The new results support findings of previous studies which found this ingredient can improve body composition, strength and power in men, therefore showing the benefits are achievable between genders.
Many benefits associated with physical activity are largely influenced by sex hormones. Testosterone, for example, stimulates protein synthesis and inhibits protein degradation within muscles, leading to promotion of muscle growth and increases in muscle strength, whereas oestrogen can exert a broadly analogous effect by increasing the anabolic response to exercise in females.
The herb Trigonella foenum-graecum, known as fenugreek, contains a number of active constituents, including the amino acid 4-hydroxyisoleucine, saponins, and numerous other phytochemicals with varying biological and pharmacological activities, and has been shown to exert positive effects in diabetes, inflammation, and some types of cancer.
However, studies using fenugreek specifically in females, have mainly focused on the amelioration of menopausal symptoms.
Libifem, an extract of fenugreek, standardised to 50% of furostanol saponins, has been shown to bind to E2 receptors and induce expression of E2-responsive genes and improve sexual function in both pre- and postmenopausal females.
The researchers aimed to fill the large data gap in how this supplement impacts female athletes' muscle strength and endurance, as well as body composition, leg power, muscle recovery, pathological markers, and quality of life in response to an 8-week bodyweight resistance training program.
They hypothesised that participants on Libifem would show an increase in muscle strength, power, and endurance, which would, in turn, positively impact body composition at a faster rate than a placebo. It was also hypothesised that participants on the higher dose of Libifem would elicit greater improvements in performance.
They found daily supplementation with 600 mg dose of Libifem in conjunction with resistance training significantly increased strength and lean mass and decreased total fat mass and trunk fat mass.
They conclude: "The major outcomes from this study can be applied to women's resistance training, as there is a need for natural products that benefit body composition. Despite the potential variables involved in female-only exercise studies, the beneficial effects of Libifem following resistance training were evident, and the product was well tolerated.
"Therefore, this study has the potential to increase the exercising capabilities and alter the physique of females partaking in resistance-based exercise—an area of increasing popularity, but typically under targeted by both science and commercial products."
Mariko Hill, Global Innovation Manager at Gencor, says this study is groundbreaking in regard to the fact that many clinical studies, particularly in sports nutrition, tend to be researched on only the male population.
"With many active females having symptoms associated with RED-S (Relative Energy Deficiency in Sport), such as loss of menstrual cycle, low bone mineral density, low mood, low energy levels and more, interventions that can support these outcomes may be a unique way to support the health and performance of athletes.
"Libifem has been clinically proven to optimise levels of oestrogen and testosterone in the body, within normal human physiological limits. This could be a unique ingredient that can support those athletes with suboptimal levels of reproductive hormones, muscle mass and energy. "
Speaking about how the study will extend innovation opportunities with the ingredient, she adds: "This study would allow formulators to consider using Libifem in sports nutrition applications such as [whey/vegan] protein powders, BCAA's and multi-ingredient capsules targeting women's health and performance."
Interested in female athlete studies?
NutraIngredients will delve into research regarding how supplements can support the specific health and performance of female athletes during the Active Nutrition Summit, taking place in Amsterdam this October.
The three day conference will start with an afternoon of presentations and panel discussions all focused on the female athlete and active consumer, with insights into the latest science and new innovations in this space.
The conference will also delve into the topics of healthy ageing, young athletes, cognitive health, online marketing and personalised nutrition.
Fenugreek and females
Fenugreek has been shown to increase free oestrogen and testosterone levels in females and testosterone in males , via re-partitioning mechanisms including the displacement of testosterone from relatively low-affinity binding sites on, i.e., serum albumen. These pharmacological effects would be expected to improve aspects of muscle function.
A previous study on females undertaking resistance training with fenugreek supplementation showed that completing either two or three resistance training sessions per week showed similar increases in muscle strength and lean soft tissue mass, with those in the higher-frequency group showing improvements in body mass. However, the full effects of fenugreek on females and exercise performance have not yet been studied.
Exercise studies in females present a number of challenges not typically encountered in male-only studies. The most confounding factor in female-only studies is the potential for hormone shifts linked to the menstrual cycle and menopause which have the potential to influence cardiovascular and respiratory systems, thermoregulation, and injury/repair mechanisms.
The study
This study was a double-blind, randomised, placebo-controlled, multi-site (Brisbane and Gold Coast, Australia) interventional study conducted over an 8-week treatment duration, utilising two active and one placebo group.
One hundred and twenty-nine participants (aged 25–45 years) were recruited and enrolled into the study. Participants underwent a health assessment that included lifestyle, current medications, physical assessment, and medical history. Muscle strength, power, endurance, body composition, and quality of life were also assessed, plus the participants' blood was collected for baseline analysis. Once all baseline measures were successfully completed, the participants were enrolled in the trial and randomly allocated to the placebo comparator group or one of the two active intervention groups (300 mg of Libifem/day or 600 mg of Libifem/day).
The participants were asked to take the allocated product and complete a resistance training program. They completed three training sessions per week during weeks 1–3 and 5–7 and two sessions during assessment weeks 4 and 8.
At the mid-point (week 4), the participants were assessed on resting heart rate (HR) and blood pressure (BP); anthropometric measurements including height, weight, waist, and hip circumference; 1RM leg press and bench press; and 80% of 1RM bench leg press and bench press repetitions to fatigue.
Upon completion of the study (week 8), an assessment identical to baseline was completed.
After drop-outs, the authors analysed results for 84 participants.
No significant differences between the active treatment and placebo groups at baseline for age, anthropometric measures, pathology, lifestyle factors, quality of life, or exercise measurements were noted. No significant differences for exercise session compliance were reported.
The resulting data revealed daily supplementation with 600 mg dose of Libifem in conjunction with resistance training significantly increased 1RM values and lean mass compared with resistance training alone (placebo) in females. The 600 mg Libifem group decreased total fat mass (−0.96 kg) and trunk fat mass (−0.59 kg), increased lean mass (+1.09 kg), and improved 1RM leg press compared with the placebo group.
In both the 300 mg and 600 mg Libifem groups, significant intra-group changes for total fat mass, trunk fat mass, and lean mass from baseline to week 8 that did not occur in the placebo group were identified.
Supplementation had no significant impact on testosterone levels in any group, with all values remaining within the normal range.
Regarding future areas of research, the authors note that given the different mechanisms of action of natural and food-based products, it is possible that multiple supplements may have an additive effect offering greater advantages to those who know the science.
They say: "The effect that combining multiple supplements together may have is an area of increasing interest and a potential focus for future studies."
They add that another area that needs further research is how the menstrual cycle might impact the effects of this supplement.
"Testing of the hormone levels or monitoring the menstrual cycle phases may have assisted in evaluating the true effects of Libifem and how testosterone levels may have improved or affected the measured outcomes. Further research including variables to account for these changes in hormones may be beneficial to assist in the understanding of this phenomenon," the report states.
Source: Frontiers in Sports and Active Living
https://doi.org/10.3389/fspor.2023.1207013
Libifem (Trigonella foenum-graecum) in conjunction with exercise on muscle strength, power, endurance, and body composition in females aged between 25 and 45 years