1 Dairy protein and muscle Dairy protein and muscle strength; strength; Implications for fall prevention. Implications for fall prevention. Dr David Cameron Dr David Cameron-Smith Smith Senior Lecturer Senior Lecturer School of Exercise and Nutrition Sciences School of Exercise and Nutrition Sciences Deakin University Deakin University 2 3 4 Influence of age on muscle mass Influence of age on muscle mass 0 10 20 30 40 50 15 25 35 45 55 65 75 85 Age (years) Muscle Mass (kg) Men Women 25 year old man 65 year old man Janssen et al., J Appl Physiol 89:81-88, 2000 5 Longitudinal changes in muscle mass Longitudinal changes in muscle mass 20 25 30 35 40 45 50 55 60 65 1982 1990 Quadriceps CSA (cm 2 ) C.A. Grieg et al., Muscle & Nerve 1993;16:6-10 (x = 74 yr) (x = 82 yr) 6 Association between severe Association between severe sarcopenia sarcopenia and physical function in older women and physical function in older women 0 1 2 3 4 5 6 7 8 9 10 11 Performing Chores Preparing Meals Personal Care Needs 5 Chair Stands Walk 8 Feet Lift 10 lbs Climb 10 Stairs Walk 1/4 Mile Adjusted Odds Ratio (95% CI) (Normal Muscle used as Referent Group) Janssen et al., J Am Geriatr Soc 50:889-896, 2002
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Dairy protein and muscle Dairy protein and muscle strength; strength;
Implications for fall prevention.Implications for fall prevention.
Dr David CameronDr David Cameron--SmithSmith
Senior LecturerSenior LecturerSchool of Exercise and Nutrition SciencesSchool of Exercise and Nutrition Sciences
Deakin UniversityDeakin University
22
33 44
Influence of age on muscle massInfluence of age on muscle mass
0
10
20
30
40
50
15 25 35 45 55 65 75 85
Age (years)
Mus
cle
Mas
s (k
g)
Men Women25 year old man
65 year old man
Janssen et al., J Appl Physiol 89:81-88, 2000
55
Longitudinal changes in muscle massLongitudinal changes in muscle mass
20253035404550556065
1982 1990
Qua
dric
eps
CSA
(cm
2 )
C.A. Grieg et al., Muscle & Nerve 1993;16:6-10
(x = 74 yr) (x = 82 yr)
66
Association between severe Association between severe sarcopeniasarcopeniaand physical function in older womenand physical function in older women
0 1 2 3 4 5 6 7 8 9 10 11
Performing Chores
Preparing Meals
Personal Care Needs
5 Chair Stands
Walk 8 Feet
Lift 10 lbs
Climb 10 Stairs
Walk 1/4 Mile
Adjusted Odds Ratio (95% CI)(Normal Muscle used as Referent Group)
Janssen et al., J Am Geriatr Soc 50:889-896, 2002
77
Vicious Cycle of Vicious Cycle of SarcopeniaSarcopenia
88
No loss of fibre strength with ageNo loss of fibre strength with age
00.20.40.60.8
11.2
Type 1 Type 2
YMYW
OMOW
Trappe S et al J. Physiol. 552: 47-58, 2003.
*
*
99
Muscle plasticityMuscle plasticity
1010
Skeletal MuscleSkeletal Muscle
1111
Multinucleated Multinucleated myofibresmyofibres
Newlands S. et al. Genes & Development 12: 2748-2758, 1998 1212
Hawke & Garry J App Physiol. 91: 534-551, 2001.
1313
Muscle recovery following Muscle recovery following cardiotoxincardiotoxinexposureexposure
Garry DJ et al PNAS 97: 5416-21, 20001414
Zoico et al (2002). Nutrition Reviews 60: 39-51
1515
The Interplay Between Chronic The Interplay Between Chronic Inflammation & Acute Phase ResponseInflammation & Acute Phase Response
As yet there is no As yet there is no data that data that demonstrates demonstrates whether whether supplemental supplemental protein ingestion, protein ingestion, following following eccentric exercise eccentric exercise is able to is able to favourably impact favourably impact on the chronic and on the chronic and acuteacute--phase phase 1616
*
#
^
* denotes a significant difference (P<0.05) in the Placebo group between the pre and 2hr time point. ̂denotes a significant difference (P<0.05) between the Placebo and BLG group at the 2hr time point.
# denotes a significant difference (P<0.05) in the BLG group between the pre and 2hr time potnt.
Older males Older males –– Impact of TimingImpact of Timing
Immediate
2hours after
Esmark et al. J. Physiol. 535: 301-311, 2001 4040
Changes in Muscle CharacteristicsChanges in Muscle Characteristics
Esmark et al. J. Physiol. 535: 301-311, 2001
4141
In young males?In young males?
Burke et al. Int. J. Sport Nutr. Exerc. Metab. 11: 349-64, 2001 4242
In bodybuilders…In bodybuilders…The effect of VP2 whey isolate, The effect of VP2 whey isolate, micronizedmicronized creatine and resistance creatine and resistance
training on fibre characteristics, strength and body compositiontraining on fibre characteristics, strength and body composition11 week intervention in resistance-trained men.