The Muscle Mag
Published in the Journal of Applied Physiology and funded by global independent consulting firm Increnovo, the randomized controlled, parallel-group trial investigated the temporal responses of myofibrillar protein synthesis rates and anabolic signaling to resistance exercise alone or in conjunction with protein supplementation in postmenopausal women compared to postabsorptive rates in younger women.
Dr. Ralf Jaeger, managing member at Increnovo, stated, “Our study revealed that the muscle building effects of exercise and nutrition are compromised in menopausal women compared to younger women. Therefore, postmenopausal women require a stronger stimulus to build muscle, either by increasing workout intensity or consuming higher amounts of protein.”
The nutritional supplement used in the study was provided in powdered form by Curves Japan Co. and consisted of whey protein isolate fortified with vitamins C, B1, B2, B3, B5, B6, and B12, as well as minerals calcium, magnesium, iron, zinc, and potassium.
Tackling postmenopausal muscle
Sarcopenia, the age-related loss of muscle mass, poses a significant threat to maintaining health and independence as individuals age. Dr. Jaeger noted that reduced physical activity leads to muscle atrophy, decreased appetite resulting in nutrient deficiencies, and ultimately a decline in quality of life and mortality.
In women, hormonal changes during menopause have been linked to accelerated muscle mass loss, increased visceral fat, and decreased bone density. Postmenopausal females experience sarcopenia and musculoskeletal injuries at a higher rate compared to aging males.
While nutrition and resistance exercise are promoted as lifestyle strategies that promote healthy muscles by stimulating myofibrillar protein synthesis in healthy adults, the study authors emphasized that this characterization has primarily focused on male populations.
Study details
For this study focusing on females, 16 healthy postmenopausal women aged 50 to 79 were recruited to investigate exercise and nutritional strategies to enhance muscle mass regulation in females.
Participants underwent unilateral resistance exercise followed by consumption of either a fortified whey protein supplement or water. They then received infusions of a L-[ring-13C6] phenylalanine tracer along with muscle biopsies before and after treatment at 2 hours and 4 hours in both exercised and non-exercised legs to assess myofibrillar protein synthesis.
The results were compared to a pre-menopausal cohort of women aged 20 to 45 years to examine the effects during the follicular phase of their menstrual cycles.
The researchers concluded that ingestion of 15 g whey protein did not stimulate myofibrillar protein synthesis in postmenopausal women and suggested that additional exercise and nutritional interventions may be necessary to effectively stimulate the skeletal muscle adaptive response.
They also highlighted that post-menopause affects baseline myofibrillar protein synthesis, potentially contributing to a reduced response to anabolic stimuli in females.
Dr. Jaeger emphasized the need for further research to explore these findings and develop nutritional strategies to enhance muscle health in menopausal women and improve the efficacy of protein supplementation in older adults.
He also mentioned plans to publish a paper later this year on the effects of adding nutritional blood flow ingredients to protein in postmenopausal women.
Source: Journal of Applied Physiology
doi: 10.1152/japplphysiol.00886.2023
“Postabsorptive and postprandial myofibrillar protein synthesis rates at rest and after resistance exercise in women with post-menopause”
Authors: Colleen F. McKenna et al.
