WTF are BIOMARKERS?

What you need to know

BY NUTRITIONIST RENEE MCGREGOR

Are you ready? Long hours of training can take their toll and damage your gains.

So you’ve nailed training and nutrition and your next fitness challenge is just around the corner. But are you ready for it? Sometimes our competitive edge can compromise our rational mind into thinking we’ve got all our ducks neatly lined up.

Psychologist Sander van der Linder said, “Competitiveness is a biological trait that co-evolved with the basic need for human survival,” and while this can be used in any context, it explains why so many of us are always in search of the next challenge, and the next achievement. We record our training sessions and use the numbers as validation that we are progressing.

But while being driven is a positive trait – helping us to roll out of bed and lace up our trainers – it can be a little like walking a tightrope. Stay balanced and you will reap the rewards, but push too far and that same trait can become dysfunctional, leading to increased risk of injury and potentially longer-term health consequences.

So how can we truly know that all of the so-called good work we put into our fitness regimens and dietary choices is really working? And can we really use how we feel as an indicator of optimal health and performance?

Nothing to chance

How you feel, combined with how you perform, is of course a fairly reliable indicator, but anyone who takes their training seriously can also benefit from monitoring. If you really want to get the most out of someone’s performance, you have to understand how their body is responding to their training load – only then can you provide them with appropriate nutritional interventions. Strength-based testing is one method, as is monitoring sleep. I also encourage athletes to rate their energy levels (although this is subjective) and their motivation to train. Doing so can tell us a lot about their physical and psychological status.

However, I also go one step further. My biochemistry and clinical background in nutrition has always meant that I have a real interest in what’s going on within the body. Monitoring biomarkers or, more simply, blood values of key markers such as iron, vitamin D and hormones, can tell us about inflammation, as well as immune, bone and hormonal health, which tells us about an athlete’s readiness to train or compete.

Looking at specific blood biomarkers can help us get a grip on what is really going on within the body.

Inside edge You don’t have to be an elite athlete to benefit from testing biomarkers – anyone who trains hard and is looking for results will benefit.

IRON

I generally look at haemoglobin, ferritin (iron stores) and transferrin saturation, which helps to identify absorption of iron from the gut. It’s important to identify low levels, because a deficiency will have a negative impact on appetite, energy levels and overall performance. It’s also important to look at all three values for a full picture: values of haemoglobin should be 14 or above, ferritin 40 or above and transferrin saturation above 20 percent in anyone who’s very active.

VITAMIN D

The winter’s drizzly weather isn’t just detrimental to your tan; studies show the lack of sunlight in winter means vitamin D deficiency is common. The consequences are low immunity, low mood and low energy levels. For anyone who exercises on a regular basis, that means the very real problem of reduced recovery between sessions and increased muscle soreness. Acceptable levels of vitamin D for the athletic population should ideally be above 90 nanomoles per litre (nmol/L).

THYROID

The thyroid gland is integral to our health and performance on so many levels. These levels are of particular interest to me when I’m monitoring either endurance athletes or those doing very heavy lifting. I will look at the following hormones: thyroid stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, testosterone and Free T3. When we over-reach, overtrain and/or under-fuel, we create more stress to the body. This stress has a negative impact on the pituitary gland, which can then dial down our thyroid function.

Monitoring TSH can help identify those at risk, while looking at T3 can indicate low energy availability. In other words, if T3 is low, we can conclude there’s not sufficient energy being taken on board to fuel training and maintain basic biological processes. This, in turn, can lead to reduction in production of the sex hormones. Chronically low testosterone levels, meanwhile, will have implications on bone, cardiovascular and immune health, as well as overall mood. In men, testosterone levels under 10 will mean they are less likely to respond to their training stimulus – whether that’s strength- or endurance-focused. Timing and composition of fuelling around training is critical in keeping these biomarkers in check.

Check, mate A simple blood test can give you some incredible insight into your health and training.

C-REACTIVE PROTEIN (CRP) CEATINE KINASE (CK)

Monitoring levels of c-reactive protein and the enzyme creatine kinase can give us direct information about the level of inflammation in the body. While exercise will inevitably result in raised levels, these biomarkers can be a good indicator of recovery rates after high-volume training blocks or competition, and also hints at the risk of overtraining. This is definitely something I look for when individuals I work with are looking to go back to training after competition, especially those who do endurance and ultra-distance events such as Ironman. Returning to training with raised levels will increase risk of injury, as well as overall stress on the body.

9AM CORTISOL

While levels will be highest in the morning, a consistently high level of cortisol indicates the body is under stress, and that could be the result of lack of recovery, poor sleep, high anxiety levels or poor fuelling. Regardless of the cause, chronically high levels will have negative consequences to immune and metabolic health, including a dysfunction in fat and carbohydrate metabolism, which can result in the body preserving energy and holding onto visceral fat. This explains why some people train with intensity but stay the same shape: the harder they work, the more stress they create and the more fat their body clings on to.

This list gives you an idea of the key markers to monitor in order to progress your training. If you don’t have any medical symptoms, monitoring these biomarkers may not be available on Medicare; in these cases you could try a service like i-screen (i-screen.com.au), which provides a variety of checks, and consider recurring tests to help you periodise your training. ■