Can we approach nutrition for Paralympians in a more functional way?

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Paralympic and disabled sport is fast becoming one of the most hotly contested areas in sport. From its early beginnings in the mid-20th century at Stoke Mandeville, participation in Paralympic sport has grown explosively worldwide, regardless of the reported 10 per cent drop off in participant numbers since the London 2012 games, as reported in the Independent newspaper (1).

Yet, despite this explosion of interest, the same cannot be said for our approach in terms of sports nutrition for these unique athletes.

What’s in a name?

Even defining a Paralympic and disability athlete (PDA) can be a challenge; and the principle component within this sports performance sector, which the International Paralympic Association (IPA) aims for, is to prevent the threat of ‘one-sided’ competition. In essence, to avoid a scenario where the least impaired athlete always wins.

Following this principle, the IPA allows 10 eligible impairments for PDAs to qualify for classification (2). These include:

  • - Muscle power
  • - Range of movement
  • - Limb deficiency
  • - Leg length difference
  • - Short stature
  • - Hypertonia (an abnormal increase in muscle tension)
  • - Ataxia (lack of coordination of muscle movements)
  • - Athetosis (involuntary movements and difficulty maintaining a symmetrical posture)
  • - Visual
  • - Intellectual

The minimum disability criteria are very much defined on the basis of scientific research, which assesses the impact of impairments on sporting activities and is sport-specific. This is simply because the activities performed are often very different. As a consequence, it is very possible that a PDA may meet the criteria in one sport but then not meet the criteria in another.

Fear stops support of PDAs

It sounds ridiculous given that one in five people in the UK (nearly 13 million) report having at least one impairment (3), but I very commonly see practitioners from all health and performance disciplines refusing to work with athletes with impairments on the basis that it will be fraught with difficulty. There are a number of barriers created by a lack of exposure in their previous education or training, and from experience, very little opportunity for practitioners to work with these athletes unless they actively seek them out.

Unique physiology, body composition and medication warrants a functional approach 

Metabolically speaking, PDAs range from having very little difference in biochemical variance from able-bodied athletes to having very severe impairments that require some pharmacological intervention to manage the symptoms.

Differences in body stature and limb deficiency makes assessing body composition a unique challenge. For practitioners, density assessment methods (e.g. BodPOD) and Dual X-ray Absorptiometry (DEXA) are considered the ‘go-to’ option when available (4). Conventional skinfold equations were derived from able-bodied individuals and should be avoided. In the absence of a densitometry assessment, taking limb girths and tracking bodyweight may be the only way to provide reliable data on body composition.

Limb deficiency produces a loss of lean body mass and alters total energy expenditure at rest. According to indirect calorimetry studies, this makes predictive equations very limited for practitioner use (5). However, as the PDA increases their activity, this can dramatically alter due to the additional energy expended using prostheses, with some authors citing up to 60 per cent more energy and a greater proportion of VO2max versus ABAs in ambulatory studies. This issue further compounds as the individual starts to sprint on a running-specific prosthesis or has to make sudden changes of direction. It is not uncommon for PDAs to suffer enormous variations in daily energy levels because of this.

Under the same thought process, PDAs with spinal cord injuries (SCIs) exhibit a significant loss of fat-free mass (FFM) below the site injury, in the region of 18-46 per cent loss of cross-sectional area compared to ABAs (6). The effect of this appears to be an increase in the infiltration of lipids in soft tissues, particularly in the sub-lesional limbs and viscerally compared to able-bodied controls (7, 8).

Practitioners should anticipate the potential range of medications that PDAs can present with and how these could impact nutritional status. Common medications include corticosteroids, non-steroidal anti-inflammatory drugs, antidepressants, anti-spasmodics, anti-convulsives, prokinetics, proton pump inhibitors, laxatives and enterally fed medical nutrition products. These are all to be expected and this list is not exhaustive. The functional practitioner should be fully aware of which nutrients may be at risk and be ready to supplement or fortify the diet or liaise with the wider medical or support team if side effects, such as an increase in appetite or change in mood, occur.

As you can imagine, this combination of a loss of FFM, increase in lipid deposition and potentially medication that increases appetite, has downstream effects on glucose intolerance, insulin resistance, hyperlipidaemia, cardiovascular disease and obesity risk for these individuals. Access to practitioners who will look to embrace a number of avenues to support their health and performance is to be championed.

From principles to plate

It is now widely accepted among those working in sports nutrition that nutritional guidelines are not transferable between athletes of different disciplines. Broad nutrition requirements of a particular sport are of little value and practitioners must instead define what an individual needs based on the intensity, duration, volume of training or competition, presenting clinical issues, genomic data and, of course, food preferences. This couldn’t be more the case for PDAs. Personalisation of nutrition is becoming the basic need for athletes and functionally-orientated sports performance nutrition may well be the final frontier for PDAs to get the support that they need. 

References:

  1. Coles, B (2018). Exclusive: Disabled sport in crisis as numbers of participants drop by ten per cent since London 2012. The Telegraph. Available at: https://www.telegraph.co.uk/paralympic-sport/2018/08/15/disabled-sport-crisis-numbers-participants-drop-ten-per-cent/ [Accessed 25 January 2018].
  2. IPC. Classification Introduction. Available at: https://www.paralympic.org/classification [Accessed 25 January 2018].
  3. Sport England (2016). Mapping Disability: the facts. Available at: https://www.sportengland.org/media/3988/mapping-disability-the-facts.pdf [Accessed 25 January 2018].
  4. Keil M et al (2016). Measurement precision of body composition variables in elite wheelchair athletes, using dual-energy X-ray absorptiometry. Eur J Sport Sci. 16(1):65-71.
  5. Howell A et al (2015). Use of predictive energy expenditure equations in individuals with lower limb loss at seated rest. J Acad Nutr Diet. 115(9):1479-1485.
  6. Castro MJ et al (1999). Influence of complete spinal cord injury on skeletal muscle cross-sectional area within the first 6 months of injury. Eur J Appl Physiol Occup Physiol. 80(4):373-8.
  7. Spungen AM et al (1985). Soft tissue body composition differences in monozygotic twins discordant for spinal cord injury. J Appl Physiol. 88(4):1310-1315.
  8. Edwards LA et al (2008). Visceral adipose tissue and the ratio of visceral to subcutaneous adipose tissue are greater in adults with than in those without spinal cord injury, despite matching waist circumferences. Am J Clin Nutr. 87(3):600-607. 

Rick Miller is a clinical and sports dietitian based in central London. He is a holistic practitioner and approaches sports performance nutrition from a functional perspective, specialising in gastroenterology and IBS management in athletes of all disciplines. His services, personal blog and contact details can all be found on his website: www.rick-miller.co.uk