Woods 2014.

Methods	RCT; parallel‐group (phase III). Study conducted in a single centre
Participants	Elite athletes with non‐anaemic iron deficiency (as determined by Hb > 120 g/L and serum ferritin between 30‐100 mcg/L). Patients taking oral iron therapy were excluded from the study.
Interventions	Patients randomised to receive dosing of IV iron (100 mg ferric carboxymaltose) or placebo (0.9% sodium chloride) every 2 weeks for 4 weeks (3 doses)
Outcomes	Primary outcome was improvement in tHb mass at the end of follow‐up. Additional secondary outcome measures included VO2 peak, Brunel Mood Scale and BFI as well as Hb, ferritin and TSAT. We could not extract data on QoL scores due to absence of baseline data and presentation of data not amenable to extraction. VO2 peak data for baseline measurement was obtained after the first dose of iron was given and hence we excluded this metric.
Study funding arrangements	Study funded by a University of Canberra grant for post‐doctoral fellowship research. The funder had no role in study design, data collection, data analysis, decision to publish or preparation of the manuscript.
Author conflicts of interest	No conflicts of interest declared
Sample size	14 participants were randomised 1:1 to receive the intervention (n = 7) or control (n = 7) treatment
Notes	Study was not registered in a public trials registry
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: no reference made to the randomisation technique, beyond a statement that it was undertaken
Allocation concealment (selection bias)	Unclear risk	Comment: given a random method was allegedly used, presumably the potential for allocation concealment existed. However, as study authors made no specific reference to methods used, the risk of bias is unclear
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Throughout each injection, the participant’s arm was shielded using a screen with the injection solution prepared out of sight. In addition to all athletes, all research staff associated with the testing and training sessions were blinded to the treatment groups and were unable to access blood results, nor preside over the injections. Thus, only the medical staff administering the injections had access to grouping allocation information."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Throughout each injection, the participant’s arm was shielded using a screen with the injection solution prepared out of sight. In addition to all athletes, all research staff associated with the testing and training sessions were blinded to the treatment groups and were unable to access blood results, nor preside over the injections. Thus, only the medical staff administering the injections had access to grouping allocation information."
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: all participants completed follow‐up with no missing data. However, as we could not extract some data due to the style of presentation, and the lack of baseline data, we cannot give a judgement of low risk.
Selective reporting (reporting bias)	Unclear risk	Comment: all stated outcomes in the article were reported, but as the study was not prospectively registered and we did not see the, the risk of bias remains unclear.
Other bias	Low risk	Comment: only issue is the lack of information regarding prospective registration and lack of a protocol. This was addressed in previous domain.

ADP: adenosine diphosphate; BFI: Brief Fatigue Inventory; BNP: B‐type natriuretic peptide; CABG: coronary artery bypass graft; CPET: cardiopulmonary exercise testing; EQ‐5D‐5L: Euroquol 5 dimension, 5 level quality‐of‐life measure; Hb: haemoglobin; HRQoL: health‐related quality of life; IQR: interquartile range; IRLS: International Restless Legs Syndrome Rating Scale; ITT: intention‐to‐treat; IV: intravenous; KCCQ: Kansas City Cardiomyopathy Questionnaire; LVEF: left ventricular ejection fraction; MLHFQ: Minnesota Living with Heart Failure Questionnaire; NAID: Non‐Anaemic Iron Deficiency; NYHA: New York Heart Association; PCR: polymerase chain reaction; QoL: quality of life; PHQ‐9: Patient Health Questionnaire (depression); RCT: randomised controlled trial; SD: standard deviation; SF‐12: 12‐item short form survey; tHb: total haemoglobin; TSAT: transferrin saturation; TTE: transthoracic echocardiogram; VO₂ max: peak oxygen consumption; WHO: World Health Organization; 6MWT: 6‐metre walk test;