Whey growth factor extract fails to increase muscle strength in experienced resistance trainers: RCT

By Cheryl Tay

- Last updated on GMT

WGFE was shown to help increase strength, but not in men experienced in regular resistance training. ©iStock
WGFE was shown to help increase strength, but not in men experienced in regular resistance training. ©iStock
Consumption of whey growth factor extract (WGFE) in addition to whey protein isolate offers few benefits to men who are not new to resistance exercise training, according to a study led by the University of South Australia.

Researchers found that men who had been exercising regularly for at least half a year did not experience the same beneficial effects of WGFE supplementation that had been observed in a previous study assessing men who had only just begun exercising regularly.

WGFE is a concentrated protein source from cow’s milk that consists primarily of lactoperoxidase (62%) and lactoferrin (16%) proteins.

The new study involved 46 men between the ages of 18 and 30, who had been engaging in two or more resistance training sessions a week for at least six months before being recruited.

They were divided into two groups: each participant had to consume 20g of whey protein isolate every day, but those in one group were also supplemented daily with 1.6g of cellulose each, while those in the other were each supplemented daily with 1.6g of WGFE.

They were also placed on a 12-week resistance training programme with 24 to 72 hours between training sessions.

Subsequently, the study found that “supplementation with 1.6g / day of WGFE during 12 weeks of resistance training in resistance-trained young men did not enhance increases in muscle strength or lean tissue mass”​.

Furthermore, despite the 34% increase in the “primary outcome of incline leg press strength”​, strength improvements were ​similar in both the control and treatment groups and therefore, not related to WGFE supplementation.

Diminishing gains

On the other hand, a previous study that had assessed untrained men showed greater strength increases in subjects who had been supplemented with WGFE.

The study attributed the disparity in its results to the fact that gains in muscular strength can diminish as training experience increases.

Another possible reason for the difference in the results of the two studies is the dosage of WGFE: the previous study had supplemented each of its participants with 2g of WGFE a day instead of 1.6g. In this study, the dosage was decreased to increase the commercial viability of the product.

As such, the study concluded that daily supplementation with 1.6g of WGFE during resistance exercise training “might provide an advantage for increasing strength in untrained individuals (i.e., novices) or individuals who are less well-adapted to training, but not for individuals who are already well-adapted to strength training”​.


Source: Journal of Sports Science and Medicine

Volume 16(2); 2017 Jun

"No Effect of a Whey Growth Factor Extract during Resistance Training on Strength, Body Composition, or Hypertrophic Gene Expression in Resistance-Trained Young Men"

Authors: Michael J. Dale, et al.

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