Writing in the journal Frontiers in Nutrition, the researchers detailed the results of a trial that evaluated the biochemical and metabolomic alterations in a group of professional Brazilian soccer players following 10 days of either pea protein or whey protein supplementation.
They noted that outcomes between groups were not significant enough to justify choosing one protein over the other but that the findings highlighted the viability of plant protein as ergogenic aid.
The study was funded by the Carlos Chagas Filho Research Support Foundation in the State of Rio de Janeiro, a public institution that encourages scientific and technological activities to promote socio-cultural development.
The case for pea protein
Proteins play several roles in muscle recovery including increasing muscle protein kinetics and mitochondrial biogenesis, activating signaling proteins in the protein synthesis cascade, reducing unwanted inflammatory responses, and contributing to strength recovery.
Although animal-derived whey protein is more often studied for human performance due to its high branched-chain amino acids (BCAAs) and leucine content, digestibility, and ability to stimulate muscle protein synthesis, the study pointed to pea protein's added value.
“In addition to its valuable amino acid composition, pea protein has a low environmental impact, making it a sustainable, nutritious, and viable alternative for enhanced sports performance, such as in soccer,” the researchers wrote.
Within the plant-protein category, they also indicated that pea protein has a higher digestibility and lower allergenic response than soy protein.
The double-blind, randomized crossover trial randomly assigned 12 male soccer players under the age of 20 years to receive either 0.5 g/kg of pea protein or whey protein for 10 consecutive days. Each group included athletes from various positions to minimize the potential impact of position-specific physical demands on the study outcomes.
Participants consumed their assigned protein after training, starting seven days prior to the test game and for two days post. After a four-day washout period, the athletes switched groups. For exploratory metabolic profiling, blood samples were collected before and after the game, and at 24-, 48- and 72-hour intervals thereafter to test for creatine kinase (CK), aspartate transaminase, alanine transaminase (ALT), lactate (LA), urea, creatinine, and uric acid.
A comparison of biochemical markers showed that the pea protein group had lower CK, LA and ALT right after the game; lower CK at 24- and 28-hours post; and lower ALT at 24-hours post. Of the 48 metabolites analyzed, 22 showed significant differences between the time points, such as amino acids, ketone bodies and glucose metabolism.
The whey protein group registered a significant increase in glutamate and lactate levels between the pre- and post-game, as well as reduced levels of arginine and taurine metabolites post game. No such change was observed in the pea protein group. The study found no significant difference in the results of a countermovement jump test (CMJ) to assess performance readiness or in individual pain perceptions as measured on the Visual Analog Scale (VAS).
“The results obtained suggest that both types of protein supplementation may have contributed to the reduction in cellular damage, with no metabolic alteration compatible with cell damage after 72 h of the game,” the researchers concluded.
The study acknowledged the lack of a placebo control group and suggested that future comparative research include larger sample sizes and incorporate additional time intervals or consecutive games.
Source: Frontiers in Nutrition
“Comparison of the effects of pea protein and whey protein on the metabolic profile of soccer athletes: a randomized, double-blind, crossover trial”
Authros: Luis Lannes Loureiro et al.