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Fitness, Fatness, Muscle and HealthFitness, Fatness, Muscle and Health
Michael Harrison, PhD
Physical Education Association of Ireland
Annual Conference
October 12th 2013
Waterford Institute of Technology
Thanks
Bruce Wardrop
Exercise Physiologist in the Department of Health, Sport and Exercise Science
And to Paralympics Ireland team at 2008 and 2012 Olympic Games
Is aerobic fitness relevant to
health status and disease risk?
Women Men
CVD Mortality Rates by Fitness:CVD Mortality Rates by Fitness:
Aerobic Center Longitudinal Study (ACLS)Aerobic Center Longitudinal Study (ACLS)
Blair SN, et al. JAMA. 1989;262:2395-2401.
Deaths per 10,000
person-y
ears
Low
Moderate
High
0
5
10
15
20
25
30
0
1
2
3
4
5
6
7
Low
Cardiorespiratory Fitness and Incident Type 2 Cardiorespiratory Fitness and Incident Type 2
Diabetes in 8,633 Healthy Men: Diabetes in 8,633 Healthy Men: ACLSACLSCases per 1,000
man-y
ears
Cardiorespiratory Fitness
Wei M, et al. Ann Intern Med. 1999;130:89-96.
Moderate High
Cardiorespiratory Fitness and Total Digestive Cardiorespiratory Fitness and Total Digestive
System Cancers in 38,801 Healthy Men: System Cancers in 38,801 Healthy Men: ACLSACLS
Peel et al., 2009
28 mL/kg/min
<25 25-28 28-31 38-41 41-45 45-49 >4935-3831-35
Overweight ObeseNormal Weight
0
1
2
3
4
5
6
Fitness Fitness -- Fatness and CVD Fatness and CVD
Mortality in Men: Mortality in Men: ACLSACLSRisk for Death
Wei M, et al. JAMA. 1999;282:1547-1553.
Unfit
Fit
5.05.0
1.61.61.51.5
4.54.5
Reference
3.13.1
Other risk factors
Relative risk (RR) of CVD mortality associated with a range of risk factors in overweight men
� Low fitness RR = 3.0
� Diabetes RR = 2.3
� Smoker RR = 1.8
� High cholesterol RR = 1.75
� Hypertension RR = 1.6
Wei et al., 1999
Cardiorespiratory fitness is associated with lower likelihood ofCardiorespiratory fitness is associated with lower likelihood of
the metabolic syndrome in European adolescents the metabolic syndrome in European adolescents
Results of the Healthy Lifestyle in Europe by Nutrition and AdolResults of the Healthy Lifestyle in Europe by Nutrition and Adolescence escence
(HELENA ) study(HELENA ) study
Least fit adolescents were 4- 8
times more likely to have
metabolic syndrome profile
compared to most fit children
Artero et al. (2011)
www.helenastudy.com
Aerobic fitness values
Maximum oxygen uptake (VO2max)
--our greatest ability to take in oxygen our greatest ability to take in oxygen (lungs)(lungs), ,
transport it in our bloodstream transport it in our bloodstream (red blood cells), (red blood cells),
circulate it to the muscles circulate it to the muscles (heart) (heart) and and
burn it in the muscles with glucose burn it in the muscles with glucose (mitochondria) (mitochondria)
to produce energyto produce energy
A.k.a. A.k.a. Cardiorespiratory fitnessCardiorespiratory fitness
Aerobic fitness values
Typical values (mL/Typical values (mL/kg/kg/min)min)
MenMen WomenWomen
Elite athleteElite athlete 80 80 7272
Games playerGames player 55 55 –– 6060 45 45 –– 5050
Non sporting adultsNon sporting adults
30 30 –– 39 years39 years 41 41 –– 4747 34 34 –– 4040
50 50 –– 59 years59 years 35 35 –– 42 42 25 25 –– 3030
Aerobic fitness
Aerobic fitness values are sometimes Aerobic fitness values are sometimes
expressed in METS expressed in METS
(multiples of resting metabolic rate)(multiples of resting metabolic rate)
1 MET = VO1 MET = VO22 of 3.5 mL/kg/minof 3.5 mL/kg/min
Aerobic fitness values
Typical values Typical values -- mL/kg/min mL/kg/min (METS)(METS)
MenMen WomenWomen
Elite athleteElite athlete 80 80 (23)(23) 72 72 (20)(20)
Games playerGames player 5555-- 60 60 (16(16--17)17) 4545-- 50 50 (13(13--14)14)
Non sporting adultsNon sporting adults
30 30 –– 39 years39 years 4141-- 47 47 (12(12--14)14) 3434-- 41 41 (10(10--12)12)
50 50 –– 59 years59 years 3535-- 42 42 (10(10--12)12) 2525-- 3030 (7(7--9)9)
Table 1. Normative Values for Maximal Oxygen Uptake (mL/kg/min)
Age
Percentile* 20–29 30–39 40–49 50–59 60–69
Men
90 54.0 52.5 51.1 46.8 43.2
80 51.1 48.9 46.8 43.3 39.5
70 48.2 46.8 44.2 41.0 36.7
60 45.7 44.4 42.4 38.3 35.0
50 43.9 42.4 40.4 36.7 33.1
40 42.2 41.0 38.4 35.2 31.4
30 40.3 38.5 36.7 33.2 29.4
20 39.5 36.7 34.6 31.1 27.4
10 35.2 33.8 31.8 28.4 24.1
Women
90 47.5 44.7 42.4 38.1 34.6
80 44.0 41.0 38.9 35.2 32.3
70 41.1 38.8 36.7 32.9 30.2
60 39.5 36.7 35.1 31.4 29.1
50 37.4 35.2 33.3 30.2 27.5
40 35.5 33.8 31.6 28.7 26.6
30 33.8 32.3 29.7 27.3 24.9
20 31.6 29.9 28.0 25.5 23.7
10 29.4 27.4 25.6 23.7 21.7
VO2max Norms for the
Cooper Institute used to
categorise participants in
the Aerobics Centre
Longitudinal Studies
Those below the 20th
percentile in specific age and gender categories
are defined as LOW FIT
in these studies
Risk reduction across different fitness categories
Health benefits obvious with aerobic fitness levels above
� 28 mL/kg/min (8 METS) for older men
� 21 mL/kg/min (6 METS) for older women
There is a 13-15% reduction in risk for every 3.5 ml/kg/min (1 MET) increase in VO2max
This equates to
•1 km/h increase in maximum running speed
(Kodama et al., 2009)
Other risk factorsOther risk factors
This 13This 13--15% risk reduction (for every 1 MET 15% risk reduction (for every 1 MET
increase in fitness) is equivalent to a increase in fitness) is equivalent to a
�� 7 cm reduction in waist circumference7 cm reduction in waist circumference
�� 5 mmHg reduction in systolic blood pressure5 mmHg reduction in systolic blood pressure
�� 0.5 mmol/L reduction in total cholesterol0.5 mmol/L reduction in total cholesterol
What is acceptable aerobic fitness What is acceptable aerobic fitness
for children and adolescents?for children and adolescents?
�� Norm vs CriterionNorm vs Criterion--referenced standardsreferenced standards
�� Fitnessgram is now linking aerobic fitness to Fitnessgram is now linking aerobic fitness to
presence of the Metabolic Syndromepresence of the Metabolic Syndrome
i.e. trying to specify target VOi.e. trying to specify target VO22max levels for max levels for
children and adolescents that offer protection children and adolescents that offer protection
against metabolic syndromeagainst metabolic syndrome
Fitnessgram
Aerobic fitness testsAerobic fitness tests
��PACER (20 MST)PACER (20 MST)
��One mile run testOne mile run test
Complex formula then predicts VOComplex formula then predicts VO22max based on max based on
��Test scoreTest score
��BMIBMI
��Age and genderAge and gender
www.fitnessgram.net
FitnessgramFitnessgram
Three zones createdThree zones created
1.1. Healthy Fitness ZoneHealthy Fitness Zone
2.2. Needs Improvement Needs Improvement –– Some RiskSome Risk
3.3. Needs Improvement Needs Improvement –– High RiskHigh Risk
www.fitnessgram.net
Fitnessgram standards for aerobic fitness
www.fitnessgram.net
Parent Fitnessgram Report
European standards for aerobic fitness
EU NORMS have been developed as part of
HELENA study and these were used to compare Irish children as part of the DCU “Aviva Schools Fitness Challenge (Beat the Bleep)” initiative
www.helenastudy.comwww.helenastudy.com
European 20 Metre Shuttle Test Norms by Age and Gender -Results of the Healthy Lifestyle in Europe by Nutrition and Adolescence
(HELENA ) study
Ortega et al., 2011, BMJ
How can we increase aerobic fitness?How can we increase aerobic fitness?
Exercise for aerobic fitnessExercise for aerobic fitness
Current guidelines for increasing aerobic fitnessCurrent guidelines for increasing aerobic fitness
�� FF 3 3 –– 5 times per week5 times per week
�� II Vigorous exercise Vigorous exercise (65 (65 –– 85% Heart Rate Reserve)85% Heart Rate Reserve)
�� TT 20 20 –– 60 min per session60 min per session
�� TT Rhythmic exercise, large muscle groupsRhythmic exercise, large muscle groups
What is HIT ?
High Intensity Training (HIT or HIIT)
High Intensity Interval Exercise (HIIE)
Brief periods of very high intensity exercise interspersed with low intensity exercise or rest
The total volume of exercise (in min) is low
What is HIT ?
Gibala protocol
� F 3 sessions per week
� I all out
� T 4 – 6 x 30 sec, ~ 4 min recovery
� T sprint cycling or running
Weekly training time is therefore ~ 10 min
What is HIT ?
Gibala 2 protocol
� F 3 sessions per week
� I near all out (90% of HRmax)
� T 10 x 60 sec, 60 sec recovery
� T sprint cycling or running
Weekly training time is therefore ~ 10 min
What is HIT ?
Timmons protocol (BBC Horizon programme, The Truth About Exercise)
http://www.youtube.com/watch?v=v7-h_w7bJrU
� F 3 sessions per week
� I all out
� T 3 x 20 sec, 60 sec recovery
� T sprint cycling
Weekly training time is therefore ~ 3 min
High Intensity Interval TrainingHigh Intensity Interval Training
Effect on Endurance PerformanceEffect on Endurance Performance
• 3 HIT/wk for 2 weeks
• Endurance test - exercise to
exhaustion at 80% VO2max
• Length of time that exercise
could be maintained ↑ from 26-
51 min
J Appl Physiol 98: 1985-1990, 2005
High Intensity Interval Training vs. High Intensity Interval Training vs. Continuous Endurance Training Continuous Endurance Training
ResultsResults
Gibala et al, J Physiol 575(3) 901-911, 2006
• HIT (n=8) or CET (n=8)
• 6 sessions in 14 d
• 4-6 x 30 s all out cycling with 4 min recovery (2.5 hours training)
• OR 120 min continuous cycling (10.5 hours training)
• Similar improvements in endurance performance
HIT CET
Influence of 6 sessions of short duration very high intensity exercise on glucose
tolerance and insulin action in young men
Babraj, Timmons et al., 2009
Exercise
3 times weekly for 2 weeks
4-6 x 30 sec sprints
4 min recovery between sprints
12-18 min exercise in total
What variation exists What variation exists
between individuals in terms of between individuals in terms of
response to training?response to training?
Changes in VO2max with training in identical twins
Bouchard, 1992
Influence of a 20 week training programme on VO2max
Results from the HERITAGE family study (n=481)
(Bouchard et al., 1999)
Average increase
384 ml O2/min (15%)
0-8%
8-16%
16-24%
24-32%
32-40%>40%
↓
Genetic factors in exercise training response
60% of the variation in the response of VO2max to training can be accounted for by genetic factors
At least 58 different genes have been identified that
may influence aerobic fitness response to exercise training
Should those who have a Should those who have a
preponderance of preponderance of ““unresponsive unresponsive
genesgenes”” bother with exercise?bother with exercise?
Early work suggests that the same cardiovascular disease risk reduction occurs in those with “high fitness response” and “low fitness response”genes
Chomistek, I-M Lee et al (2013)
Everybody benefits health wise from exercise
Some benefit fitness wise more than others
Do some find exercise particularly difficult?
Are there “lazy” genes?
TIGER studyTIGER study““Training Intervention and Genetics of Exercise ResponseTraining Intervention and Genetics of Exercise Response””
www.tigerstudy.orgwww.tigerstudy.org
University of Houston students at obtain academic University of Houston students at obtain academic
credit for adherence to an exercise programmecredit for adherence to an exercise programme
TIGER StudyTIGER Study
TargetTarget
�� 3 days per week over 30 weeks3 days per week over 30 weeks
�� 6565--85% heart rate reserve (i.e. vigorous)85% heart rate reserve (i.e. vigorous)
�� 40 minutes with 25 min in target heart rate zone40 minutes with 25 min in target heart rate zone
Retention over one semester Retention over one semester –– 68%68%
Retention between semesters only Retention between semesters only -- 20%20%
Lessons from the TIGER studyLessons from the TIGER study
Factors distinguishing adherers from Factors distinguishing adherers from
dropouts:dropouts:
�� Higher BMI and waist circumferenceHigher BMI and waist circumference
�� Lower exercise intensity and shorter durationLower exercise intensity and shorter duration
�� Range of genetic markersRange of genetic markers
But notBut not
�� Aerobic fitnessAerobic fitness
�� GenderGender
Lessons from the TIGER studyLessons from the TIGER study
Genetic factorsGenetic factors
Variations in the Variations in the HTR2AHTR2A, , HTR2CHTR2C and and DRD4DRD4 genes genes
influence exercise intensity and adherence influence exercise intensity and adherence
These variations relate to the These variations relate to the dopaminedopamine and and
serotoninserotonin pathways in the brain which also relate pathways in the brain which also relate
to pleasure, reward and addictionto pleasure, reward and addiction
Results of other genetic studiesResults of other genetic studies
Other studies suggest a considerable genetic contribution to physical activity involving genes that regulate
� Brain pleasure and reward circuits
� Muscle function
� Glucose control
How important is body fat ?How important is body fat ?
Is it possible to be fat and fit?Is it possible to be fat and fit?
BMI in IrelandBMI in Ireland
Adult Population
UnderweightUnderweight 1%1%
Normal weightNormal weight 35%35%
OverweightOverweight 39%39%
ObeseObese 25%25%
SLAN, 2007
64%
BMI in Children and Adolescents
9 year olds
19% Overweight + 7% Obese = 26%
(Growing Up in Ireland, 2011)
13-17 year olds
11% Overweight + 8% Obese = 19%
(Irish Universities Nutrition Alliance, 2008)
BMI = 20.7
% fat = 18
BW=64 kg
LBM = 49 kg
BMI = 24.9
% fat = 40
BW=80 kg
LBM = 45 kg
BMI = 20.7
% fat = 32
BW=62 kg
LBM = 39 kg
http://youtu.be/BQdH_1eHBWw
Relative risk of developing diabetes, according
to indices of fatness at baseline
Wang et al., 2005
Male and female – type obesity
Overweight ObeseNormal Weight
0
1
2
3
4
5
6
Fitness Fitness -- Fatness and CVD Fatness and CVD
Mortality in Men: Mortality in Men: ACLSACLSRisk for Death
Wei M, et al. JAMA. 1999;282:1547-1553.
Unfit
Fit
5.05.0
1.61.61.51.5
4.54.5
Reference
3.13.1
Change to health from exercise Change to health from exercise
in absence of weight lossin absence of weight loss
� Cardiorespiratory fitness
� Blood pressure
� Blood vessel development and function
� Blood lipids (but not total or LDL-cholesterol)
� Blood glucose and insulin sensitivity
� Mood and cognitive function
Appropriate target
Weight loss OR Fitness ?
Fierce debate underway
Does muscle mass and strength
relate to health?
Muscle and health
Muscle secretes a wide variety of insulin-sensitising and anti-
inflammatory messengers (myokines) into the blood that
influence fat, liver and brain cells
Endocrine Organ ?
Strength and fitness both inversely associated with the metabolic syndrome: ACLS data
Jurca et al (2004)
Muscle and healthMuscle and health
HELENA study
Standing Long Jump and handgrip strength both predict insulin sensitivity in adolescents
Jiménez-Pavon et al. (2011)
Muscular fitness is associated with lower likelihood of the Muscular fitness is associated with lower likelihood of the
metabolic syndrome in European adolescents metabolic syndrome in European adolescents
Results of the Healthy Lifestyle in Europe by Nutrition and Results of the Healthy Lifestyle in Europe by Nutrition and
Adolescence (HELENA ) studyAdolescence (HELENA ) study
Adolescents with lowest
muscular fitness were 5- 8
times more likely to have
metabolic syndrome profile
compared to most fit children
Artero et al. (2011)
www.helenastudy.com
BMI = 20.7% fat = 32BW=62 kgLBM = 39 kg
Problems for the future?
Summary
� Aerobic fitness is vital for health
� The greatest benefit appears to occur when we
move individuals out of the lowest fitness
categories
� Aerobic fitness may be as important or more
important than obesity in terms of reducing risks
� High intensity interval training may be a novel
way of improving aerobic fitness
Summary
� There is considerable variation in terms of the
response to aerobic exercise training, there are
responders and non-responders, with multiple
genes involved
� There are individuals who find exercise more
difficult than their peers, with genetic factors
involved
Summary
� The use of BMI has many limitations. In particular it “hides” risks associated with low muscle mass and high levels of central obesity
� Muscle mass and muscle strength are associated with better metabolic health both in adults and children. Strength training should be encouraged for all