Timing is everything, but does it really matter? Impact of 8‐weeks morning versus evening iron supplementation in ballet and contemporary dancers

Abstract

The effectiveness of a morning versus evening oral iron supplement strategy to increase iron stores was explored. Ballet and contemporary dancers with serum ferritin (sFer) < 50μg/L (n = 14), were supplemented daily with 105 mg elemental oral iron in either the morning (Fe AM ) or evening (Fe PM ) for 8 weeks. A control group (n = 6) with sFer >50μg/L were given no supplement over the same period. Dancers' sFer were measured at baseline and post-intervention. Assessment of daily training load, dietary intake, and menstruation were made. A significant interaction (p < 0.001) showed the within group sFer change over the 8-week intervention in Fe AM (+25.9 ± 10.5μg/L) and Fe PM, (+22.3 ± 13.6μg/L) was significantly different to CON (−30.17 ± 28.7μg/L; both p = 0.001). This change was not different between Fe AM and Fe PM (p = 0.778). sFer levels within Fe AM and Fe PM significantly increased over the 8-weeks; however, they significantly decreased in the CON group (all p < 0.05). Post-intervention sFer levels were no longer different between the three groups (p > 0.05). Training load, dietary intake, and number of menstrual cycles incurred were similar between Fe AM and Fe PM (p > 0.05). Oral iron supplementation in either the morning or evening appears equally effective in increasing sFer levels in dancers with sub-optimal iron status. KEYWORDS Highlights. 8 weeks of oral iron supplements increases serum ferritin levels in elite dancers.. Dancers not consuming an iron supplement showed a decline in serum ferritin over the 8-week period. . Consuming the iron supplement in either the morning or the evening appeared equally effective in improving serum ferritin stores.

Investigating pre-professional dancer health status and preventative health knowledge

“…As a result, lower energy availability may become chronic, and malnutrition may also become an issue. In a recent study among Australian elite dancers ( 19 ), the reported average daily energy intake was lower than the typical intake reported in studies of elite dancers from the UK and Scotland ( 11 , 18 ) and in particular, lower carbohydrate intakes. Furthermore, over an 8-week period a decline in iron (sFER) levels was observed in these dancers which was attributed to lower than adequate energy intake ( 19 ).…”

Parenteral Iron Therapy: Examining Current Evidence for Use in Athletes

“…Unauthorized distribution is strictly prohibited. [12,23,24]. Although this result is positive and appropriate for individuals who are IDNA or better, an 80% improvement in iron stores for an IDA athlete with sFer <10 µg.L -1 and compromised Hb concentrations would likely still not shift them into the IDNA classification.…”

“…Recent work from our group [1,12,[19][20][21] and others [18], have been exploring factors that impact dietary iron absorption from the gut in relation to exercise. Collectively, this work informs us that there appears to be a peak period for iron absorption within the 30 min either side of exercise [19,21], which is lost if the food/supplement is consumed ≥ 2 h post-exercise [18].…”

“…Collectively, this work provides us with significant strategic approaches to timing iron intake for optimised iron absorption at the gut. However, if we are using these strategies to correct an iron deficiency, it should be considered that the time duration to have a significant impact is relatively long (i. e. 8-12 weeks of oral supplementation to improve iron status by 40-80 % [12,23,24]. Although this result is positive and appropriate for individuals who are IDNA or better, an 80 % improvement in iron stores for an IDA athlete with sFer < 10 µg.L − 1 and compromised Hb concentrations would likely still not shift them into the IDNA classification.…”

Iron Absorption in Highly Trained Male Runners: Does it Matter When and Where You Eat Your Iron?

“…However, this is likely of limited practical benefit in the context of iron supplementation. Indeed, despite clear evidence showing enhanced absorption occurs in the morning (compared with evening) as a result of diurnal variations in hepcidin (6,7), the practical implementation of this approach in a group of female dancers over an 8-wk period showed a comparable increase in serum ferritin, regardless of whether they supplemented in the morning or afternoon (25). Therefore, although strategically manipulating the timing of iron supplementation may be beneficial because of its increased fractional iron absorption, over the duration of a full supplementation schedule small changes in iron bioavailability may result in similar changes to iron status.…”