A new study published in the Journal of Physiology has shown that obesity makes it more difficult for a person to build muscle. The research indicated that a person suffering from obesity who does resistance exercise will not increase muscle mass at the same rate as someone who is within a healthy body mass index (BMI).
Head of the research team, Nicholas Burd, worked with Joseph Beals, a graduate student in the Division of Nutritional Sciences, University of Illinois at Urbana‐Champaign, felt their study took the understanding of this impact to a new level.
Studying How We Build Muscle
The study was titled “Altered anabolic signaling and reduced stimulation of myofibrillar protein synthesis after feeding and resistance exercise in people with obesity. In it, Burd stated that “Our new study goes further, showing there is an obesity-related impairment in building new muscle proteins in the fed state after a weightlifting session.”
The team worked with the participation of nine people who were obese, with a BMI of 30 or higher. They also worked with nine people within the healthy body mass range. These individuals were all within the age range of 20 to 23 years.
The researchers ruled out participants who were not sufficiently active ahead of the study. To do this, the participants were required to take standardized health surveys. Once the participants’ body composition, fitness capability to take part in a weighted leg extension exercise to build muscle, and glucose tolerance was determined, the researchers moved ahead with the study.
They started infusing stable-isotope-labelled phenylalanine among all study subjects. In this way, the researchers were better capable of monitoring the levels of amino acids in the muscles and blood of the participants throughout the length of the research.
The participants were then required to have leg biopsies taken before they performed resistance exercises with their non-biopsied legs. The resistance exercise consisted of four sets of 10 to 12 reps. This let them observe the way the body would build muscle.
Muscle Building Findings
The research found that the participants with obesity experienced reduced ability to build muscle when compared to the participants in the normal body mass category. This post-workout muscle building and repair impairment could make it more difficult for people with obesity to be able to burn fat and, therefore, achieve a healthier body mass.