Protein is one of the most talked about nutrients. Many products nowadays have added protein. Although this is mostly marketing driven there is also evidence that more protein is often considered better, at least up to a point. However, occasionally we also read reports that a higher protein intake may be detrimental for health. And recently a study received disproportional attention in the media after linking a high protein intake to cardiovascular disease risk. Here we will take a closer and more critical look at the study. Protein intake: good for muscle, bad for the heart? Protein is re ..read more

In a series of previous blogs on mysportscience, the role of blood glucose was discussed and we highlighted what insights Continuous Glucose Monitoring (CGM) can provide athletes now and possibly in the future. In this blog, Dr Nicola Guess highlights the multifactorial nature of glucose metabolism, challenging the notion of straightforward causal links between food intake and glycemic responses. In previous blogs Dr Mike Riddell and I discussed opportunities and also some limitations of CGM. CGM in sport Is CGM a fuel gauge? Are CGMs accurate? How can CGM be used? There are many ways in wh ..read more

Current sports nutrition guidelines recommend distributing protein intake in multiple equal meals throughout the day (1). This concept of protein distribution is primarily based on studies suggesting that only a limited amount of protein ingested in a single meal can effectively be used for muscle protein synthesis (the process that allows muscle to recover and adapt to training). It was believed that there is a linear increase in muscle protein synthesis up to doses of approximately 20 g protein, with a relatively small 10-20% further benefit when the dose is further increased to 40 g (2,3 ..read more

Glycogen is essential for high intensity exercise performance. A review concluded that elevated glycogen concentration can improve performance by 2-3% and endurance capacity by 15-25%. Muscle glycogen concentrations can be increased by eating a diet that is rich in carbohydrate. However, studies in the 70s suggested that extreme glycogen loading protocols resulted in very high muscle glycogen concentrations. These protocols employed combinations of high carbohydrate days, low carbohydrate days and extreme exercise to achieve this (see a previous blog). Athletes successfully used these carb loa ..read more

In previous blogs we have discussed the role of protein intake for muscle protein synthesis. However, muscle contains many different functional proteins. While most research has focussed on contractile proteins, muscle also contains many connective proteins that play a very important role in transferring forces along the muscle. As much as 80% of the contractile force is transferred through the connective protein network before reaching the tendon to facilitate joint movement. These connective proteins are found both inside the muscle cells and well as on the outside of these cells. Components ..read more

Fructose can constitute a substantial energy source in the human diet. It is a dispensable (non-essential) nutrient, and no adverse effects of a fructose-deprived diet have been reported. However, specific fructose-metabolising enzymes are expressed in most mammals, including humans, indicating that this source of energy most likely conferred some metabolic advantage at some point during evolution. In athletes, fructose is often used in addition to glucose or maltodextrins as a way to deliver more carbohydrate and improve endurance performance. This blog describes the possible role of fructose ..read more

In 2003, we discovered that certain combinations of carbohydrate could be absorbed faster in a sports setting. Before this discovery it was believed that the maximal amount of carbohydrate that could be delivered to the muscle was around 60 grams per hour (or 240kcal per hour). With energy expenditures over 1000 kcal/h in some endurance sports it was speculated that delivering more carbohydrate would help performance. This blog outlines the science behind carbohydrate ratios for sports performance. The science behind carbohydrate ratios No matter what protocols were used and what type of carbo ..read more

The question of whether mild dehydration (~2-3% body mass loss) really affects athletic performance is crucial. While several studies indicate that dehydration impairs various aspects of performance, the methodologies employed may introduce confounding variables (e.g. lack of blinding). In addition, research predominantly involving males raises questions around hydration recommendations for females, with evidence showing possible differences in sweating rates and sodium concentrations. This blogs outlines important considerations for measuring the effect of dehydration on performance, with con ..read more

Iron deficiency is a prevalent issue among athletes, which can significantly affect training consistency and performance if left untreated. Where possible this should be fixed with good nutrition containing high iron foods that are easily absorbed and possibly the use of iron supplements. See these blogs to learn more (blog 1 and blog 2). In severe cases and in cases where the nutrition approach is ineffective the use of parenteral iron therapy (iron infusions or injections) may be considered and this is what we will explore in this blog. Iron deficiency Multiple mechanisms are related to iron ..read more

It's 4:30 AM as the laces of the thick soled fire boots are tightened. The only light comes from a headlamp and the inside of the tent is covered in dew. As the tent is unzipped, the stars above the Los Padres National Forest light the clear sky: it is freaking cold. A 2-member researcher team flew in by helicopter the day before to link up with a Hotshot crew they are studying. It’s not every day urine sample collection is prefaced with a helicopter ride into the wilderness. Wildland firefighters For the last 25+ years, Brent Ruby from the University of Montana has been chasing down samples t ..read more