The Effects of Whey vs. Pea Protein on Physical Adaptations Following 8-Weeks of High-Intensity Functional Training [HIFT]
Exercise and Nutrition Science Graduate Program, Lipscomb University, Nashville, TN
There is an ongoing debate, whether or not vegan athletes are capable of getting the appropriate amounts of protein through plant-based sources, as compared to non-vegan athletes. Protein quality is also a concern, for performance and training purposes. The purpose of the present pilot study was to compare the effects of whey and pea protein supplementation in conjunction with 8-weeks of HIFT on strength, body composition, muscle thickness, IMTP peak force, IMTP RFD, and WOD performance.
Fifteen HIFT trained men [N=8] and women [N=7] volunteered to participate in this randomized, double-blind training study. All participants had been participating in at least three HIFT workouts per week for at least six months and were free of any physical limitations that may affect performance. Additionally, all participants were free of any medications and performance enhancing drugs, as determined and confirmed by a health and activity questionnaire and all participants agreed to abstain from dietary supplements (e.g., creatine, beta-alanine, amino acids, pre-workout) throughout the duration of their enrollment in the study. Multi-frequency Bioelectrical Impedance Analysis (BIA) was completed at the beginning of and directly after the 8-week intervention using InBody. Participants were matched based on sex and squat 1RM and were randomly assigned to either the whey (men = 4, women = 3) or pea protein (men = 4, women = 4) group. Participants were provided individual bags with their assigned study supplement and consumed their respective supplement twice daily for the entire 8-week study.
In the present study, both groups experienced significant increases in 1RM squat and deadlift strength which supports previous reports of HIFT induced improvements in strength. No differences in strength were observed between whey and pea protein groups. We did not see any significant changes in body composition measurements of any kind following HIFT training regardless of supplemental condition. Moreover, we saw no significant increase in muscle size in either groups as a result of 8-weeks of HIFT
To summarize, our data suggest that whey and pea proteins promote similar strength, performance, body composition, and muscular adaptations following 8-weeks of HIFT
findings also demonstrated that 8 weeks of HIFT resulted in significant improvements in muscular strength for the back squat and deadlift for both groups with no other detected improvements. While limited in participant numbers, this study provides additional evidence regarding suitable alternatives to whey protein for athletes with dietary restrictions. Additionally, it contributes to our further understanding of HIFT and accompanying adaptations from participation in this rapidly growing training mode.