Influence of iron supplementation on fatigue, mood states and sweating profiles of healthy non-anemic athletes during a training exercise: A double-blind, randomized, placebo-controlled, parallel-group study

• Published in: Contemporary clinical trials communications Vol. 32; p. 101084
• Main Authors: Kapoor, Mahendra P., Sugita, Masaaki, Kawaguchi, Mikiko, Timm, Derek, Kawamura, Aki, Abe, Aya, Okubo, Tsutomu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.04.2023; Elsevier
• Subjects: Exercise; Fatigue; Iron supplementation; Non-anemic athletes; Profile of mood states (POMS); Salivary biomarkers; Sweating; Iron supplementation; Exercise; Sweating; Non-anemic athletes; Salivary biomarkers; Fatigue; Profile of mood states (POMS)
• ISSN: 2451-8654; 2451-8654
• DOI: 10.1016/j.conctc.2023.101084

Iron is specifically important to athletes, and attention has grown to the association between sports performance and iron regulation in the daily diets of athletes. The study presents new insights into stress, mood states, fatigue, and sweating behavior among the non-anemic athletes with sweating exercise habits who consumed a routine low dose (3.6 mg/day) of iron supplementation. In this double-blind, randomized, placebo-controlled, parallel-group study, both non-anemic male (N = 51) and female (N = 42) athletes were supplemented either with a known highly bioavailable iron formulation (SunActive® Fe) or placebo during the follow-up training exercise period over four weeks at their respective designated clinical sites. The effect of oral iron consumption was examined on fatigue, stress profiles, as well as the quality of life using the profile of mood state (POMS) test or a visual analog scale (VAS) questionnaire, followed by an exercise and well-being related fatigue-sweat. Also, their monotonic association with stress biomarkers (salivary α-amylase, salivary cortisol, and salivary immunoglobulin A) were determined using spearman's rank correlation coefficient test. Repeated measure multivariate analysis of variance (group by time) revealed that the total mood disturbance (TMD) score was significantly lower (P = 0.016; F = 6.26) between placebo and iron supplementation groups over the four weeks study period among female athletes. Also, a significant reduction in tired feeling/exhaustion after the exercise (P = 0.05; F = 4.07) between the placebo and iron intake groups was noticed. A significant within-group reduction (P ≤ 0.05) was noticed in the degree of sweat among both male and female athletes after 2 and 4 weeks of iron supplementation, while athletes of the placebo intake group experienced a non-significant within-group reduction in the degree of sweat. Overall, the result indicates routine use of low dose (3.6 mg/day) iron supplementation is beneficial for non-anemic endurance athletes to improve stress, mood states, subjective fatigue, and sweating conditions. [Display omitted] •Sweat iron lose is crucial for non-anemic endurance athletes during exercise sweating.•Effect of iron consumption was examined on fatigue and stress using POMS test and VAS scale.•The routine use of low dose (3.6 mg/day) iron supplementation is beneficial for athletes.•Iron supplementation can help maintain and improve the wellness of non-anemic athletes. Simple Summary: Iron deficiency is frequent among athletes. Low dietary iron intake can have a negative impact on physical performance and endurance in non-anemic males and more often in females. Also, the increased sweat iron loss is important in iron balance consideration in athletes to prevent a decline in iron status during training. In this study, we investigate the effect of a routine low dose of iron supplementation on the fatigue, mood states, and sweating behavior of both non-anemic male and female athletes. It is recommended that even low-dose iron supplementation (3.6 mg/day) could be helpful to maintain and ameliorate the overall wellness of non-anemic athletes engaged in endurance exercise, as well as individuals with marked sweat losses due to heavy physical work.