cause your body to sweat, and with it, you lose electrolytes. Sodium is the primary electrolyte lost in sweat, so salt supplementation is essential in hot and humid conditions.

As well as maintaining fluid balance, sodium plays a vital role in the absorption of nutrients in the gut, preserving cognitive function, nerve impulse transmission, and muscle contraction.

Individual sodium loss varies considerably between athletes. We’ve seen losses as low as 400 mg/l and as high as 2,000 mg/l amongst athletes we’ve tested in our lab. Based on data from Precision Hydration, who provide our sweat testing, the average athlete loses 949 mg/l, which is not insignificant.

If you’re planning to spend any significant time training and racing in the heat, I strongly encourage you to know your numbers.

Firstly, your sweat rate – that is how much sweat you lose per hour. Second, your sodium loss – how much sodium you lose per litre of sweat. Lastly, the duration and intensity of your training session.

Once you know those numbers, you can easily calculate what you need to consume to stay hydrated and maximise your training.

Cap Your HR For Long Training Sessions

When you’re first adjusting to the heat – and in all long sessions moving forward – train with a heart rate monitor below your Zone 2 (steady) ceiling.

Compared to your ‘cool weather pace’, your pace will slow, but the stress remains constant. Your body is simply working harder to cool itself.

As you adapt to the heat and assuming you fuel your training correctly, you’ll see your output start to increase a little at the same heart rate.

Dress For The Conditions

This point is pretty obvious, but you want to dress for the conditions. Avoid wearing layers and heavy clothing. Wear lightweight and breathable clothing; ideally, that wicks moisture away from your body.

We’ve already discussed how critical hydration is when it comes to training in the heat. Choosing your hydration equipment is equally important. Some hydration vests are heavy and can increase body temperature, so minimal and lightweight vests are essential. They’ll keep you hydrated and also minimise the rate at which your body temperature rises.

Round the waist and handheld options are also helpful.

If you can nail the points above, you’ll radically improve the quality of your training in heat and humidity. Your training experience will also improve because it won’t feel as hard as it used to.

Some of the best races during my career were in intense heat and humidity. It wasn’t that I was faster than the others; I just performed to a higher percentage of my ‘cool weather’ ability because I was acclimated to the conditions and knew what to do to get the best out of myself in hot, humid weather.

You can do the same.

Running Triathlon

What Is MAF Training, And Is It Effective?

I first learnt about Phil Maffetone and his work in 2009. 

I stumbled upon his book, The Big Book Of Endurance Training And Racing, as I tried to learn more about fat burning and how you could increase an athlete’s ability to generate energy from fat.

I had moved to Singapore in 2008 to pursue my coaching career, and soon after that opened our first high-performance lab where we started doing a lot of metabolic testing.

Early on, it became clear that most of the athletes we measured were heavily reliant on carbohydrates and not good at burning fat. Many had excess body fat and had trouble in the later stages of races. These issues are a problem, so I searched for the factors that influence fat metabolism, hoping to transform people into metabolically flexible fat burners.

After reading Phil’s book, I knew we were on the right track. 

I grew up in New Zealand and was exposed to the benefits of aerobic training at a very young age. Arthur Lydiard had pioneered the approach to training endurance athletes with a lot of aerobic volume, and most coaches Downunder had adopted his approach since the 1960s. 

It served me well – with a sprinkling of high-intensity training, of course – throughout my pro career, and I was comfortable prescribing aerobic training and having athletes use a heart rate monitor as an objective measure of intensity.

What I was less familiar with at the time was the role nutrition played in fat burning, health and performance. 

What Is MAF Training?

Simply put, MAF training is a philosophy about how to train and a set of tools Phil developed to help athletes perform better.

MAF stands for maximum aerobic function, and the idea with MAF training is to train at, or below, your MAF heart rate ceiling to improve your aerobic function and increase your fat burning ability. 

As Phil says, “there are a lot of fit but unhealthy athletes”, and this is primarily the result of too much intensity in training, a poor diet rich in processed carbohydrates, and high overall stress levels. 

MAF training and the tools Phil designed are a response to those problems. 

The 180 Formula

The 180 formula is a formula for calculating your MAF heart rate. It’s a simple calculation where you deduct your age from 180. You then add or subtract from this number based on several lifestyle factors that Phil has set. The end result is a heart rate ceiling that you do all of your training at or below.

Phil states that this heart rate is suitable for everyone and is the same across sports. I like this formula, and we use it a lot in our programmes, but I disagree that it works for all and across sports. 

Lactate and metabolic testing are far more accurate ways of determining training zones. As we’ve seen many times in our lab, an athlete’s actual MAF heart rate often differs significantly compared with the formula heart rate.

The MAF Test

To track the progress of your aerobic development, Phil created the MAF test. The MAF test is a simple test performed at the MAF heart rate. At Coached, we mainly use it as a running test, but you can also do it on the bike and in other ways.

We aim for the test to last around 40-minutes. That means that you’ll be running somewhere between 4 – 8km for most athletes depending on your fitness level. Once you have determined the distance you wish to run, you run at your MAF heart rate to completion. As you run, your pace slows in response to fatigue. This decrease in pace is normal and expected; however, aerobically fit athletes will slow much less than someone unfit.

Over time, with the proper training and lifestyle habits, you’ll see that your pace at MAF heart rate improves. Below is an example of one of our athletes over five months.

MAF test progression for Coached athlete, Ming

It’s important to note that this athlete wasn’t exclusively following the MAF training protocol. He was on a Coached programme that includes some high-intensity throughout and other specifics. His MAF heart rate was also calculated via lab testing.

As you can see, his pace increased by 2-minutes per kilometre at MAF heart rate in the five months that he tested – a significant improvement.

The MAF test is helpful because it tells you if you’re headed in the wrong direction, either from too much anaerobic exercise, too little aerobic exercise or any imbalance that is having an adverse effect on the aerobic system. It objectively informs you of an obstacle long before you feel bad or get injured and allows you to course correct.

The Two-Week Test

One of the quickest ways to kick start your fat burning is to do the Two Week Carbohydrate Intolerance Test. 

The Two Week Test is a simple but not easy test where you lower the carbohydrates in your diet significantly for two weeks. The reduction in carbs lowers blood sugar, so you produce less insulin. An increase in fat burning is the result.

After the test, you slowly and progressively add carbs back into your diet to see how they impact you.

Here are the results of my fat burning tests that I did at the start and the end of the Two Week Test several years ago.

Orange represents fat being used for energy, while blue represents sugar.

Before Test


After Test


As you can see, you can dramatically change how your body uses its energy in a short time.

I usually do the Two Week Test two to three times per year. We also use it as a framework for our As A Matter Of Fat nutrition challenge that we host inside Coached.

So, Is MAF training effective?

Yes, it can be effective. However, you have to be patient.

If health is your exclusive focus, MAF is a nice option. If performance is your primary goal, there are better training approaches than exclusively training by heart rate at your MAF heart rate.

I’m an enthusiast of the MAF and Two Week Tests and use both personally and with our athletes.

I’m also a proponent of the need to develop your aerobic system and fat burning capabilities. Where the Coached approach differs from MAF training is in the prescription and detail of training.

We still include a lot of aerobic training, especially if you’re recovering from injury or illness. Nevertheless, we carefully use high-intensity training and use hills and other forms of strength training and specifics that help produce a quicker result without compromising health and risking injury.