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