Whey protein studies in the news

How much whey protein is needed after exercise to boost muscle building

Only one study has determined the dose response effect of protein provided after resistance exercise. Using egg protein, the study showed that muscle protein synthesis reached a plateau when 20 grams of protein was ingested. When 40 grams was ingested, there was no further increase in muscle protein synthesis. A similar study was recently conducted with whey protein isolate. Subjects consumed whey after a bout of single leg knee extensions, using the non-exercised leg as a control. The subjects were older, with an average age of 70 years.

After exercising one leg, they consumed a drink containing 0, 10, 20 or 40 grams of whey protein isolate. Measures of muscle protein synthesis were determined for 4 hours after exercise in the control (non-exercised) leg (to assess the effects of simply ingesting whey without exercise), and in the exercised leg (to assess the effects of whey plus resistance exercise). Rates of muscle protein synthesis were higher in the exercised leg compared to the control leg at all doses of whey, consistent with the synergistic effect of whey and exercise.

In the control (non-exercised) leg, there was a significant increase in muscle protein synthesis with the 20 gram dose, but no further increase with 40 grams. In the exercised leg, there was a significant increase in muscle protein synthesis with 20 grams of whey, and a further 32% increase with the 40 gram dose. This indicates that 20 grams of whey was necessary to significantly increase muscle protein synthesis at rest in elderly subjects, but after resistance exercise, a higher dose may be needed to achieve a maximal increase in muscle protein synthesis.


Do older adults really need more protein?

When you ingest protein, the amino acids that are digested and absorbed into the bloodstream trigger a response in muscle to convert amino acids into protein. This anabolic response to the ingestion of protein is one of the main reasons whey and other protein supplements are popular as post-exercise supplements. However, research has shown that as you age you tend to become resistant to this positive effect of protein ingestion. The good news is that research indicates that this ‘anabolic resistance’ can be overcome by ingesting greater amounts of protein, especially leucine.

For example, in one recent study, elderly individuals had a 69% greater increase in muscle protein synthesis after exercise when they consumed 20 grams of whey (2.6 grams of leucine) compared to 20 grams of casein (1.6 grams of leucine). In an older group of active 70-year-olds, it was shown that 40 grams of whey consumed after resistance exercise produced a 32% greater increase in muscle protein synthesis compared to a 20-gram dose of whey. In contrast, 20 grams of protein appears to be enough to maximize muscle protein synthesis in younger individuals.

Recent results from training studies have demonstrated that greater amounts of protein are needed to overcome the blunted response to protein older adults experience. In one of these experiments, 80 adults 70 to 85 years of age participated in a resistance training program (3 days per week) for 6 months. One group was randomized to receive whey protein (20 grams two times per day) while another group received carbohydrate as a control. The whey group had greater increases in lean body mass (1.3 vs 0.7 pounds) than the carbohydrate group. This was confirmed by greater muscle mass in the thigh from computed tomography (4.6 vs 2.9%).

In summary, older adults need a higher protein dose than younger people. Older adults should consume at least 20-40 grams of whey after exercise to achieve a maximal increase in muscle protein synthesis. 


Double your weight loss when extra whey protein is added to a diet program

When you restrict calorie intake, which is a common approach when dieting, it can result in the loss of both fat and lean muscle tissue. However, you want to preserve as much muscle tissue as possible during weight loss to maintain strength and performance. Supplementing with whey protein during dieting may be an effective way to preserve lean tissue. Whey has a high content of leucine and it provides anabolic effects on muscle protein synthesis.

Researchers at the University of Illinois had overweight women participate in a 6-month weight loss program. The women were given diet plans that included protein intake at the recommended dietary allowance of 0.8g per kilogram of body weight (about 55g of protein for a 150-pound woman). One group of women received an additional 25g of whey protein two times per day, while the second group received the same amount of a carbohydrate supplement. Both groups consumed 1,400 kcal per day. After 6 months, the whey protein group lost almost twice as much body weight (-8%) than the carb group (-4.1%).

Researchers then examined changes in the women’s thighs using magnetic resonance imaging. Results revealed a greater loss of adipose (fat) tissue in the whey group. As a percentage of the total muscle volume, there was also a greater amount of muscle tissue present in the whey group. These results indicate that increased protein intake with whey protein supplementation helped maintain muscle relative to changes in body weight and body fat during calorie reduced diets.


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