Aging.. the continuum of life

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1 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Loss in muscle mass and neuromuscular function with aging - Use of exercise as a countermeasure 2 years 8 years Per Aagaard Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark / paagaard@health.sdu.dk Department of Physiotherapy, Institute of Neuroscience & Physiology, Sahlgrenska Academy, University of Göteborg Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Aging.. the continuum of life Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 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 1

2 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Age-related changes in neuromuscular function Loss of muscle mass with aging: Sarcopenia Loss of muscle mass with aging: sarcopenia Reduced muscle cross-sectional area ( 4% between the age of 2 and 8 yrs) 31 yr (m) The decline seems to start in early adulthood and accelerate after the age of 5 years content of non-contractile tissue such as intramuscular fat and connective tissue Vandervoort, Muscle & Nerve 25, yr (m) 73 yr (f) 85 yr (f) Parise & Yarasheski, Curr Opin Clin Nutr Metab Care, 2 Paolo Caserotti, NIH Besthesda & IOB-SDU Loss of muscle mass with aging: sarcopenia Reduced Cross-sectional muscle cross-sectional images of area the QUADRICEPS muscle (MRI) ( 4% between the age of 2 and 8 yrs) "Sarcopenic obesity" The decline seems to start in early adulthood and accelerate after the age of 5 years content of non-contractile tissue such as intramuscular fat and connective tissue Vandervoort, 62-yr Muscle old & woman Nerve 25, yr old woman Parise & Yarasheski, Curr Opin Clin Nutr Metab Care, 2 31 yr (m) 66 yr (m) 73 yr (f) 85 yr (f) Caserotti, Aagaard et al 28 2

3 Reduction in muscle fiber size with aging Young subject Old subject courtesy C Suetta VL stainings courtesy JL Andersen CMRC 24 Sarcopenia (loss of muscle mass) Sarcopenia is significantly associated with 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 Photo courtesy Charlotte Suetta 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. 3

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 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 Korhonen et al, J Appl Physiol 26 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 4

5 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Age-related changes in neuromuscular function Loss of spinal motor neurons, CNS reorganization Neural factors - - neuromuscular function Neuromuscular changes related to aging spinal motor neurons, nerve axons, motor units units Brain Brain motor motor cortex cortex cerebellum cerebellum Spinal Spinal cord cord spinal spinal motor motor neurons neurons Muscle Muscle Total fiber number Motor unit number # Spinal motor neurons Reduced muscle mass, muscle CSA Spinal motor neurons reduced number of motor of motor neurons in the in the spinal spinal cord cord Muscle fiber size 25% 25% average loss loss of spinal of spinal motor motor Muscle strength neurons (lumbospinal segments L1-S3) L1-S3) from from 2 2 yrs yrs to 9 to 9 yrs yrs of age of age Motor Unit remodeling Tomlinson & Irving & Irving several subjects > 6 > 6 yrs yrs showing ~ 5% ~ 5% less less MN's MN's compared Motor to unit 2-4 to size 2-4 yrs yrs old old innervation ratio Tomlinson & Irving & Irving (# fibers/neuron) Vandervoort, Muscle & Nerve 25, 22 Neuromuscular changes related to aging spinal motor neurons Reduced muscle mass, muscle CSA # motor neurons = # motor units at increasing age motor axon Total fiber number Muscle fiber size ongoing process of Muscle denervation strength of skeletal muscle fibers late in life Motor Unit remodeling Vandervoort 22, McComas 1996 Motor Muscle unit number fibers # Spinal motor AJ McComas: Skeletal neurons muscle - form and function, 1996 Motor unit size innervation ratio (# fibers/neuron) Vandervoort, Muscle & Nerve 25, 22 5

6 Neuromuscular changes related to aging spinal motor neurons Reduced muscle mass, muscle CSA # motor neurons = # motor units at increasing age motor axon Total fiber number Muscle fiber size ongoing process of Muscle denervation strengthand reinnervation of skeletal muscle fibers late in life Motor Unit evidenced remodeling by - histological findings of fiber type grouping - elevated coexpression of MHC isoforms Motor - preferential atrophy of type II muscle fibers Muscle unit number Motor unit size fibers - very large MUAPs, indicating innervation ratio # Spinal motor innervation ratio AJ McComas: Skeletal neurons muscle (# fibers/neuron) Vandervoort 22, McComas form and function, 1996 Vandervoort, Muscle & Nerve 25, 22 SUMMARY - Muscular and Neuronal changes induced by Ageing Motor Unit remodeling Motor unit number # Spinal motor neurons Motor unit size innervation ratio (# fibers/neuron) Muscle strength Reduced muscle mass cross sectional area Total fiber number Muscle fiber size (pref. type II) Aagaard et al, Scand J Med Sci Sports 2, 21 SUMMARY - Muscular and Neuronal changes induced by Ageing Motor Unit remodeling Motor unit number # Spinal motor neurons Motor unit size innervation ratio (# fibers/neuron) Muscle strength Reduced muscle mass cross sectional area CONSEQUENCES FOR MECHANICAL MUSCLE PERFORMANCE? Total fiber number Muscle fiber size (pref. type II) Aagaard et al, Scand J Med Sci Sports 2, 21 6

7 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Age-related changes in neuromuscular function Impairments in mechanical muscle function Decreased Muscular Muscular Strength Strength With With Aging Aging Spirduso, Spirduso, Physical Physical dimensions dimensions of aging, of aging, Isometric Isometric muscle muscle strength strength Is preserved Is preserved to ~5-6 to ~5-6 yrs of yrs age of ag (cross (cross sectional sectional data) data) Decreases Decreases at a rate a rate of 1-1.5% of 1-1.5% per year per year from from 6-65th 6-65th year year Substantial Substantial individual individual differences difference! Vandervoort Vandervoort & McComas & McComas Spirdoso Spirdoso Maximal Muscle Power - elite master weightlifters trained untrained Peak Power Peak Power Mean Mean Power Power Pearson, Harridge et al; Med Sci Sports Exerc 22 7

8 Maximal Muscle Power - elite master weightlifters trained untrained Peak Power Peak Power 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) Mean Mean Power Power Pearson, Harridge et al; Med Sci Sports Exerc 22 Maximal Muscle Power - elite master weightlifters trained untrained Peak Power Peak Power 2 years 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) Mean Mean Power Power Pearson, Harridge et al; Med Sci Sports Exerc 22 Maximal SSC Muscle Power - Women vs Men? Maximal leg extensor muscle power assessed by force plate analysis Maximal counter-movement jumps: Stretch-Shortening Cycle muscle power Caserotti, Aagaard et al EJAP 21, Thorlund, Aagaard et al SJMSS 28, Edwén, Aagaard et al SJMSS 213 Cecilia Edwén et al SJMSS 213 8

9 Stair-climbing speed (m/s) Walking speed (m/s) Chair rising speed (s -1 ) 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 capacity Functional in the elderly performance is strongly influenced the elderly by maximal is influenced mechanical muscle power by maximal mechanical muscle power r=.83 r=.45 Women Men P<.5 P<.1 r=.86 r=.91 r=.93 r=.58 Leg extensor power (W/kg) Leg extensor power (W/kg) Bassey et al, 1992 Nursing Home residents 9

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 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? Brain motor cortex cerebellum Spinal cord Muscle 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? YES!... by means of strength / resistance training 1

11 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Age-related changes in neuromuscular function - Effects of strength training in old adults Adaptive alterations in muscle size, neuromuscular activity and mechanical muscle function Percentage increases in muscle CSA and Maximal muscle strength (MVC) with Strength Training in old vs young individuals Häkkinen 1985 Jones & Rutherford 1987 Narici 1996 Ferri 23 Frontera 1988 Häkkinen 1998 Harridge 1999 Narici et al: Training-induced changes in elderly muscl J. Musculoskel. Neron. Interact. 4, 24 Heavy-resistance strength training induces muscle fiber growth also in very old individuals (85-97 yrs, mean age 89 ± 3 yrs) 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 >7% 1 RM Kryger & Andersen, Scand J Med Sci Sports 27 11

12 Heavy-resistance strength training induces muscle fiber growth also in very old individuals ( 85 yrs) Mean age 89 ± 3 yrs (n=11), 3 sessions weekly, 12 wks Kryger & Andersen Scand J Med Sci Sports 27 Heavy-resistance strength training induces muscle fiber growth also in very old individuals (85-97 yrs, mean age 89 ± 3 yrs) 85 year old discharged geriatric patients 12 weeks of resistance exercise knee ext. 3 x weekly, 3 x 8 rep, >7% 1 RM Kryger & Andersen, Scand J Med Sci Sports 27 Results Type IIa fibre CSA 22% Quadriceps strength 4-45% Chair rising time (5 reps) 3% faster Maximal walking speed 25% faster p <.5 Increases in muscle fibre size in older individuals following high-intensity dynamic leg strength training. Based on biopsy samples obtained from vastus lateralis Study Frontera et al., J. Appl. Physiol. 64, 1988 Charette et al., J. Appl. Physiol. 7, 1991 Grimby et al., J. Appl. Physiol. 73, 1992 Häkkinen et al. J. Gerontol. 53B, 1998 Fiatarone-Singh et al. Am. J. Physiol. 277, 1999 Hunter et al., J. Appl. Physiol. 86, 1999 Hikida et al. J. Gerontol. 55, 2 Vandervoort, Muscle & Nerve 25, 22 Type I Muscle fiber size increase (%) Type II < > <

13 Force m. quadriceps femoris Force Force Force (N) Force (N) Contractile Rate of Force Development (RFD) Rapid Maximal Force Explosive Capacity (Explosive Muscle muscle Strength strength) Maximal Rate of Explosive Force Development Muscle Strength (RFD) Rate of Force Development (RFD) RFD = RFD = Force / Time Force / Time max Force max Force Time Time Time (seconds) Time (seconds) Aagaard et al, J Appl Physiol 22 RFD Contractile Rate Rate of Force of Force Development Development Maximal explosive Rapid force muscle capacity strength (RFD) in in elderly vs vs young individuals Force (N) RFD = Force / Time Time Time (seconds) Contractile RFD is substantially reduced in healthy aging individuals compared to young individuals max Force RFD (Nm/s/kg) ms 5 ms -3 ms 5 ms -3-3 ms ms 5 5 ms ms Clarckson et al 1981, Häkkinen et al 1995, Clarckson et al. 1981, Häkkinen et al. 1995, Izquierdo et al. 1999, Korhonen Izquierdo et al. 26, et al 1999, Barry et al. 25, Klass et al 28, Suetta, Hvid Korhonen et al 28 et al 26, Klass et al 28, Suetta, Kjær, Aagaard et al 29 Young (67 yr, n=9) Old (24 yr, n=11) Young (24 yr, n=9) Old (67 yr, n=11) Y < O (p<.5) Suetta, Kjær, Aagaard et al, J Appl Physiol 29 What is the effect of strength training on maximal contractile rate of force development (RFD) in elderly individuals? 13

14 Explosive-type resistance training in the old (6 yrs) and the very old (8 yrs) Subjects Mean age 62.7 (SD 2.2) and 81.8 (SD 2.7) yrs n = con n = con Caserotti, Aagaard et al, SJMSS 28 Explosive-type resistance training in the old (6 yrs) and the very old (8 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 (5% 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 75-8% 1RM loads, 8-1 reps, 4 sets each exercise Caserotti, Aagaard et al, SJMSS 28 Explosive-type resistance training in the old and the very old Static leg extensor MVC Unilateral isometric leg press test device Paolo Caserotti 14

15 Newton Explosive-type resistance training in the old and the very old F peak 12 F5 1 8 F3 6 F1 F5 4 Start of contraction 2 Force Time (msec) 6 Paolo Caserotti Explosive-type resistance training in the old and the very old marked increases in rapid force capacity (RFD) Contractile Rate of Force Development Leg Press MVC; -2 ms 6 yrs old 8 yrs old week (pre) 12 weeks (post) +18% +51% TG6 TG6 CG6 CG6 TG8 TG8 TG6 CG8 CG8 CG6 TG8 CG8 P<.5 within-group changes (n=2) (n=2) (n=12) (n=13) Caserotti, Aagaard et al, Scand J Med Sci Sports Exerc 28 Explosive-type resistance training in the old and the very old marked increases in rapid force capacity (RFD) Contractile Rate of Force Development Leg Press MVC; -2 ms 6 yrs old Diff = 43% p <.1 8 yrs old week (pre) 12 weeks (post) TG6 TG6 CG6 CG6 TG8 TG8 TG6 CG8 CG8 CG6 TG8 CG8 P<.5 within-group changes (n=2) (n=2) (n=12) (n=13) Caserotti, Aagaard et al, Scand J Med Sci Sports Exerc 28 15

16 Explosive-type resistance training in the old and the very old marked increases in rapid force capacity (RFD) Contractile Rate of Force Development Leg Press MVC; -2 ms 6 yrs old Diff = 43% p <.1 8 yrs old week (pre) 12 weeks (post) Diff = 15% n.s. TG6 TG6 CG6 CG6 TG8 TG8 TG6 CG8 CG8 CG6 TG8 CG8 P<.5 within-group changes (n=2) (n=2) (n=12) (n=13) Caserotti, Aagaard et al, Scand J Med Sci Sports Exerc 28 Explosive-type resistance training in the old and the very old marked increases in rapid force capacity (RFD) Contractile Rate of Force Development Leg Press MVC; -2 ms 6 yrs old Diff = 43% p <.1 8 yrs old week (pre) 12 weeks (post) Diff = 15% n.s. 12 wks of explosive-type HRST in 8 yr old TG6 (n=2) 2 years TG6 younger! CG6 (n=2) CG6 TG8 TG8 TG6 CG8 CG8 CG6 TG8 (n=12) CG8 (n=13) P<.5 within-group changes Caserotti, Aagaard et al, Scand J Med Sci Sports Exerc 28 Explosive-type resistance training in the old and the very old marked increases in rapid force capacity (RFD) TG 6 TG8 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<.5) Caserotti, Aagaard et al, Scand J Med Sci Sports Exerc 28 16

17 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Age-related changes in neuromuscular function - 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? 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... Strength training is the only exercise modality known to effectively increase muscle mass Effects of strength training in elderly patients Well, does the need exist? Quadriceps muscle CSA Significant muscle atrophy may be observed in response to acute short-term disuse (4-14 days immobilization) (24 yrs) (67 yrs)... recovery is more difficult to achieve in old individuals! Hvid, Aagaard, Suetta et al, J Appl Physiol 29 17

18 Effects of strength training in elderly patients Well, does the need exist? Young Old (24 yrs) (67 yrs) 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 213 Effects of resistance training rehabilitation on muscle mass and functional capacity in elderly hip replacement patients Suetta, Aagaard et al, J Appl Physiol 24 Rehabilitation of muscle mass and neuromuscular function following Hip Replacement Surgery in old adults (6-86 yrs) by use of resistance training 6 yrs S U R G E R Y Standard Rehabilitation (n=8) - SR + unilateral Strength Training (n=1) - ST + unilateral Electrical Stimulation (n=1) - ES Wks MVC MVC Biopsy UL-scan MVC Biopsy UL-scan MVC Biopsy UL-scan Suetta, Aagaard, Kjaer et al, J Appl Physiol 24 18

19 CSA (mm²) Rehabilitation from elective Hip replacement Surgery by use of Strength Training Strength Training protocol Strength exercises - heavy loads unilateral heavy-resistance strength training - Affected Limb Kneeextension Legpress Wks 1-2: 3x1 (2 RM), Wks 3-4: 3x12 (15 RM), Wks 5-6: 4x1 (12 RM) Wks 7-8: 5x8 (8 RM), Wks 9-1: 4x8 (8 RM), Wks 11-12: 3x8 (8 RM) Suetta, Aagaard et al, J Appl Physiol 24 Rehabilitation from elective Hip replacement Surgery by use of Strength Training Changes in anatomical Muscle Cross Sectional Area (CT-scanning) Standard Rehab SR Electro Stimulation ES Strength Training ST # CSA (%) S ST - CSA % E ES - CSA % K SR - CSA % ST ES SR 3 Pre 5wk 12wk Pre 5wk 12wk Pre 5wk 12wk 92 9 # Pre 5w 12w Suetta, Aagaard et al, J Appl Physiol 24 Rehabilitation from elective Hip replacement Surgery by use of Strength Training Changes in maximal muscle strength (isometric MVC) Isometric strength RT ES SR resistance electrical standard training stimulation rehabilitation +24% strength-op elstim-op kontrol-op Torque (Nm) # -22% 4 2 Pre 5w 12w Pre 5w 12w Pre 5w 12w Suetta et al, J Appl Physiol wk > pre (p<.5); # 5 wk < pre,12 wk (p<.5) 19

20 Rehabilitation from elective Hip replacement Surgery by use of Strength Training Changes in neuromuscular activity (muscle EMG) and Rapid Force Capacity (RFD) Rehabilitation from elective Hip replacement Surgery by use of Strength Training Changes in neuromuscular activity (muscle EMG) Training induced changes changes in and Rapid Force Capacity in (RFD) explosive explosive muscle muscle strength strength (RFD) Training induced changes (RFD) in Adaptive responses in aged individuals Adaptive explosive responses muscle in aged strength individuals (RFD) Adaptive responses in aged individuals Heavy-resistance strength training Heavy-resistance strength training Heavy-resistance strength training Concurrent increases in Concurrent Concurrent increases in maximal RFD and neuromuscular activity (iemg) maximal maximal RFD RFD and and neuromuscular activity in elderly individuals (iemg) (iemg) in elderly individuals in elderly individuals Häkkinen Häkkinen & Häkkinen & Häkkinen (age (age 5, 7 yrs, gender F, F, M) M) Häkkinen Häkkinen et & al. Häkkinen et 1998 al (age 1995 (age 4, 4, (age 6 6 yrs, 5, gender 7 yrs, F, F, M) gender M) F, M) Häkkinen Häkkinen et et al. et al. 21 al (age (age (age , yrs, yrs, 6 gender F) yrs, gender F, M) Suetta et al. 24 (post hip replacement surgery, 6-86 yrs) Suetta Häkkinen et al. et 24 al. 21 (post(age hip replacement 63 yrs, gender surgery, F) 6-86 yrs) Barry et al. 25 (age 6-79 yrs, gender F, M) Barry Suetta et et al. al (age (post 6-79 hip yrs, replacement gender F, M) surgery, 6-86 yrs) Barry et al. 25 (age 6-79 yrs, gender F, M) Rehabilitation from elective Hip replacement Surgery by use of Strength Training Changes in neuromuscular activity (muscle EMG) Training induced induced changes changes in in in and Rapid Force Capacity (RFD) explosive muscle strength (RFD) (RFD) Training induced changes in Adaptive in Adaptive explosive responses responses muscle in in aged aged strength individuals individuals (RFD) Adaptive responses in aged individuals Heavy-resistance strength strength training training Heavy-resistance strength training Concurrent increases in Concurrent Concurrent increases increases in in maximal RFD and neuromuscular activity (iemg) maximal maximal RFD RFD and and neuromuscular in elderly individuals activity (iemg) (iemg) in in elderly individuals Häkkinen Häkkinen & Häkkinen & Häkkinen (age (age 5, 7 yrs, gender F, F, M) M) Häkkinen Häkkinen et & al. Häkkinen et 1998 al (age 1995 (age 4, 4, (age 6 6 yrs, 5, gender 7 yrs, F, F, M) gender M) Functional consequences F, M) Häkkinen Häkkinen et et al. et al. 21 al (age (age (age , yrs, yrs, 6 gender F) yrs, gender F, M) Suetta et al. 24 (post hip replacement surgery, 6-86 yrs) - enhanced Suetta Häkkinen et al. et acceleration 24 al. 21 (post(age hip replacement 63 yrs, gender surgery, F) 6-86 yrs) Barry et al. 25 (age 6-79 yrs, gender F, M) Barry Suetta et et al. al (age (post 6-79 hip yrs, replacement gender F, M) - elevated maximal movement velocity surgery, 6-86 yrs) Barry et al. 25 (age 6-79 yrs, gender F, M) - elevated muscle force & power during rapid movements 2

21 Rehabilitation from elective Hip replacement Surgery by use of Strength Training Changes in Functional Capacity Max 1m walk speed Speed of Chair-rising x 5 Procent (%) S - % E - % SR - % ST ES SR Procent (%) S - % d i f f E - % d i f f SR - % d i f f ST ES SR $ Pre 5w 12w Pre 5w 12w Suetta, Aagaard, Kjaer et al, JAGS 24 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 27 21

22 Muscle strength and functional performance following strength training in elderly fall patients Females 7-9 yrs Test Training 2 x1 h/w Control 6 12 Test Test Test months Nina Beyer 23 Muscle strength and functional performance following strength training in elderly fall patients Nina Beyer 23 Maximal quadriceps and hamstring strength Isokinetic knee extension/flexion torque Torque (Nm) TG TG CG CG TG TG CG CG Knee extension 6 deg/s Knee flexion 6 deg/s Months Mean ± SE. Change from baseline:, Beyer et al, Clin Exp Res 27 22

23 Maximal leg extension power Nottingham Power Rig Average 1 9 TG Watts 8 7 CG Months Mean ± SE. Change from baseline: Beyer et al, Clin Exp Res 27 Functional motor performance rising from chair, stair climbing 14 Chair rise time 9 Stair climbing time Chair rise time (s) CG TG Stair climbing (s) CG TG 8 7 x Months C -12 mths, n=13 T -12 mths, n=14 Months C -12 mths, n=13 T -12 mths, n=13 Mean ± SE, Change from baseline:, Beyer et al, Clin Exp Res 27 Functional motor performance level walking: preferred speed and max speed Speed (m/s) Normal TG CG Months Maximal TG CG Months Mean ± SE, Change from baseline: Beyer et al, Clin Exp Res 27 23

24 Muscle strength and functional performance following strength training in elderly fall patients Daily activity Walking speed 1-15% Stair climbing 2% Chair rising 2% Functional ability Balance score 1-15% Maximal leg Power 35% Muscle performance Knee strength 2-25% Trunk strength 3-45% Handgrip strength 7% Beyer et al, Clin Exp Res 27 Träning för äldre Utbildningsdag Sjukgymnastdagarna, Göteborg October 4th, 213 Age-related changes in neuromuscular function - Effects of strength training CONLUSIONS and SUMMARY CONLUSIONs 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!! 24

25 SUMMARY Effects of strength training on neuromuscular function and muscle size in the elderly SUMMARY Effects of strength training on neuromuscular function and muscle size in the elderly Strength and Power properties dynamic muscle strength, isometric muscle strength Frontera 1988, Fiatarone 199, Häkkinen 1998, Harridge 1999, Suetta 24, Beyer 27 muscle power Beyer 27, De Vos 25, Caserotti 28 Rapid force capacity (rate of force development: RFD) Häkkinen , Hortobagyi 21, Suetta 24, Barry 25, Caserotti 28 Aagaard, Kjær et al, Scand J Med Sci Sports 21 SUMMARY Effects of strength training on neuromuscular function and muscle size in the elderly Strength and Power properties dynamic muscle strength, isometric muscle strength Frontera 1988, Fiatarone 199, Häkkinen 1998, Harridge 1999, Suetta 24, Beyer 27 muscle power Beyer 27, De Vos 25, Caserotti 28 Rapid force capacity (rate of force development: RFD) Häkkinen , Hortobagyi 21, Suetta 24, Barry 25, Caserotti 28 Neural factors EMG amplitude and rate of EMG rise Häkkinen , Suetta 24, Barry 25 maximal motor neuron firing frequency Kamen 1998, Patten 1999, Kamen & Knight 24 improved force steadiness, enhanced fine motor control Hortobagyi 21, Tracy 24, Tracy & Enoka 26 Aagaard, Kjær et al, Scand J Med Sci Sports 21 25

26 SUMMARY Effects of strength training on neuromuscular function and muscle size in the elderly Strength and Power properties dynamic muscle strength, isometric muscle strength Frontera 1988, Fiatarone 199, Häkkinen 1998, Harridge 1999, Suetta 24, Beyer 27 muscle power Beyer 27, De Vos 25, Caserotti 28 Rapid force capacity (rate of force development: RFD) Häkkinen , Hortobagyi 21, Suetta 24, Barry 25, Caserotti 28 Neural factors EMG amplitude and rate of EMG rise Häkkinen , Suetta 24, Barry 25 maximal motor neuron firing frequency Kamen 1998, Patten 1999, Kamen & Knight 24 improved force steadiness, enhanced fine motor control Hortobagyi 21, Tracy 24, Tracy & Enoka 26 Muscular factors single muscle fiber size (fiber CSA), whole muscle size (anatomical CSA) Frontera 1988, Häkkinen 1998, Harridge 1999, Esmarck 23, Kryger & Andersen 27, Suetta myogenic satellite cell activation MacKey 27, Petrella 28 muscle fiber pennation angle, tendon stiffness Reeves 23, Reeves 26, Suetta 28 THE OVERALL EFFECT OF STRENGTH TRAINING IN THE ELDERLY? STRENGTH TRAINING Resistance Training Adaptive changes in muscle size and neuromuscular function improved function in ADL (activities of daily living) 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 Paolo Caserotti Lars Hvid Cecilia Edwén Ulrik Frandsen Anders H Larsen Nina Beyer Michael Kjær Charlotte Suetta Jesper L. Andersen Peter Magnusson Lena Hulthén Christian Couppé 26