Morphology-Related Health Risks in Elite Triathlon Liz Broad, PhD, Manager of Clinical Services, Sports Nutrition, Australian Institute of Sport
OVERVIEW • What do we mean byy morphology? p gy • What is the morphology of an elite triathlete? • Has this changed g over time,, and is it different between Olympic distance and Ironman? • What is optimal for performance? • What risks might be associated with achieving an optimal morphology? • What do we have to look out for?
Morphology • Physical y characteristics of a human being g • Includes: – – – –
Body fatness Limb lengths Muscle mass B Bone breadths b dth
• Much of this is genetically pre-determined
What do we commonly measure in practice? • Surface anthropometry: – Skinfold thicknesses, sum of 7 or 8 skinfolds (ISAK methodology). ) Track changes over time. – Stretch stature – Body mass – Girths (e.g. arm flexed, waist, gluteal, mid thigh, calf) – Limb lengths, bone bredths
• DXA scan: – % body fat – lean body mass (total and segmental) – must use standardised procedures for body composition
Has morphology changed in the past 12 years?
Differences in body fat levels across the whole field is less now at elite level than in 2000.
Is morphology different in Olympic Distance v’s Long Course?
Many people believe that Ironman athletes have a greater muscle mass than Olympic distance (i.e. heavier for the same height, equally lean)
Has there been much change over time? ITU world champs winner, 20002010
Ironman world champs winner, 2000-2010
Height (cm)
Weight (kg)
BMI (kg/m2)
Height (cm)
Weight (kg)
BMI (kg/m2)
165
60.5
22.2
165
50.0*
18.4
152
58.2
25.2
180
57 7 57.7
17 8 17.8
160
49.1*
19.2
160
51.7
20.2
180
60.0
18.5
167
57.3
20.5
170
60.0*
20.7
167
55.0
19.7
170
57.3*
19.8
160
51.8
20.2
NB Reported figures, ? Accuracy (especially highlighted ones). * = multiple p winner
Pre 2000 (pre draft-legal racing in elite senior i OD) • 1991 – closer to swimmers than to runners ((bodyy composition p and somatotype) • Low levels of adiposity (body fat) correlated with total time and performance in most disciplines • Proportionally longer segmental lengths contributed to swim outcome • Relatively tall – similar to specialist cyclists, smaller than specialist p swimmers but taller than specialist p endurance runners • Smaller hip and thigh girths associated with better performance • Elite triathletes tend to weigh less than sub-elite / recreational triathletes Ackland et al. 1997, Leake & Carter 1991, Landers et al. 2000, Sleivert & Rowlands 1996
Alterations in morphology of junior triathletes 1997 triathletes, 1997-2011 2011 MALE 1997
MALE 2011
FEMALE 1997
FEMALE 2011
HEIGHT (cm)
175.7
178.4
164.9
167.3
WEIGHT (kg)
67.0
65.8
56.7
52.8
SKINFOLD (sum of 8)
51.5
51.1
73.1
75.8
FLEXED ARM GIRTH (cm) ( )
31.0
29.8
27.7
26.4
ENDOMORPHY
2.4
2.1
3.5
3.3
MESOMORPHY
4.7
3.7
3.5
3.0
ECTOMORPHY
3.1
3.8
2.9
4.1
Longer limbs, smaller bone breadths and girths Landers et al. 2012
What other factors interact with morphology to influence performance? • The impact of morphology on performance can be dependent on: – Race terrain ((hilly y v’s flat cycle y and / or run)) – Environmental conditions (hot v’s cold – and swim may be influenced differently to run) – Wetsuits W t it
What is an optimal morphology for performance? f ? • Swim performance – long limbs – some body fat is believed to be useful to improve buoyancy and reduce hydrodynamic drag
• Cycling performance – partly depends on terrain – Surface area (related to both height and weight) influences performance on a relatively flat course, with lower height and weight (Jobson et al al. 2007) and a larger lower to upper body circumference ratio (Miller & Manfredi 1987) being advantageous
• Run performance – lower body fat improves run performance (Brandon & Boileu 1987) – may also be advantage with lower muscle mass
What is an optimal morphology for TRIATHLON performance? • OD – swim sufficiently fast to be in front pack, cycle efficiently, run fast (men <30 min 10km, women <34 10km) but paced effectively – Influence of body fat in swim can be counteracted by wetsuits
• Non Non-drafting drafting races – each component is important but greater likelihood that a fast run will overcome a slower swim • Therefore, lean / lower body mass is advantageous, particularly p y in heat and hilly y races, BUT not if it compromises swim performance • Currently body composition is more like runners
Example of one female athlete over a season Skinfolds (mm) 85 75 65 55 45 35 25
55 54 53 52 51 50 49 48 47 46 45
21
The ‘ideal’ body fat / muscle mass level will be individual and may need to be achieved progressively
20 19 18 17 16
Mass (kg)
BMI (kg/m2)
Can an athlete get too light / lean? • Yes! • In training, more prone to struggle with swim pool temperature • Can impact heavily on swim component (strength, change body position, hypothermia) • Reduced strength on bike • Increased fatigue in run following a hard bike • Intolerance to colder temperatures
What about age / level of competition? • Junior athletes are still developing p g and do so at different ages – expect differences in body composition and changes over time naturally • Transition from junior to U23, focus on learning how to train effectively, race, self-maintenance, fuel appropriately as first priorities – females may need more leniency on body fat – males often lean but lower muscled – expect that muscle mass will increase over time with strength
• Age group athletes – still important but must be balanced with their physiological capabilities and overall lifestyle
Are there risks associated with achieving optimal ti l morphology? h l ? • Process inappropriate: pp p – Disordered eating behaviours / eating disorder – Low energy availability
• Too rapid a loss of body mass / fat: – Reduced muscle mass / strength – Potential P t ti l tto ‘rebound’ ‘ b d’
• Restrictive diet / insufficient carb diet: – – – –
Inability to train effectively and recover Compromised immune system Increased risk of injury j y and illness Increased risk of micronutrient deficiencies
Female Athlete Triad
ACSM Position Stand – The Female Athlete Triad. 2007.
London 2012 Olympics: triathlete Hollie Avil reveals why she has decided to bring an end to her promising career (The Telegraph, November 2012) That quickly changed when one of the coaches – not mine – said: “You’ll need to start thinking about your weight if you want to run quick, Hollie.” That comment planted a seed in my head that didn’t didn t need to be planted.
Elite Females and Eating Disorder Discussion posted by p y Jodie Swallow If there were any story I could tell talented athletic girls - it is one of forfeited years in the sport I love. I have missed championships and been plagued by injury, I have little doubt this is a consequence of the eating disorder I developed in the early years years. I Follow The Swallow (Blog) – November 19, 2012
"I haven't revealed it before," she says, taking a small breath before t lki about talking b th her pastt eating ti disorders. di d "There "Th is i still till a stigma ti and d so I swing between wanting to talk about it and being ashamed because to me it's still tantamount to weakness. But every week I receive letters from women and young girls. They don't know I've suffered from eating disorders but they explain how they're suffering from these same afflictions. I've got a message in my inbox now from an American girl saying: 'I don't know where to turn, can you help me?' She's a triathlete." Chrissie Wellington
How Many y Triathletes Have (Had) ( ) Eating g Disorders? • Blaydon & Lindner 2002 (n=203 (n=203, included elite and age-group from 1998 World Championships): – Female professionals had higher exercise exercise-dependence dependence and lower eating disorder scores than amateur – 50% of females were rated as having an eating disorder compared d tto 27% off males l
• ACSM position stand: The Female Athlete Triad (2007) – Disordered eating, eating disorders and amenorrhea occur more frequently in sports that emphasise leanness
• DeBate et al. 2002 – triathletes susceptible to a higher prevalence of disordered eating
Eating Disorders • • • •
Anorexia nervosa B li i nervosa Bulimia Binge eating disorder Disordered eating behaviour / eating disorder not otherwise specified
• DSM-IV diagnostic criteria (American Psychiatric Association 1994) Association, • Characterised by SEVERE disturbances in eating behaviour and body image • Many subclinical eating disorders that don’t fit in to these DSM DSM-IV IV diagnostic criteria
Warning Signs for Disordered Eating • Rapid weight loss • Large variations in weight (fluctuations of >1kg) • Weight gain • Relentless, excessive exercise ((inappropriate app op a e training a g–e e.g g when injured) • Mood swings or depressed mood • Avoidance of eating publicly • Bathroom B th visits i it after ft meals l • Preoccupation with food, calories and weight
• Increasing variability in training performance (fatigue, inability to back up training, inability to increase intensity sufficiently) • Distorted association between body mass and body fat changes (e.g. greater body mass change than body fat • Increased self-criticism of b d shape body h / llooks k • Wearing baggy or layered clothing
Treatment of Eating Disorders • Referral to an appropriate pp p multi-disciplinary p y team – – – –
Physician Psychologist / psychiatrist Dietitian experienced in managing eating disorders Coach, trainer, exercise scientist and family should all be involved
• Recovery can take months, or more typically years – Earlyy identification is crucial
• Can recur
Energy Availability Energy gy availability y ((EA)) = Energy gy intake – Energy gy cost of training / competition • Energy availability is the amount of energy remaining to look after physiological needs (cellular maintenance, i thermoregulation, h l i growth, h reproduction, immunity and locomotion) • Low EA <30 kcal/kg FFM (<125 kJ/kg FFM) • Adequate Ad t EA ~ 45 kkcal/kg l/k FFM (190 kJ/k kJ/kg FFM) Loucks & Thuma 2003, Ihle & Loucks 2004
Consequences of Low Energy Availability • Reduced metabolic rate • Reduced endocrine function (leading to amenorrhea) • Lowered testosterone (in males) • Loss of bone density (increased risk of stress fractures) • Compromised immunity • Reduced micronutrient status • Fatigue – Increased risk of injury
When is Low EA Likely to Occur? • Energy gy restriction or additional exercise in order to lose body fat / weight • Inadvertent failure to increase energy intake sufficiently during increased training loads • Eating disorders / disordered eating behaviour • Low EA can be chronic / constant, or may be intermittent
Warning Signs of Low Energy Availability
• Limited weight loss despite the athlete assuring you that they’re ‘trying hard’ • Variable V i bl training t i i capability bilit • Low mood state • Amenorrhoea (in females) • Low libido (in males) • Unusual fatigue • Frequent illness / injury • Remember this can happen in males too!
Assessment of Low Energy Availability • Resting g energy gy expenditure p – Usually suppressed
• 7 day weighed food diary in conjunction with assessment of energy expenditure – Sensewear™ – Training T i i llogs
• Menstrual function • Blood tests – iron stat status, s th thyroid roid ffunction, nction estrogen estrogen, Vitamin D status • Bone density assessment • Fat free mass measurement
Treatment of Low EA • Increased energy gy intake ((e.g. g 350 kcal or 1500 kJ/day) and / or reduction in exercise energy expenditure • Appropriate treatment of underlying eating disorder / disordered eating behaviour (if present) • Optimise O i i calcium l i iintake k and d Vi Vitamin i D status • May require changes in macronutrient content (protein = satiating satiating, high carboh carbohydrate drate / high fibre diet can = appetite suppression) • Training capabilities will return before resumption of normal menstrual function or improvements in bone densityy
BUT...... BUT • Athletes with normal bone densityy can still get g boney y injuries • Amenorrhoea may still occur without low energy availability (not unusual for females to be amenorrhoeic during the most competitive part of the season – but their menstrual function will return in the off season)
And of course.... course • There remain some athletes who don’t lose weight g because they really don’t understand – – – – – – –
Inability to follow instructions appropriately Poor nutrition knowledge Low or intermittent compliance Poor insight into own eating behaviours / serving sizes “I’m an athlete, it’s a licence to eat” Fear of running g out of fuel Reduce energy intake at the wrong times (early in day, recovery periods) then get excessively hungry at other times
What morphology might we see in the future? • Leanness will always be a crucial factor for p performance • Tendency towards lower muscle mass in OD = more ectomorphic p ((linear)) p physique y q
Key Messages for Coaches • Bodyy composition p IS important, p but has to be managed effectively • Get your athletes to see a sports nutrition expert! • Athletes don’t need to be in race shape during the early / heaviest periods of training, nor do they need d tto be b iin th the same race shape h every year (especially in transition from junior to U23) • Some athletes may benefit from GAINING body fat in order to sustain heavy training loads • Set realistic targets and prioritise effective training • Watch for signs of low energy availability