20 years 80 years - Fysioterapeuterna · Per Aagaard Institute of Sports Science and Clinical...

1

Loss in muscle mass and

neuromuscular function with aging

- Use of exercise as a countermeasure

Per Aagaard

Institute of Sports Science and Clinical Biomechanics,

University of Southern Denmark / [email protected]

Department of Physiotherapy, Institute of Neuroscience & Physiology,

Sahlgrenska Academy, University of Göteborg

“Träning för äldre”

Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 2013

20 years 80 years20 years 80 years

Aging ….. the continuum of life



Presentation Outline

Changes in muscle mass and

neuromuscular function with aging

Effects of strength training in elderly on...

- Muscle mass and neuromuscular function

- Mechanical muscle function (strength, RFD, Power)

- Rehabilitation in patients

- Functional capacity



2



Age-related changes in neuromuscular function

Loss of muscle mass with aging: Sarcopenia

Paolo Caserotti, NIH Besthesda & IOB-SDU

Vandervoort, Muscle & Nerve 25, 2002

Parise & Yarasheski,

Curr Opin Clin Nutr Metab Care, 2000

31 yr (m)

66 yr (m)

73 yr (f)

85 yr (f)

Loss of muscle mass with aging:

sarcopenia

Reduced muscle cross-sectional area

( 40% between the age of 20 and 80 yrs)

The decline seems to start in early

adulthood and accelerate after the age of

50 years

content of non-contractile tissue such as

intramuscular fat and connective tissue

Cross-sectional images of the QUADRICEPS muscle (MRI)

62-yr old woman 81-yr old woman

Caserotti, Aagaard et al 2008


Parise & Yarasheski,

Curr Opin Clin Nutr Metab Care, 2000

31 yr (m)

66 yr (m)

73 yr (f)

85 yr (f)

Loss of muscle mass with aging:

sarcopenia

Reduced muscle cross-sectional area

( 40% between the age of 20 and 80 yrs)

The decline seems to start in early

adulthood and accelerate after the age of

50 years

content of non-contractile tissue such as

intramuscular fat and connective tissue

"Sarcopenic obesity"

3

Reduction in muscle fiber size with aging

Young

subject

Old

subject

VL stainings courtesy

JL Andersen

CMRC 2004

courtesy C Suetta

Sarcopenia (loss of muscle mass)

Sarcopenia is significantly associated with... 3-4 times greater risk of physical disability 2-3 times greater risk of balance abnormality

2-3 times greater risk of falls Baumgartner RN 1998, 1999

In frail elderly persons with advanced sarcopenia

but without circulatory or pulmonary diseases,

muscle weakness is typically more limiting for

daily functioning than aerobic fitness.

Photo courtesy

Charlotte Suetta

4

SARCOPENIA

Reduced Muscle Mass with Ageing

The result of aging per se

or due to reduced

physical activity

/ increased inactivity?

Studies in ageing Master Athletes

Korhonen et al, J Appl Physiol 2006

Reduced Muscle Fiber size with ageing

Muscle fiber size in young vs aging sprinters:

trend for decreased fiber area with increase in age

Type I fibers Type IIA

Type IIAX Type IIX

SARCOPENIA

Reduced Muscle Mass with Ageing

The result of aging per se

or due to reduced

physical activity

/ increased inactivity?

Muscle size is reduced also in

physically active individuals

... aging does play a role

5


Loss of spinal motor neurons,

CNS reorganization



Spinal motor neurons

reduced number of motor

neurons in the spinal cord

25% average loss of spinal motor

neurons (lumbospinal segments L1-S3)

from 20 yrs to 90 yrs of age

Tomlinson & Irving 1977

several subjects > 60 yrs

showing ~ 50% less MN's

compared to 20-40 yrs old


Brainmotor cortex

cerebellum

Spinal

cord

Muscle

spinal motor neurons

Neural factors - neuromuscular function

spinal motor neurons, nerve axons, motor units

Reduced muscle mass, muscle CSA

Total fiber number Muscle fiber size

Muscle strength

Motor unit number

# Spinal motor neurons

Motor unit size

innervation ratio (# fibers/neuron)

Motor Unit remodeling


Neuromuscular changes related to aging

Spinal motor neurons

reduced number of motor

neurons in the spinal cord

25% average loss of spinal motor

neurons (lumbospinal segments L1-S3)

from 20 yrs to 90 yrs of age


several subjects > 60 yrs

showing ~ 50% less MN's

compared to 20-40 yrs old


Brainmotor cortex

cerebellum

Spinal

cord

Muscle


Neural factors - neuromuscular function

spinal motor neurons, nerve axons, motor units

# motor neurons = # motor units

at increasing age

ongoing process of

denervation

of skeletal muscle fibers late in life

Vandervoort 2002, McComas 1996

AJ McComas: Skeletal muscle

- form and function, 1996



Muscle strength

Motor unit number


Motor unit size






Muscle fibers

motor axon

6

# motor neurons = # motor units

at increasing age

ongoing process of

denervation and reinnervation

of skeletal muscle fibers late in life

evidenced by

- histological findings of fiber type grouping

- elevated coexpression of MHC isoforms

- preferential atrophy of type II muscle fibers

- very large MUAPs, indicating innervation ratio

Vandervoort 2002, McComas 1996AJ McComas: Skeletal muscle

- form and function, 1996



Muscle strength

Motor unit number


Motor unit size






Muscle fibers

motor axon

Motor unit number


Motor unit size



Reduced muscle mass cross sectional area

Total fiber number Muscle fiber size (pref. type II)

Muscle strength

SUMMARY - Muscular and Neuronal changes induced by Ageing

Aagaard et al, Scand J Med Sci Sports 20, 2010

Motor unit number


Motor unit size



Reduced muscle mass cross sectional area

Total fiber number Muscle fiber size (pref. type II)

Muscle strength

SUMMARY - Muscular and Neuronal changes induced by Ageing

Aagaard et al, Scand J Med Sci Sports 20, 2010

CONSEQUENCES

FOR MECHANICAL

MUSCLE

PERFORMANCE?

7


Impairments in mechanical muscle function



Decreased Muscular Strength With Aging

Isometric muscle strength

Is preserved to ~50-60 yrs of age

(cross sectional data)

Decreases at a rate of 1-1.5%

per year from 60-65th year

Substantial individual differences !

Spirduso, Physical dimensions of aging, 1995

Vandervoort & McComas 1986

Spirdoso 1995

Decreased Muscular Strength With Aging

Isometric muscle strength

Is preserved to ~50-60 yrs of age

(cross sectional data)

Decreases at a rate of 1-1.5%

per year from 60-65th year

Substantial individual differences !

Spirduso, Physical dimensions of aging, 1995

Vandervoort & McComas 1986

Spirdoso 1995

Peak Power

Mean Power

Peak Power

Mean Power

trained untrained

Pearson, Harridge et al;

Med Sci Sports Exerc 2002

Maximal Muscle Power - elite master weightlifters

8


Peak Power

Mean Power

Peak Power

Mean Power

trained untrained



Trained (closed circles) and

untrained (open circles)

individuals demonstrated

similar age-related decline

rate in peak power (1.3%

vs 1.2% per year, respectively)

Peak Power

Mean Power

20 years

Peak Power

Mean Power

trained untrained



Trained (closed circles) and

untrained (open circles)

individuals demonstrated

similar age-related decline

rate in peak power (1.3%

vs 1.2% per year, respectively)


Maximal leg extensor

muscle power assessed

by force plate analysis

Maximal counter-movement

jumps: Stretch-Shortening

Cycle muscle power Caserotti, Aagaard et al EJAP 2001,

Thorlund, Aagaard et al SJMSS 2008,

Edwén, Aagaard et al SJMSS 2013

Maximal SSC Muscle Power - Women vs Men?

Cecilia Edwén

et al SJMSS 2013

9

Is maximal muscle power and rapid force

capacity (RFD: rate of force development)

important in elderly individuals ?

Is maximal muscle power and rapid force

capacity (RFD: rate of force development)

important in elderly individuals ?

YES !

Functional performance in the elderly is influenced by maximal mechanical muscle power

Men

Women

r=.83***r=.45

r=.86***r=.91***

r=.93***r=.58*

*P<0.05

***P<0.001

Leg extensor power (W/kg) Leg extensor power (W/kg)

Sta

ir-c

lim

bin

g s

pe

ed

(m

/s)

Wa

lkin

g s

pe

ed

(m

/s)

Ch

air

ris

ing

sp

ee

d (

s-1

)

Bassey et al, 1992

Nursing Home residents

Functional capacity in the elderly is strongly

influenced by maximal mechanical muscle power

10

Can the age-related loss in muscle mass, and decrease in

muscle strength and power be slowed or reversed by training ?



Can the age-related impairment in neural function

be effectively compensated by training ?

Brainmotor cortex

cerebellum

Spinal

cord

Muscle



Can the age-related impairment in neural function

be effectively compensated by training ?

YES !

.... by means of strength / resistance training

11




- Effects of strength training in old adults

Adaptive alterations in muscle size,

neuromuscular activity

and mechanical muscle function

Narici et al: Training-induced changes in elderly muscle,

J. Musculoskel. Neron. Interact. 4, 2004

Ferri 2003

Frontera 1988

Häkkinen 1998

Harridge 1999

Häkkinen 1985

Jones & Rutherford 1987

Narici 1996

Percentage increases in muscle CSA and Maximal muscle

strength (MVC) with Strength Training in old vs young individuals

85 year old discharged geriatric patients

12 weeks of resistance exercise

- isolated knee extensor exercise

- 3 session per week,

- 3 sets x 8 rep,

- training loads >70% 1 RM

Kryger & Andersen,

Scand J Med Sci Sports 2007

Heavy-resistance strength training induces muscle fiber growth

also in very old individuals (85-97 yrs, mean age 89 ± 3 yrs)

12

Kryger & Andersen



also in very old individuals (85 yrs)

Mean age 89 ± 3 yrs (n=11), 3 sessions weekly, 12 wks

Results

Type IIa fibre CSA 22% *

Quadriceps strength 40-45% *

Chair rising time (5 reps) 30% faster *

Maximal walking speed 25% faster *

* p < 0.05

85 year old discharged geriatric patients

12 weeks of resistance exercise

knee ext. 3 x weekly, 3 x 8 rep, >70% 1 RM

Kryger & Andersen,



also in very old individuals (85-97 yrs, mean age 89 ± 3 yrs)

Increases in muscle fibre size in older individuals following

high-intensity dynamic leg strength training. Based on

biopsy samples obtained from vastus lateralis

Study

Muscle fiber size

increase (%)

Type I Type II

Frontera et al., J. Appl.

Physiol. 64, 1988

34

26

7

20

8

5

Häkkinen et al.

J. Gerontol. 53B, 1998 23

27

Fiatarone-Singh et al.

Am. J. Physiol. 277, 1999

5

-12

Hunter et al., J. Appl.

Physiol. 86, 1999

14

23

Hikida et al.

J. Gerontol. 55, 2000

46

43


>

<

<

Charette et al., J. Appl.

Physiol. 70, 1991

Grimby et al., J. Appl.

Physiol. 73, 1992

13

Maximal Explosive Muscle Strength

1000

2000

3000

4000

5000

0

0.20 0.4 0.6 0.8

Time (seconds)

Fo

rce

(N

)

RFD =

Force / Time

F

orc

e

Time

max Force

Rate of Force Development (RFD)Maximal Explosive Muscle Strength

1000

2000

3000

4000

5000

0

0.20 0.4 0.6 0.8

Time (seconds)

Fo

rce

(N

)

RFD =

Force / Time

F

orc

e

Time

max Force

Rate of Force Development (RFD)

Contractile Rate of Force Development (RFD) Rapid Force Capacity (Explosive muscle strength)

Aagaard et al, J Appl Physiol 2002

Clarckson et al 1981, Häkkinen et al 1995,

Izquierdo et al 1999, Barry et al. 2005,

Korhonen et al 2006, Klass et al 2008,

Suetta, Kjær, Aagaard et al 2009

RFD Contractile Rate of Force Development

Rapid force capacity (RFD) in elderly vs young individuals

Contractile RFD is substantially reduced in

healthy aging individuals compared to young

individualsClarckson et al. 1981, Häkkinen et al. 1995,

Izquierdo et al. 1999, Korhonen et al. 2006,

Klass et al 2008, Suetta, Hvid et al 2008

RFD RFD Contractile Rate of Force Contractile Rate of Force DevelopmentDevelopment

Maximal explosive muscle strength in elderly vs young individuals

1000

2000

3000

4000

5000

0

0.20 0.4 0.6 0.8

Time (seconds)

Fo

rce

(N

)

RFD =RFD =

Force / Time

F

orc

e

Time

max Force

m. quadriceps femoris

Young (24 yr, n=9)

Old (67 yr, n=11)

Suetta, Kjær, Aagaard et al,

J Appl Physiol 2009

* Y < O (p<0.05)

*

*

0-30 ms 50 ms

20

15

10

0

RFD (Nm/s/kg)

Young (67 yr, n=9)

Old (24 yr, n=11)

0-30 ms 50 ms

20

15

10

0

0-30 ms 50 ms

20

15

10

0

0-30 ms 50 ms

20

15

10

0

What is the effect of strength

training on maximal contractile

rate of force development (RFD)

in elderly individuals?

14

Subjects

Mean age 62.7 (SD 2.2) and 81.8 (SD 2.7) yrs

n = 20 + 20 con n = 12 + 13 con

Caserotti, Aagaard et al, SJMSS 2008

Explosive-type resistance training in the old (60 yrs) and the very old (80 yrs)

Subjects

Mean age 62.7 (SD 2.2) and 81.8 (SD 2.7) yrs Duration, frequency

12 weeks, twice a week Familiarization period

2 wks with lower training loads (50% 1RM),

and reduced movement velocity Progressive load adjustment:

Every two weeks with a new estimated 1RM (5-RM test) Exercises (bilateral)

Horizontal leg press, knee extension, calf rise, incline leg

press, leg curl - slow ECC, rapid (max acc) CON actions Exercise intensity and reps

75-80% 1RM loads, 8-10 reps, 4 sets each exercise Caserotti,

Aagaard et al, SJMSS 2008

Explosive-type resistance training in the old (60 yrs) and the very old (80 yrs)

Explosive-type resistance training in the old and the very old

Unilateral isometric leg press test device

Static leg extensor MVC

Paolo Caserotti

15

Fig.2 Representative Maximal Voluntary Contraction recorded during a unilateral isometric leg press

test. F50, F100, F300 and F500 represent the force values recorded after 50, 100, 300 and 500

milliseconds, respectively. Fpeak is the maximal force recorded during this trial.

New

ton

F50

6000

0

200

400

600

800

1000

1200

1400

1600

1800

Fpeak

F500

F300

F100

Force

Time (msec)1000 400030002000 50000

Start of

contraction

New

ton

F50

6000

0

200

400

600

800

1000

1200

1400

1600

1800

Fpeak

F500

F300

F100

Force

Time (msec)1000 400030002000 50000

New

ton

F50

6000

0

200

400

600

800

1000

1200

1400

1600

1800

Fpeak

F500

F300

F100

Force

Time (msec)1000 400030002000 50000

F50

6000

0

200

400

600

800

1000

1200

1400

1600

1800

Fpeak

F500

F300

F100

Force

Time (msec)1000 400030002000 50000

0

200

400

600

800

1000

1200

1400

1600

1800

Fpeak

F500

F300

F100

Force

Time (msec)1000 400030002000 50000

Start of

contraction

Paolo Caserotti


0

30

40

50

60

70

80

*

*

0 week (pre) 12 weeks (post)

TG60CG60TG80CG80

Contractile Rate of Force Development

Leg Press MVC; 0-200 ms

TG60CG60TG80CG80

+18%

+51% 60 yrs old

80 yrs old

TG60CG60TG80CG80

P<0.05 within-group changes

*

(n=20)

(n=20)

(n=12)

(n=13)


marked increases in rapid force capacity (RFD)

Caserotti, Aagaard et al, Scand J Med Sci Sports Exerc 2008

0

30

40

50

60

70

80

*

*


TG60CG60TG80CG80



TG60CG60TG80CG80Diff = 43%

p < 0.001

60 yrs old

80 yrs old

TG60CG60TG80CG80


*

(n=20)

(n=20)

(n=12)

(n=13)




16

0

30

40

50

60

70

80

*

*


TG60CG60TG80CG80



TG60CG60TG80CG80

60 yrs old

80 yrs old

TG60CG60TG80CG80


*

(n=20)

(n=20)

(n=12)

(n=13)

Diff = 43%

p < 0.001

Diff = 15% n.s.




0

30

40

50

60

70

80

*

*


TG60CG60TG80CG80



TG60CG60TG80CG80

60 yrs old

80 yrs old

TG60CG60TG80CG80


*

(n=20)

(n=20)

(n=12)

(n=13)

Diff = 43%

p < 0.001

Diff = 15% n.s.

12 wks of explosive-type

HRST in 80 yr old

20 years younger!




TG 60 TG80

MVC (maximal strength) +22%* +28%*

RFD (rapid force capacity) +18%* +51%*

SSC muscle power +5%* +6%* (CMJ force plate)

Rapid muscle power +12%* +28%* (Power rig)

* pre vs post (p<0.05)




17




- Effects of strength training in elderly patients

Adaptive alterations in muscle size,

neuromuscular activity

and functional capacity

Effects of strength training in

elderly patients

Well, does the need exist?

Strength training is the only exercise modality

known to effectively increase muscle mass

Substantial muscle atrophy

is observed with long-term

disuse, such as in

- hip or knee arthrosis,

- COPD,

- type 2 diabetes

- and many other types of

chronic disease...


elderly patients


Significant muscle atrophy

may be observed in

response to acute

short-term disuse

(4-14 days immobilization)

... recovery is more

difficult to achieve in

old individuals!

Quadriceps muscle CSA

(24 yrs)

(67 yrs)

Hvid, Aagaard, Suetta et al,

J Appl Physiol 2009

18


elderly patients


Significant muscle atrophy

may be observed in

response to acute

short-term disuse

(4-14 days immobilization)

... recovery is more

difficult to achieve in

old individuals!

Suetta, Aagaard et al, J Physiol 2013

Young

Old

(24 yrs)

(67 yrs)

Effects of resistance training rehabilitation on

muscle mass and functional capacity in elderly

hip replacement patients

Suetta, Aagaard et al, J Appl Physiol 2004

MVC

Biopsy

UL-scan

0 5 12 Wks

+ unilateral Electrical Stimulation (n=10) - ES

S

U

R

G

E

R

Y

+ unilateral Strength Training (n=10) - ST

Standard Rehabilitation (n=8) - SR

60 yrs

-1

MVC

Biopsy

UL-scan

MVC

Biopsy

UL-scan

MVC

Rehabilitation of muscle mass and neuromuscular function

following Hip Replacement Surgery in old adults (60-86 yrs)

by use of resistance training

Suetta, Aagaard, Kjaer et al, J Appl Physiol 2004

19

Strength Training protocol

Strength exercises - heavy loads

unilateral heavy-resistance strength training - Affected Limb

Leg-

press

Knee-

extension

Wks 1-2: 3x10 (20 RM), Wks 3-4: 3x12 (15 RM), Wks 5-6: 4x10 (12 RM)

Wks 7-8: 5x8 (8 RM), Wks 9-10: 4x8 (8 RM), Wks 11-12: 3x8 (8 RM)


Rehabilitation from elective Hip replacement Surgery by use of Strength Training

*#

CS

A(m

m²)

0

3000

4000

5000

6000

Pre 5wk 12wkPre 5wk 12wkPre 5wk 12wk

*

§**

*#

*#

CS

A(m

m²)

0

3000

4000

5000

6000


*

§**

CS

A(m

m²)

0

3000

4000

5000

6000


*

§**

Changes in anatomical

Muscle Cross Sectional Area (CT-scanning)

CS

A

(%)

0

90

92

94

96

98

100

102

104

106

108

110

S - CSA %

E - CSA %

K - CSA %

*

Pre 5w 12w

#


ST ES SR

ST

SR ES

Standard Rehab

Electro Stimulation

Strength Training

ST

SR

ES


Changes in maximal muscle strength (isometric MVC)

To

rqu

e (

Nm

)

0

20

40

60

80

100

120

140

160

180

strength-op

elstim-op

kontrol-op

Pre 5w 12w Pre 5w 12w

*

Isometric strength 60°

Suetta et al, J Appl Physiol 2004

To

rqu

e (

Nm

)

0

20

40

60

80

100

120

140

160

strength-op

elstim-op

kontrol-op

#

Pre 5w 12w

RT ES SR resistance electrical standard

training stimulation rehabilitation

12 wk > pre (p<0.05); # 5 wk < pre,12 wk (p<0.05) *

+24%

-22%


20

Changes in neuromuscular activity (muscle EMG)

and Rapid Force Capacity (RFD)


Heavy-resistance strength training

Concurrent increases in

maximal RFD and neuromuscular activity (iEMG)

in elderly individuals

Training induced changes inexplosive muscle strength (RFD)

Adaptive responses in aged individuals

Häkkinen & Häkkinen 1995 (age 50, 70 yrs, gender F, M)

Häkkinen et al. 1998 (age 40, 60 yrs, gender F, M)

Häkkinen et al. 2001 (age 63 yrs, gender F)

Suetta et al. 2004 (post hip replacement surgery, 60-86 yrs)

Barry et al. 2005 (age 60-79 yrs, gender F, M)

100 Nm

-2500

2500

3000

-3000

-4000

4000

position

Moment

EMG VL

EMG VM

EMG RF

Time (msec)

0 1000 2000 3000 4000 5000

uVolt

uVolt

uVolt

Time (msec)

0 1000 2000 3000 4000 5000

slow concentric contraction

pre training

slow eccentric contraction

pre training

Neural drive m. quadriceps

Aagaard et al., J. Appl. Physiol. 2000















100 Nm

-2500

2500

3000

-3000

-4000

4000

position

Moment

EMG VL

EMG VM

EMG RF

Time (msec)

0 1000 2000 3000 4000 5000

uVolt

uVolt

uVolt

Time (msec)

0 1000 2000 3000 4000 5000


pre training


pre training














100 Nm

-2500

2500

3000

-3000

-4000

4000

position

Moment

EMG VL

EMG VM

EMG RF

Time (msec)

0 1000 2000 3000 4000 5000

uVolt

uVolt

uVolt

Time (msec)

0 1000 2000 3000 4000 5000


pre training


pre training














100 Nm

-2500

2500

3000

-3000

-4000

4000

position

Moment

EMG VL

EMG VM

EMG RF

Time (msec)

0 1000 2000 3000 4000 5000

uVolt

uVolt

uVolt

Time (msec)

0 1000 2000 3000 4000 5000


pre training


pre training

















100 Nm

-2500

2500

3000

-3000

-4000

4000

position

Moment

EMG VL

EMG VM

EMG RF

Time (msec)

0 1000 2000 3000 4000 5000

uVolt

uVolt

uVolt

Time (msec)

0 1000 2000 3000 4000 5000


pre training


pre training














100 Nm

-2500

2500

3000

-3000

-4000

4000

position

Moment

EMG VL

EMG VM

EMG RF

Time (msec)

0 1000 2000 3000 4000 5000

uVolt

uVolt

uVolt

Time (msec)

0 1000 2000 3000 4000 5000


pre training


pre training





Functional consequences

- enhanced acceleration

- elevated maximal movement velocity

- elevated muscle force & power during

rapid movements





21

Pro

cent

(%)

-15

-10

-5

0

5

10

15

20

S - %

E - %

SR - %

Pro

ce

nt (%

)

0

5

10

15

20

25

30

S - % d i f f

E - % d i f f

SR - % d i f f

Pre 5w 12w Pre 5w 12w

Max 10m walk speed Speed of Chair-rising x 5

*

* $

Changes in Functional Capacity

ST

SR

ES

ST

SR

ES

Suetta, Aagaard, Kjaer et al, JAGS 2004


Changes in mechanical muscle function and

functional capacity in response to resistance

training in elderly frail old women (75-88 yrs)

- After fall injury

Beyer et al, Clin Exp Res 2007

22

Females

70-90 yrs

Test

0 6 12

months

Test Test

Training

2 x1 h/w

Control

Test

Nina Beyer 2003

Muscle strength and functional performance

following strength training in elderly fall patients

Nina Beyer 2003



Maximal quadriceps and hamstring strength Isokinetic knee extension/flexion torque

Knee extension

60 deg/s

Knee flexion

60 deg/s

Months

0 3 6 9 12

To

rqu

e (

Nm

)

0

10

20

30

40

50

60

70

80

90***

**

*** *** ***

Mean ± SE. Change from baseline: **, ***

TG

CG

TG

CG

TG

CG

TG

CG


23

*** *** ***

Months

0 3 6 9 12

Wa

tts

0

50

60

70

80

90

100

******

***

TG

CG

Average

Mean ± SE. Change from baseline: ***

Maximal leg extension power Nottingham Power Rig


Chair rise time

Months

0 6 12

Chair

ris

e t

ime

(s)

0

7

8

9

10

11

12

13

14

C 0-12 mths, n=13

T 0-12 mths, n=14

Stair climbing time

Months

0 6 12

Sta

ir c

limbin

g (

s)

0

5

6

7

8

9

C 0-12 mths, n=13

T 0-12 mths, n=13

**

***

******

x 5

Mean ± SE, Change from baseline: **, ***

Functional motor performance rising from chair, stair climbing

TG

TG

CG

CG


Months

0 3 6 9 12

Sp

ee

d (

m/s

)

0.00

1.00

1.05

1.10

1.15

1.20

1.25

1.30

1.35

1.40

1.45

1.50

1.55

1.60

1.65

Months

0 3 6 9 12

******

***

******

***

Mean ± SE, Change from baseline: ***

Normal Maximal

Functional motor performance level walking: preferred speed and max speed

CG

CG

TG

TG


24

Walking speed 10 -15%

Stair climbing 20%

Chair rising 20%

Balance score 10 -15%

Maximal leg Power 35%

Knee strength 20 - 25%

Trunk strength 30 - 45%

Handgrip strength 7%

Daily activity

Functional ability

Muscle performance







- Effects of strength training

CONLUSIONS and SUMMARY

The age-related loss in muscle mass and the

concurrent decrease in maximal muscle strength,

rapid force capacity (RFD) and power can be

slowed or reversed by training (strength training!)

Likewise, the age-related impairment in neural function

can be effectively compensated by training (strength training)

!! ALSO the case in frail elderly patients !!

CONLUSIONs

25

SUMMARY Effects of strength training on

neuromuscular function and muscle size in the elderly

dynamic muscle strength, isometric muscle strength Frontera 1988, Fiatarone 1990, Häkkinen 1998, Harridge 1999, Suetta 2004, Beyer 2007

muscle power Beyer 2007, De Vos 2005, Caserotti 2008

Rapid force capacity (rate of force development: RFD) Häkkinen 1995 1998 2001, Hortobagyi 2001, Suetta 2004, Barry 2005, Caserotti 2008

Strength and Power

properties



Aagaard, Kjær et al, Scand J Med Sci Sports 2010




EMG amplitude and rate of EMG rise Häkkinen 1995 1998 2001, Suetta 2004, Barry 2005

maximal motor neuron firing frequency Kamen 1998, Patten 1999, Kamen & Knight 2004

improved force steadiness, enhanced fine motor control Hortobagyi 2001, Tracy 2004, Tracy & Enoka 2006

Neural factors

Strength and Power

properties

Aagaard, Kjær et al, Scand J Med Sci Sports 2010



26




EMG amplitude and rate of EMG rise Häkkinen 1995 1998 2001, Suetta 2004, Barry 2005

maximal motor neuron firing frequency Kamen 1998, Patten 1999, Kamen & Knight 2004

improved force steadiness, enhanced fine motor control Hortobagyi 2001, Tracy 2004, Tracy & Enoka 2006

single muscle fiber size (fiber CSA), whole muscle size (anatomical CSA)

Frontera 1988, Häkkinen 1998, Harridge 1999, Esmarck 2003, Kryger & Andersen 2007, Suetta 2004 2008

myogenic satellite cell activation MacKey 2007, Petrella 2008

muscle fiber pennation angle, tendon stiffness Reeves 2003, Reeves 2006, Suetta 2008

Muscular factors

Neural factors

Strength and Power

properties



Resistance Training

Adaptive changes in

muscle size and

neuromuscular

function

improved function

in ADL(activities of daily living)

THE OVERALL EFFECT OF STRENGTH TRAINING IN THE ELDERLY?

STRENGTH TRAINING

Acknowledgements

Coworkers at Institute of Sports Science and Clinical Biomechanics, University of

Southern Denmark; Institute of Sports Medicine Copenhagen, University of Copenhagen,

and Department of Physiotherapy, Institute of Neuroscience & Physiology, Sahlgrenska

Academy, Göteborg

Michael Kjær

Charlotte Suetta

Jesper L. Andersen

Peter Magnusson

Lena Hulthén

Christian Couppé

Paolo Caserotti

Lars Hvid

Cecilia Edwén

Ulrik Frandsen

Anders H Larsen

Nina Beyer

20 years 80 years - Fysioterapeuterna · Per Aagaard Institute of Sports Science and Clinical...

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