Ask The Expert: Endurance Nutrition Myths Busted


03.01.19 at 10:04 am

Share this story

How do I improve my training through diet? How can I shift a few pounds and still keep up my power levels? What supplements should I take? These are just a few questions we often hear our fellow cyclists asking one another, but at New Year it seems that we, along with the whole nation, become obsessed with nutrition and exercise. Along with the ‘New Year New Me’ training regimes we embark on cleanses, detoxes and diets galore but often these are lacking in any real scientific basis.

We caught up with Sports Scientist Dr Howard Hurst and asked him some of the most popular questions we want answered, to help you separate fact from fiction.

Endurance Nutrition Myths Busted

Dr Howard Hurst is a Senior Sport Scientist from the University of Central Lancashire and also runs a nutrition and performance consultancy, Proform Sport Science, to help out us mere mortals when he’s got time away from the pros!

Cycling nutrition myths busted, sports scientist Dr Howard Hurst

For someone looking to change their body composition, should their focus be more on cycling nutrition or on training?

For best results, both. Exercise will increase energy expenditure and therefore weight loss, but without fueling correctly that weight loss could be coming from a breakdown in muscle mass rather than fat mass. In addition, sound nutrition will complement training by ensuring you are fueled correctly to sustain the training and prevent weight gain. Conversely, if your goal is to increase muscle mass, nutrition will aid the development of muscle by ensuring you are sufficiently recovered and can train more frequently as well as promoting protein synthesis.

To what extent does the timing of nutrient intake really matter e.g. the so-called ‘Golden Hour’?

The timing of nutrient intake can have a huge effect on performance and recovery. Many people are familiar with the concept of carbo-loading, i.e. increasing carbohydrate intake 1-2 days prior to an event in order to maximise performance, but post-race nutrition is equally important. Muscle glycogen stores take around 24-48 hours to fully replenish. However, research has shown that if you start the refuelling process within the first 20-40 minutes post-race, the so called ‘golden window’, then you can actually cut this down to as little as 12-16 hours. This would help you get back to training more quickly without residual fatigue and would be particularly important if you were competing in a multi-day events.

Over recent years many websites and magazines articles have focused, in my opinion, too much on protein intake during recovery. For endurance athletes, the focus should be more on carbohydrate stores as this is the primary fuel source and replacing fluid losses, as most athletes consume sufficient protein anyway if they have a well-balanced diet.

What are the most common nutritional deficiencies you see in cyclists?

From my personal experience, based in the UK, vitamin D is often deficient as it is synthesised from the sun. Vitamin D is important for bone health, muscle function and also has cardio-protective properties along with providing protection from other diseases. Beyond increasing our exposure to sunlight, other good sources of vitamin D are oily fish such as salmon and trout, eggs and dairy and through supplements.

I also often find that dietary fibre intake is low. This is beneficial for maintaining bowel and gut health, lowering cholesterol and has also been shown to aid fat metabolism. Increasing fibre levels can come from consuming more whole grains, bran, fruit and veg and pulses.

If amateur ‘weekend cyclists’ only took 3 supplements what should they be and why?

None – I always advocate a food first approach. If you are only riding at the weekend then unless you have been diagnosed with a deficiency there is no real need to supplement if you have your nutrition sorted. At most I would recommend taking a carbohydrate drink on training sessions longer than 1.5 -2 hours and above and possibly a recovery drink if you have a way to travel home before you can refuel with foods.

Repeated high-intensity endurance training lowers testosterone levels and raises cortisol levels (which is detrimental to performance & health) – how can nutrition help counteract this?

Longer-term endurance training without proper recovery has been shown to lower testosterone and increase the stress hormone cortisol. Typical symptoms include fatigue, poor performance, difficulty building or maintaining lean muscle mass and a lower libido to list a few. Another factor to consider with endurance training is athletes can often try to reduce body fat too rapidly and too low which can cause hormonal imbalances.

Low testosterone levels don’t happen overnight but take several months, therefore restoring balance similarly will take time. Key to this is adequate recovery through reducing training volume and intensity and ensuring you get at least 8 hours sleep per night. From a nutritional perspective, it is advisable to increase your intake of healthy fats and cholesterol as these are instrumental in hormone production and particularly testosterone. These can come from oily fish, dairy and omega-3 fish oils. Inclusion of zinc and vitamin D supplements may also help re-address low testosterone levels.

What are your views on the increasing popularity of a ketogenic diet for increased cycling performance?

Whilst there have been studies that have shown some positive benefits of ketogenic diets for performance, these improvements were not significantly greater than those participants on a carbohydrate-rich diet. In addition, these studies have been limited to short period of times and have often not used trained athletes as participants. In one of the few well-controlled studies on elite endurance athletes comparing ketogenic, carbohydrate and mixed diets by Burke et al. (2016), those in the ketogenic group actually saw a reduction in performance by 1.6% after 3 weeks, whilst those in the other groups improved by 6.6 % and 5.5 % respectively. To date, there is no scientifically proven evidence to support chronic carbohydrate restriction as a means of aiding athletic performance. I wouldn’t recommend this strategy to any of the athletes I coach. Rather, I promote nutritional periodization instead, whereby different macronutrients are prioritised at different times depending upon training demands. I recently wrote a piece for my website on this topic which you can read here.

Are there differences in the nutritional requirements between male and female athletes?

Surprisingly, the nutritional needs for males and females are quite similar and as already alluded to, will largely be determined by body composition, training type and intensity and the athlete’s goals. However, females should aim to increase intake of iron above males, as significant amounts can be lost each month through menstruation. For females aged 19-50, it is recommended they have around 18mg/day. Similarly, calcium levels for females should be a little higher than males as whilst bone mineral density diminishes for both genders with age, females are more susceptible due to the menopause. Beyond this, the nutritional needs of females is as individual as it is for two different male athletes.

What are the most frustrating nutritional myths and inaccuracies you hear regularly?

Over recent years the increasing demonization of carbohydrates has really irritated me. Carbohydrates do not make you fat, similarly fat and protein do not make you fat. What does make us fat is over-consumption, regardless of the macronutrient. Good nutrition for performance requires all three macros in different quantities at different times (again, refer to my website article for a more detailed discussion on this topic).

I’m also not a huge fan of the use of coconut oil. Whilst there is some ‘evidence’ to claim it increases high-density lipoprotein cholesterols (the good one) and it being more stable under heat for cooking, the current scientific research also shows that whilst HDL cholesterol is increased, it may not necessarily be functional and not reduce the bad cholesterols nearly as much as claimed. My advice is to use it sparingly, as ultimately it is still nearly 90% saturated with long chain fatty acid, which have repeatedly been shown to contribute to cardiac diseases.

Lastly, I often get clients says things like, “yes, but eating healthily can be expensive.” I’m sorry but I just don’t buy into this argument, unless you shop at Waitrose or Marks and Spencer. For the price of McDonalds Big Mac meal (which will leave you hungry an hour later), you can get the ingredients to make a chicken stir fry for three people (I once took a client shopping to prove this as she didn’t believe me!).

Do you consider any commonly used sports/nutrition supplements to be a waste of money?

Creatine may fall into the waste of money category unless you are vegan or vegetarian, as most meat-eaters get enough through their diet anyway. The ceiling for creatine storage is around 160 mmol/kg muscle mass. Most meat-eaters are around 140-150mmol normally. Of all the supplements and ergogenic aids on the market, the only ones that have been repeatedly proven to aid performance are carbohydrate, protein and caffeine products. The effectiveness of other supplements is debatable.

Cycling nutrition myths busted, sports scientist Dr Howard Hurst



Share this story