PROTEIN DURING WEIGHT LOSS TO MAINTAIN MUSCLE
1
Hector AJ1, Phillips SM1.
SUMMARY
– Current recommendations for protein intakes during weight loss in athletes are set at 1.6-2.4 g protein/kg/day
– Severity of caloric deficit and training type and intensity determines at what end of this range athletes choose to be
Longland TM1, Oikawa SY1, Mitchell CJ1, Devries MC1, Phillips SM2
DESIGN
– 4 wks
– Hypoenergetic (~40% reduction compared with requirements) diets providing 33 kcal/kg LBM
– Young men (2 groups; n = 20/group)
(a) lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON)
(b) higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO)
– All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk
RESULTS
– LBM increased in the PRO group to a greater extent compared with the CON group
– PRO group had a greater loss of fat mass than did the CON group
CONSIDERATIONS FOR PROTEIN INTAKE IN MANAGING WEIGHT LOSS IN ATHLETES – 2015
Murphy CH1, Hector AJ, Phillips SM.
(1) Higher protein intakes during periods of energy restriction can enhance fat-free mass (FFM) preservation, particularly when combined with exercise
(2) From a practical point of view, athletes aiming to reduce fat mass and preserve FFM should be advised to consume protein intakes in the range of;
– approx. 1.8-2.7 g/kg/day or approx. 2.3-3.1 g/kg FFM/day in combination with a moderate energy deficit (-500 kcal) and some form of resistance exercise
– Note: 80kg (176lbs) x 1.8 = 144g PRO; 80kg (176lbs) x 2.7 = 216g PRO
THE EFFECTS OF WHEY PROTEIN WITH OR WITHOUT CARBS ON RESISTANCE TRAINING ADAPTATIONS – 2015
Hulmi JJ1, Laakso M1, Mero AA1, Häkkinen K1, Ahtiainen JP1, Peltonen H1.
METHODS
– 4-wk prep RT period was conducted in untrained males to standardize training background of the subjects
– Thereafter, the subjects were randomized into 3groups:
A) 30 g of whey proteins (n = 22)
B) isocaloric carbohydrates (maltodextrin, n = 21)
C) protein + carbohydrates (n = 25)
– Within groups, subjects were put into two whole-body 12-wk RT regimens for muscle hypertrophy and maximal strength or muscle strength, hypertrophy and power
– The post-exercise drink was taken immediately after the exercise bout, 2-3x/wk depending on the training period
RESULTS
– 12-week RT led to increased fat-free mass, muscle size and strength independent of post-exercise nutrient intake
– The whey PRO group reduced more total and abdominal area fat compared to carb group independent of type of RT
– A larger relative increase (per kg bodywt) in fat-free mass was observed in the PRO vs. Carb group without significant differences to the combined group
A REVIEW OF DIETARY PROTEIN DURING CALORIC RESTRICTION IN RESISTANCE TRAINED LEAN ATHLETES – 2014
Helms ER1, Zinn C, Rowlands DS, Brown SR.
– PRO needs for energy-restricted resistance-trained athletes are likely 2.3-3.1g/kg of FFM (Fat Free Mass) scaled upwards with severity of caloric restriction and leanness
My Examples:
(1) 80kg or 176lb person at 10% bodyfat = 72kg or 158lbs FFM (Fat-Free Mass)
Therefore, 72kg x 2.3g = 165g Protein and 72kg x 3.1g = 223g Protein; Protein range for that person would be 165 to 223g
(2) 80kg or 176lb person at 15% bodyfat = 68kg or 150lbs FFM (Fat-Free Mass)
Therefore, 68kg x 2.3g = 156g Protein and 68kg x 3.1g = 211g Protein; Protein range for that person would be 156 to 221g
REDUCED MPS IS RESCUED BY RESISTANCE EXERCISE AND PROTEIN FOLLOWING SHORT-TERM ENERGY DEFICIT – 2014
Areta JL1, Burke LM, Camera DM, West DW, Crawshay S, Moore DR, Stellingwerff T, Phillips SM, Hawley JA, Coffey VG.
AIM
– Myofibrillar protein synthesis (MPS) response to resistance exercise (REX) and PRO during energy deficit (ED)
METHOD
– Young men (n=8) and women (n=7),
(1) Resting post-absorptive MPS during energy balance – EB
(2) After 5 days of Energy Deficit – ED
(3) MPS while in ED after acute REX in the fasted state and with the ingestion of whey protein (15 and 30 g)
RESULTS
(1) Post-absorptive rates of MPS were 27% lower in ED than EB
(2) but REX stimulated MPS to rates equal to EB
(3) Ingestion of 15 and 30 g of protein after REX in ED increased MPS ~16 and ~34% above resting EB
