"Now the trouble starts, got advice from someone to use the Leppin Squeezies for energy so hoover down my second one before Little River with some water. Set myself a good pace upto Hilltop and felt good til 1K from the top, then my guts started turning over and I lost the lot all over the road on the next climb.
The result was I could feel my legs dying so I had to drop the pace with a real sore gut, and watch a couple of small bunches go by without the energy to hold em."
(Excerpt from a cyclist's race report - Le Race 2010).
Energy gels, of which Leppin is just one, are heavily promoted to endurance athletes. What we seldom hear about are the downsides of consuming carbohydrate gels when exercising close to our limits of intensity and endurance.
Far from being steady state, cycle racing is more akin to a constant succession and micro sprints, full-on sprints and the occasional rest while going downhill or heading into a corner. This kind of exercise steadily builds the body lactate levels to near intolerable and pushes the heart rate to maximum.
During intense cycling, the body diverts blood flow to the digestive organs the the leg muscles, so any digestion that takes place is mostly passive. Because digestion is so poor during intense exercise, anything ingested must be easy to absorb. It must be very mild on the stomach because high blood lactate makes the cyclist feel sick and liable to throw up if anything that does not agree.
Sport gels are more likely than most carbohydrate supplements to cause gastrointestinal upset because when the carbohydrate concentration in a sports drink is greater than 6-8%, vomiting and nausea are more likely. At 6%, 200ml of a typical sports drink provides only 12 grams of carbohydrate. But energy gels provide 20-30 grams of carbohydrate, plus a whole lot of other ingredients that can include caffeine, sodium and potassium. So, it makes sense that consuming too little water while using these energy gels may partially explain why some athletes get a seriously upset gut after taking these.
It would seem the main fault of the cyclist quoted above was to consume a Leppin with not enough water just before hammering up a hill that was sure to send lactate levels into the stratosphere!
Another issue I have with gels and sports drinks in general, is tooth decay and gum disease. A sure way to rot your teeth is to dry your mouth out with intense exercise and then bathe your teeth and gums with sticky sugar at regular intervals over the next few hours. The best thing to drink during training is plain water and to have a solid refreshment now and then, making sure you swill some plain water about the teeth and gums immediately afterwards. During racing, using a sugary drink is permissible and probably necessary; but make sure you have fully tested the solution in training - such as during an intense time trial or interval work.
I personally think sports gels are an expensive waste of money and are of no nutritional value to the health conscious athlete. I do not think there is any credible evidence that gels are superior to anything else, including plain sugar in water which is probably better.
As an aside, the use of gels is heavily promoted in sports publications and often the sponsor of events. I believe this unduly influences the nutrition advice that is given to athletes in that it is skewed in favour of these products. Little space is given in "mainstream" to explaining in a balanced way the cases for and against these and other sports supplements. For example; Several years ago, I was asked to write a training guide for a mountain bike competition. In it, I advised that "water was best" for training. When it was submitted to the Event Director, my involvement suddenly came to an end with no explanation given. The event was sponsored by Leppin at the time.