There were no differences in body mass change between the WHEY and CON groups even though both groups lost body mass (p<.05), however WHEY group maintained LBM while the CON group lost (p<.05), and the WHEY group lost FM (p>.05) and the CON group did not, though the change in FM between groups was not different.
Both the WHEY and CON (p<.05) groups significantly increased lower body strength.. The WHEY group increased upper body strength (p<.05) while the CON did not change. Both groups (P<.05) increased lower body repetitions to fatigue with the increase greater in the CON group (p<.05).
The CON group also increased upper body repetitions (P<.05) while WHEY did not. WHEY group lost body mass, composed of FM while CON also experienced a loss in body mass, but this loss was due to decrease in LBM. Neither group experienced a loss in muscle performance, with the WHEY group tending to show improvement in strength and CON group in endurance. These data indicate WHEY supplementation; compared to CHO supplementation, during a caloric-restricted “cut” diet can assist in maintaining LBM while allowing for the loss of FM.
Both the whey and CON groups reduced overall body mass after the eight-week intervention, attesting to the effectiveness of the hypocaloric diet. However, the whey group experienced a decrease in fat mass that was significantly different from pre-trial values, and from the CON group, indicating that the whey supplement was more effective than the carbohydrate supplement at promoting fat loss.
This finding is consistent with previous studies that demonstrated a decrease in overall body mass and fat mass when comparing the consumption of a whey protein supplement with a carbohydrate supplement within a group of healthy, resistance-trained men (3).
It is possible that the CON group did not lose fat mass because carbohydrate supplementation stimulated a greater insulin release, which is not as effective as protein supplements in stimulating muscle anabolic pathways (7).
We anticipated an increase in lean muscle mass after the conclusion of the resistance training and whey supplementation period, however; only the whey group maintained lean body mass (0±0.8 kg) whereas the CON group decreased lean body mass (0.9±0.1 kg). It is possible that the decrease in lean mass can be attributed to decreased myofibrillar synthesis in the CON group, potentially a result of a lower consumption of dietary protein, combined with a muscle-damaging resistance-training program.
Hector et al. (2015) found that whey protein supplementation post- exercise attenuated the decline in post-prandial rates of myofibrillar protein synthesis after weight loss, which was important in preserving lean mass during weight loss interventions (8). Similarly, Joy et al. (2013) found that a whey protein supplement, in addition to a resistance- training program, in resistance-trained males was effective in optimizing muscle protein accretion and muscle fitness (9).
Further, it is also possible that the WHEY decreased muscle protein degradation by providing enough available amino acids that the body didn’t have to break muscle down to provide the necessary amino acids (16). Thus, the lack of a whey protein supplement may have allowed the post-exercise decline in myofibrillar protein synthesis in the CON group.
Previous studies using whey protein supplements have demonstrated that protein supplementation is more effective than carbohydrate supplementation at maintaining lean body mass and improving overall body composition (3,4,13,22) Willoughby et al. (2007) found that a combined protein supplement (whey and casein) was effective in improving muscle mass and strength, and improving overall body composition (22).
Similarly, Candow et al. (2006) found that a thrice-daily consumption of a whey protein supplement in healthy, young males and females was effective in increasing lean tissue mass and improving body composition (3).
Moringa has many benefits for health and weight loss
Protein quality is also an important determinant of lean body mass responses to resistance training (20). Numerous researchers have demonstrated the ergogenic effects of whey protein on lean muscle mass in both untrained and trained individuals.
Candow et al. (2006) illustrated that whey protein supplementation increased the ratio of protein synthesis to degradation post- exercise in young untrained males and females. In a study conducted on healthy young resistance-trained males, a whey nutritional intervention increased protein accretion and lean muscle mass while also improving muscle function (4).
Further, researchers have found that daily supplementation of soy lowered circulating testosterone levels, whereas whey supplementation blunted cortisol response post-exercise. Therefore, whey may provide a more anabolic environment than soy because of its rapid rate of absorption and ability to blunt the cortisol response post-exercise (10).
The preservation of or increase in lean mass continues to be an important research topic, especially for athletes trying to improve body composition while maintaining performance and for older adults who risk obesity or age-onset sarcopenia and other age-related diseases (5).
Providing these persons with adequate and high quality protein, such as whey protein, can stimulate myofibrillar protein synthesis, influence anabolic hormones and in turn preserve lean body mass (5,18). Our data suggest that whey protein supplementation in individuals attempting to lose weight via caloric restriction can achieve maintenance of lean tissue mass while experiencing a loss of fat mass.
Eight weeks of resistance training combined with a whey protein supplement did not elicit a significant increase in RMR. Interestingly, the whey group decreased RMR compared to baseline values, whereas the CON group maintained RMR over the same time span. Variation in RMR is largely determined by muscle mass, where increases in muscle mass increases RMR because the muscle consumes a greater amount of energy at rest, compared to fat tissue (7).
The CON group demonstrated a decrease in lean mass without a concurrent decrease in RMR, possibly due to the fact that they only decreased their lean mass by 0.9 kg, which is only 0.5% of total mass (mean = 179.1 kg). Therefore, the decreased lean mass would not contribute to the change in RMR to a significant degree.
Other researchers have shown that protein supplementation in conjunction with resistance training is effective in increasing RMR above baseline values. Hambre et al. (2012) demonstrated that after a 12-week resistance- training and protein supplementation (33g whey protein/day) program in healthy males, both RMR and lean tissue mass were increased similarly (7). However, the use of a hypocaloric diet in our study makes our findings unique, and can partially explain the lack of observed changes in RMR.
Muscle Strength and Endurance
There is a growing research interest into the anabolic benefits of protein supplements compared to a carbohydrate supplement during resistance training. Willoughby et al. (2007) indicated that whey/amino acid supplementation resulted in greater increases in upper body (bench press) and lower body (leg press) strength, when compared to a carbohydrate supplement (22).
However, both of the aforementioned studies utilized multiple-ingredient protein supplements and caloric neutral diets, whereas the current study utilized a whey protein supplement in conjunction with a hypocaloric diet. After an eight week period, the whey group showed small improvements in both upper body and lower body strength, whereas the CON group only showed improvements in lower body strength. Interestingly, the strength values in the whey group were not significantly greater than the values from the CON group in lower body strength despite the change in the whey group being twice that of the CON group.
These results may be attributed to the specific effect of whey protein on muscle fibers. Ingestion of whey protein and its constituent amino acids stimulates anabolic hormone release and promotes the synthesis of muscle fibers, especially Type II muscle fibers, which enables powerful movements that promote strength rather than endurance outcomes (2,18).
It should be noted that placebo groups were consuming protein in their diets, so they too would be able to promote muscle fiber hypertrophy, though to a lesser extent. Further, these subjects were already experienced in weight training, so the type of training (this was not assessed as an inclusion criteria) they were accustomed to could explain the presence or absence of strength/endurance changes.
Other studies have demonstrated that a combination of whey with other protein supplements, such as casein and free amino acids (i.e. leucine) is more effective than an isolated whey supplement or an isocaloric carbohydrate supplement in promoting muscle anabolism and muscle strength, though with inconsistent results (2,3,11,17,18). A study by Cornish et al. (2009) illustrated the muscular strength benefits of a conjugated linoleic acid/creatine/whey (CCP) protein supplement when compared to creatine/placebo (CP) and whey/placebo (P) supplement groups.
Increases in bench press strength, leg press strength, and lean tissue mass were greater in the combined group (CCP) than the isolated creatine (CP) or whey (P) groups (6). Burke et al. (2001) compared a whey/creatine monohydrate supplement against an isolated whey supplement, and reported that the subjects who consumed the whey/creatine supplement experienced greater increases in lean tissue mass and muscular strength than the whey or placebo group (3).
Andersen et al. (2005) illustrated that the ingestion of a protein supplement blend (whey, casein, egg white, glutamine) one hour before and after exercise combined with a 14-week resistance program was more effective than an isocaloric carbohydrate in improving muscle performance as tested by a vertical jump (1).
Some researchers contend that a whey supplement combined with amino acids elicits the greatest beneficial effects on muscle protein synthesis and strength. Verreijen et al. (2015) found that a supplement with high whey protein, leucine, and vitamin D enriched content preserved muscle mass during intentional weight loss (defined as training in addition to a hypocaloric diet) in obese older adults (18).
However, in contrast to the aforementioned study conducted by Verreijen et al (2015), Mielke et al. (2009) compared muscular strength benefits from a whey/leucine supplement against a carbohydrate placebo and non-supplement group, and found that the gains in muscular strength were equivalent between the carbohydrate and the whey/leucine groups (12). Similarly, Spillane et al (2014) found that the peri-exercise ingestion of a multi-ingredient protein nutritional supplement (39g maltodxtrose, 7g whey, 4g creatine monohydrate) was not effective in preferentially improving body composition, muscle performance, or muscle protein synthesis (17).
The variability in experimental factors such as the quantity of the supplements, the type of supplements, the timing of ingestion, training status, intensity of training, and external dietary intake (iso-, hyper- or hypo-caloric) make direct comparisons of these studies difficult (12).
In this study, an isolated whey protein supplement promoted a greater loss in fat mass and preservation of lean body mass and (lower body) muscular strength than a carbohydrate placebo after eight weeks of heavy resistance training and a reduced-calorie diet. While it is not novel that a protein supplement can be more effective than a carbohydrate supplement at maintaining muscle mass and performance, what is unique is realizing these changes during a reduced calorie diet.
The data from this study can be directly implemented by sports performance coaches, athletic trainers, sport coaches, fitness trainers, athletes and active adults who engage in resistance training and are concerned with body composition. Many times athletes are asked to lose body mass in an attempt to improve performance, but this often leads to a loss of muscle mass, and hence poorer performance.
The results of this study indicate that an eight-week progressive strength-training program performed in conjunction with a hypo-caloric diet and a whey protein supplement can maintain lean body mass while promoting loss of fat mass. While applicable to many athletes, this information may be especially valuable to wrestlers, boxers, mixed martial artists, and physique athletes (i.e. body builders, fitness competitors, etc.) who need to maintain lean mass and performance while still “making weight.”