Tag Archives: general knowledge

What the heck does Isotonic mean anyway??


Dear Roulers,

On my recent Easter holiday I was laid low by a very nasty stomach bug. I’ll spare you the details, but it pretty much ruined my first trip to Kuala Lumpur. I didn’t eat any of the very nice chocolate my wife had bought until I came to Australia. I digress, back to the point of this blog, in the middle of a very average night I’m really dehydrated, I reach into the hotel minibar and find this weird drink called 100Plus.

I’m desperate, so I sip the drink slowly over the course of a few hours. It tastes bland and most importantly stays in my stomach. I look at the can and there’s some blurb about the drink being Isotonic. At the time I wondered what that meant and thought nothing of it.

About month later I’ve run out of Staminade. I’ve been buying the stuff for years as a means of having non-vile tasting liquid to drink whilst cycling.


At this point I’m putting in a shameless plug for Staminade being made here in Australia…how rare these days…and raise a 2 finger salute to another couple of US drinks ending ‘ade’.  I buy another container at local supermarket and I notice that word again ‘isotonic’….hmmm some little gears whirl around in my head….ah ha I’ve made a connection back to that awful night in KL. So what the heck is isotonic? And why is it important.

Enter the science of the sports drink as provided by Google….
The basic theory goes like this. Being hot and dehydrated is bad. I’ll dispense with the explanation. It should be self-explanatory.  Plain water will keep you hydrated not fuel your muscles. Research has shown that body will perform better if your drink contains some carbohydrate. But it mustn’t be too much, fruit juices and sugary fizzy drinks can dehydrate as the body uses available water to dilute them and enable the carbs to be absorbed.

So much to my surprise sports drink can belong to one of three categories: Isotonic, Hypotonic and Hypertonic. Essentially these words describe how rapidly the fluid and carbs are absorbed through the stomach.

Type of Drink Description
Isotonic Drink These drinks are said to be in balance with the body’s fluid levels and empty easily from the stomach into the bloodstream. They contain somewhere in between 5 to 8 grams of carbs per 100ml. Some have sodium to assist absorption. They can be consumed at anytime while cycling.
Hypotonic Drink These drinks are absorbed by the stomach faster than Isotonic ones, but this is achieved by having low levels of carbs. They are very useful for hot conditions, where you are working up a sweat. However as a long distance cyclist you must eat something as well to keep your energy levels up.
Hypertonic Drink These drinks are the slowest to be absorbed by the stomach. They have upwards of 10 grams of carbs per 100ml. They provide plenty of energy, but can hinder hydration, as discussed earlier. They are best consumed after cycling, possibly when you are too tied to eat food.

A word of caution…drinking strong hypertonic fluids can reverse the normal process of osmosis and cause diarrhoea. Think Greg LeMond, Tour de France circa 1986. Which brings me full circle to KL and the 100plus drink in the minibar. Ta da 🙂

Until next time


Choosing Pedals

The Breakaway

Try riding a bike without pedals 🙂 Its pretty useless and begins to look a lot like riding the original 1817 bike the “Draisine”. Pedals are an essential part of your bike riding experience so you should know something about them.

The Leadout

There are 2 main types, Flats and Clipless:


Most history books credit the invention of pedals, mounted on opposing cranks to the Parisian Pierre Michaux in 1863. He attached cranks to the front wheel pedals on a draisienne. This invention was known as a velocipede.


The clipless pedal was invented by Charles Hanson in 1895. Not much happened with it until 1971 when Cino Cinelli developed the M71, in 1971. Referred to as “death cleats”, this pedal was designed mainly for track racing as cyclist had to reach down to them to unclip them.

Clipless refers to the toe clip (cage) having been replaced by a locking mechanism. “Clipping in” changes the way a cyclist is able to pedal, with push down and pull up, being available to transfer power into the bike’s gearing and rear wheel.

The Peloton

Even with these two basic types there are plenty of options.

Flats Without toe clips Wellgo Flat These are the most basic option. Flat pedals provide a platform for a cyclist’s leg and foot to push down on. They can be used with most kinds of footwear (Although I can honestly say, that I’ve never tried them with high heels :-). These are recommended, if you need to hop on and off trains, walk or ride in work clothes. Generally, they are the cheapest option.
With toe clipsQuill Flat French cyclist Eugène Christophe is viewed as the inventor of the toe-clip. In 1925, he sold his invention to Poutrait-Morin (known now as Zéfal). The next step from flats are toe clips. These consist of flat pedals with a basket-and-strap “cage” attached to which hold the foot in place.
Road Look and Look-a-likes Look Keo The first modern clipless pedal was designed by the French company Look. Look applied downhill snow skiing binding or cleat technology to pedals. Bernard Hinault’s victory in Tour de France in 1985 then helped secure the acceptance of quick-release clipless pedal systems by cyclists. Look cleats and their many Look-alikes (tee hee…couldn’t resist) are large and protrude from the sole of the shoe, unlike SPD. This provides a larger platform for transferring power through to the pedals. The protruding cleat makes these shoes impractical for walking, as doing so can damage the cleat. These are recommended for competitive road cyclists looking to improve their performance.
SPD Shimano SPD SPD stands for Shimano Pedaling Dynamics pedal system. Released in 1990, these clipless pedals are arguably the most versatile and best suited to urban commuting or mountain biking. SPD cleats are small and could be fitted in a recess in the sole, making it possible to walk reasonably comfortably. SPD Pedals are the next step up for the average cyclists. They can be single or double sided. This enables a cyclist to clip in with cleats or use the flat side with normal shoes. They allow for a large range of adjustment to make ‘clipping in and out’ much easier. SPDs are recommended for cyclists ‘clipping in’ for the first time, commuters and mountain bikers. Cyclo-cross rider tend to prefer them as well.