How can blood tests help nutrition and performance plans?
Blood tests are a good way of confirming optimal body function and also screening for potential nutrient deficiencies. A sports dietitian will use results to help tailor nutrition and supplementation plans. The following are a good start:

  • Complete or Full Blood Count (FBC/CBC): detailed info  about your red and white blood cells and can be used to detect conditions such as anaemia caused by iron and/or vitamin-B12 deficiency. 
  • Levels: Vitamin B12, Iron and Ferritin (a marker of the body’s iron stores), Zinc and Vitamin D.
  • Lipid profile: triglycerides and cholesterol including HDL and LDL. 
  • HbA1C: measuring glycated haemoglobin (HbA1c) gives an overall picture of what average blood sugar levels have been over a period of weeks/months.

How can I ‘train my gut’ for better outcomes in training and races?
Endurance athletes – indeed most athletes – are pretty familiar with stomach discomfort or distress during training or racing. During longer activity, we have to be able to take on fluid and fuel to sustain effort, but just like the rest of the muscles in our body, the gut needs practice in order to do this. Luckily, like the gut muscles are pretty adaptable and trainable to cope with the stress it's put under during exercise. To get your gut competition ready:

  • Start in training: get it used to having more volume under lower stress conditions.
  • Start by eating/drinking before easier sessions: but work towards replicating fuelling plans before and during your key workouts. This has a dual benefit of getting your gut familiar with foods and fluids and being able to absorb on the go ready for race day; as well as maximising the output of that particular session. 
  • Focus on high carb foods and/or carb based fluids. 

How can I understand more about my hydration/nutrition requirements on long rides/runs?
There are so many individual considerations when it comes to nailing your hydration and nutrition plans. But some key considerations and strategies include:

  • Weigh yourself pre and post training to get an idea of fluid losses: You definitely don’t want to try and match intake with losses, but having an idea of fluid lost through sweat can help guide how much you need to replace during recovery (150% of losses in the couple hours), as well as give you some indication of how well you manage to stay hydrated.
  • For longer slower training, and even racing: drinking to thirst is generally fine. As long as you have access to palatable and cool fluids – i.e bike bidons, stops on runs – then your thirst signal should be enough. For shorter, more intense races, or technical training or in very dry, very humid or at altitude – then staying hydrated needs more of a plan or a schedule.
  • You can invest in sweat testing to understand your individual needs: but don’t forget the basics of keeping an eye on urine colour and frequency – this actually gives a pretty reliable indication. You are looking for straw coloured pee – if it’s uncoloured and high volume, then back off the fluids for a while. On the flip side – very dark urine or if you can’t remember when you last peed – then find water fast. 
  • When it comes to fuelling: the best approach depends on other goals such as body comp, race season, recovery status and goals for that session. In general though – for longer runs and rides – start fuelled, then aim to take on at least 50g carbs/hour to maximise output and speed up recovery post session. Long rides and runs provide the perfect low stress way to practice race fuelling and get used to eating and drinking. If you plan on racing longer Ironman events, then getting up to 90g carbs per hour should be trialled in training.
  • Experiment: treat yourself like a science show – trial, record, adjust and plan. Getting things right is a continual process of self discovery and evaluation. What’s right for someone else may not work for you. Nutrition is as much art as it is science. 
  • Remember to factor the fuel taken on these sessions into the day and week as a whole. Portable, convenient sports foods and drinks, which might be ideal for these sessions and races – are unlikely to add much nutritionally long term. This means focusing on real, whole foods (plenty of fruit, veg, whole grains, quality proteins) the rest of the day and adding in supps if necessary to address any gaps between output and input. 
  • Get help: Sports dietitians can help you nail down plans for training and racing that take in all your individual goals and circumstances.

What’s the best approach towards simplifying fuelling on race day?
Whatever the race and whatever your level of experience, the top tips for race day fuelling remain the same. Sometimes we can overcomplicate nutrition plans and forget to listen to our own body cues. Start (or revisit) the basics first:

  • Eat: even if you're nervous, and even if it’s a short race. You still need energy – even if that is for mental focus. If you can’t eat – then go for liquid calories, like a smoothie or high carb drink. 
  • Check your pee: urine colour and frequency will give you a good indication of hydration status.
  • Eat early: then eat often if it’s a longer race – anything over 1.5 hrs and you will want calories on a regular basis. This can range from 30g carbs per hour right up to as much as 90g/hr. 
  • Keep it simple: it’s best to practice as close to what you plan on having during a race as possible. But if you haven’t – then go for foods you’d generally eat. 
  • Carbs are king: protein and fat will slow gut absorption and won’t provide the faster energy sources required for racing. If it’s an all-day affair, then fat and protein can be valuable additions in smaller quantities, mainly for taste and maintaining a desire to eat.