Newsgroup: it.salute.alimentazione
Titolo: Proteine, massa muscolare e performance fisica

(Journal of Nutrition. 2000;130:886-889.)
© 2000 The American Society for Nutritional Sciences
Article
Metabolic Consequences of a High Dietary-Protein Intake in Adulthood:
Assessment of the Available Evidence
Cornelia C. Metges1 and Christian A. Barth 
[...]
Protein intake, lean body mass and physical performance
 
One of the main questions is whether chronic intake of high-protein diets
may be of any value in promoting increased lean body mass (Garlick et al.
1999 ). The answer to this question is important not only for athletes and
body builders who tend to believe that a high-protein intake is crucial for
their physical performance (Linseisen et al. 1993 ) but for all those
conditions characterized by a decreasing lean body mass, as seen in the
elderly (Nair 1995 ) and various catabolic situations.
An increase of daily protein intake from 1.35 to 2.62 g · kg-1 for 1 mon in
the habitual diet (170 kJ · kg-1 · d-1) while performing daily weight
training did not affect either strength or muscle mass (Lemon et al. 1992
). Also the response of protein turnover to exercise (4 h at 40% VO2 max.)
was independent of dietary protein intake (0.9 or 2.5 g · kg-1 · d-1) from
isoenergetic diets (Carraro et al. 1990 ). High-protein meals did not
enhance the stimulation of myofibrillar synthesis induced by resistance
exercise in muscle of elderly men and women (Welle and Thornton 1998 ).
Daily physical exercise of increasing intensity at neutral energy balance
(constant protein intake 0.57 g · kg-1 · d-1) maintained body protein by an
improvement of N utilization (Butterfield and Calloway 1984 ). This
suggests that physical activity has a positive effect on N retention even
at a low level of protein intake, provided energy balance is achieved.
Millward et al. (1994) stated that, "training and energy intake depress
protein needs and habitual protein intake elevates protein needs." In
conclusion, the literature provides no evidence that protein nutriture and
physical performance are improved by high-protein diets, the more so as
Garlick et al. (1999) considered that there are currently no methods
sensitive enough to detect whether high-protein intake results in a
long-term increase in functional lean tissue.
[...]
http://www.nutrition.org/cgi/content/full/130/4/886?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=kidney+high-protein&searchid=1119660946899_6054&stored_search=&FIRSTINDEX=0&sortspec=relevance&journalcode=nutrition#B5

 long-term increase in functional lean tissue.
tuttavia questa frase rende chiaro il concetto che la medicina non č in
grado di
quantificare e prevedere tutto e, in molti casi, contano l'esperienza
personale
e l'intuito di qualcuno.
Personalmente con un incremento da poco piů di 1g a circa 1,5g di effetti ne
ho visti ...
Ciao
Gianni

Flakoll PJ, et al. Postexercise protein supplementation improves health and
muscle soreness during basic military training in marine recruits. Journal
of Applied Physiology, 2004; 96: 951-956.
http://jap.physiology.org/cgi/content/full/96/3/951
Healthy male US Marine recruits undergoing 54 days of basic training were
randomly assigned to one of three treatments immediately post-exercise:
1) placebo (0 g carbohydrate, 0 g protein, 0 g fat),
2) control (8, 0, 3), or protein supplement (8, 10, 3).
..............
The researchers concluded: "Postexercise protein supplementation may not
only enhance muscle protein deposition but it also has significant potential
to positively impact health, muscle soreness, and tissue hydration during
prolonged intense exercise training, suggesting a potential therapeutic
approach for the prevention of health problems in severely stressed
exercising populations."
Basic training for US Marine Corps recruits is mentally, emotionally, and
physically very stressful. Catabolism due to the demanding regimen has been
hypothesized to cause losses in lean body mass, to compromise health, and to
reduce immune function. Such a contention was well-supported by this study;
the recruits experienced significant losses of total body mass, lean body
mass, cell mass, and body water over the 54-day period. Furthermore, there
was an average of 1.6 medical visits per recruit over the training period.
However, compared with the placebo and control groups, the
protein-supplemented group had an average of 33% fewer total medical visits,
28% fewer visits due to bacterial/viral infections, 37% fewer visits due to
muscle/joint problems, and 83% fewer visits due to heat exhaustion. Muscle
soreness immediately post-exercise was also reduced by protein
supplementation when compared to the placebo and control treatments
Ciao!
Gianni

 ho visti ...
Ah, ora capisco quell'accaloramento sulle proteine... un altro palestrato.. 

 Ah, ora capisco quell'accaloramento sulle proteine... un altro
palestrato..
Sbagliato in pieno: ho 45 anni e non vado in palestra da più di 10 anni.
Però mi mantengo in forma sia fisica che mentale, al contrario di
taluni che sentenziano di cose di cui non sanno assolutamente nulla.
Sabato ho fatto Palermo-Trapani in bici, con relativo ritorno ieri.
Ciao
Gianni

 Sabato ho fatto Palermo-Trapani in bici, con relativo ritorno ieri.
..e ? 

 un altro palestrato
che di lavoro mi occupo di ricerca scientifica ed insegnamento
universitario
In definitiva, se fai affermazioni, falle con cognizione e facendo dei
riferimenti, viceversa scrivi "secondo me...", "il mio parere è..."
così si capisce che sono opinioni di uno che ne sa poco ed evitiamo di
perderci tempo.
E renditi bene conto che le affermazioni di un palestrato documentato
valgono più di uno "che ne sa poco" 
Ciao
Gianni

Non mi pare di avere indicato espressamente qualcuno.
Ma vai a prendere per il culo qualcun'altro va.