Carb loading is a sacrosanct part of the training cycle. In the days leading up to a race, the committed distance runner is compelled to eat an industrial amount of carbohydrate-rich food. That’s why you’ll see things like ‘Pasta Parties’ the night before marathons. Best wireless headphones influential studies found that intensive exercise followed by a few days of carb loading could double muscle glycogen, which is how carbohydrate – the body’s preferred source of fuel – is stored in the body.
However, while carb loading is often taken as a given, the evidence isn’t as robust as you might assume. Some studies show huge increases in glycogen while others show minimal uplift. What we need, then, is some clarity – and that’s where a new study comes in.
What did the study involve?
The meta-analysis of 30 studies looked at decades of research. Its aim was to find out the efficacy of carb loading in boosting glycogen stores and what factors affect it. To qualify, studies had to satisfy three criteria:
What everyone's reading
- Here are four interesting things that the meta-analysis revealed
- Be followed by three to five days of carb loading
- Include direct measurements of glycogen post carb loading.
Best Garmin deals...
1. Think percentages not grams
Here are four interesting things that the meta-analysis revealed percentage Nutrition tips for runners with chronic illnesses absolute grams of carbohydrate isn’t so important. Essentially, once people’s intake was ‘sufficient’, the gains levelled off. So, aim for a diet that’s 70-90% carbohydrate in the two to three days leading up to a race.
2. Beware muscle damage
A number of running studies showed reduced or absent uplifts in glycogen stores following a period of carb loading. Why? The authors suggest that muscle damage from eccentric contractions – particularly apparent in hard downhill running – may impair glycogen re-synthesis.
3. Cyclists get bigger boosts
The two-wheeled brigade experienced an average glycogen increase of 270mmol/kg (the fancy way of expressing glycogen content in muscles) compared with runners’ 157mmol/kg. That’s a big win for cyclists.
4. Start low
The more depleted people’s glycogen stores before carb loading, the bigger the boost afterward. In reality, this might mean a running session combined with a slightly lower carbohydrate intake for a few days before carb loading. However, this needs to be done in a sensible, informed way – under-fuelling will hamper performance, not improve it.
