We used to think of carbohydrates as two different forms, simple and complex. It was generally believed that carbohydrates such as rice and potatoes were digested slowly and simple carbohydrates such as fruits and soft drinks were absorbed rapidly. However, these days scientific research has pointed us to a term that most of you will now probably be familiar with when we think of carbohydrates – Glycemic Index (GI).
GI is basically the ranking of foods based on their immediate effect on blood glucose (blood sugar) levels. Foods are ranked on a scale from 0 to 100 accordingly. Low GI carbohydrates are digested slowly and produce a gradual rise in blood glucose and insulin levels whereas high GI foods (GI index between 60 and 100) break down quickly during digestion and have a fast and high blood sugar response.
The problem with increased insulin levels is that insulin reduces the use of fat for fuel, while also promoting fat storage in the presence of excess calories.
For people looking to get in shape, knowing the GI of carbohydrates is imperative. One hurdle that people face when trying to lose fat or get in shape is going on a diet and feeling hungry all the time. Low GI foods are natural appetite suppressants. Low GI foods help you feel fuller for longer periods of time.
By knowing what the GI is of carbohydrates in your diet, you can also control and manipulate the natural insulin discharge to obtain the maximum effect from your training.
By controlling insulin using the GI of foods you can ensure that fat is burned and that your body is functioning efficiently all day. As part of a calorie-controlled eating plan, this will help promote better muscle anabolism and fat utilisation. Low GI food choices promote fat loss and a leaner, better physique, as they ensure that blood glucose levels remain steady and consequently allow fat to be burnt for fuel.
That doesn’t mean that you should only eat low GI foods, however. High GI carbohydrates also have their place in body toning and building muscle. Carbohydrates that have a higher GI are best used after a workout as they help restore blood glucose and insulin levels after intense exercise. This promotes optimal recovery by speeding nutrient transportation into the muscle cells.
After a workout there is a time window for up to 45 minutes where your muscles are highly sensitive to glucose (carbohydrates). Immediately after a workout you should consume a fast-absorbing protein with a high-carbohydrate glucose drink. I recommend using a scoop of protein powder and mixing it with a scoop of pure dextrose or maltodextrin which can be bought from the supermarket at a relatively cheap price for a kilogram. Dextrose can be found in the beer brewing section of supermarkets, and with a GI of 100 it provides you with an insulin spike at precisely the right time and helps transport all the amino acids from your protein shake straight to the depleted muscles. There have been many studies that show that having a simple shake like this after weight training can more than triple the anabolic drive of weight training.[5][6]
You should follow up this shake with a small protein-carbohydrate meal within 45 minutes after training. By having a small protein-carbohydrate meal 30–45 minutes after your workout it will allow for muscle glycogen recovery and maintain steady blood glucose and insulin levels that aid muscle recovery. Your protein in this meal should come from a lean source such as chicken or fish and a high GI carbohydrate which is not high in fibre such as steamed white rice or baked white potato. Foods that are high in fat and fibre are not desired at this stage as they slow the delivery time of nutrients to muscles.
Recent research[7] has also shown that up to 3 hours after a workout the nutrients consumed within this time frame are directed towards muscle recovery and growth, meaning that these nutrients are not stored as body fat.
For optimum nutrition, have an identical protein and glucose shake just before your workout and avoid training on an empty stomach at all costs. The protein in your shake before training will ensure that your muscles are kept in a positive anabolic state, while the fast-absorbing carbohydrates provided via the glucose in your drink will help fuel your workout and transport the protein into the bloodstream rapidly.
Poor food choices after around workout create rising and falling insulin and blood sugar levels. This disrupts your anabolic drive and stops your body-shaping efforts dead in their tracks.
GI Factor and Muscle Building
