Table 4.
Hemoglobin levels and salivary stress biomarkers response among non-anemic athletes during the iron supplementation over four weeks of training exercise regimen compared to placebo.
| Male (Site-1) Variable | Placebo |
Cohen's d |
Fe-treatment |
Cohen's d |
P-Value & F-Value (Between groups) |
Repeated Measure MANCOVA |
||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0W | 2W | 4W | 0W | 2W | 4W | ANCOVA | (Group by Time) | |||
| Hemoglobin (g/dL) | (N = 20) | (N = 21) | 0W–2W: P = 0.790; F = 0.07 | |||||||
| Mean ± sem | 14.34 ± 0.35 | 14.42 ± 0.34# | 14.46 ± 0.31 | 2W: 0.04 | 14.46 ± 0.36 | 14.21 ± 0.32 | 14.67 ± 0.30 | 2W: -0.12 | 0W–4W: P = 0.933; F = 0.01 | P = 0.721; F = 0.18 |
| 95% CI | 13.65–15.04 | 13.74–15.09 | 13.86–15.07 | 4W: 0.07 | 13.75–15.16 | 13.57–14.84 | 14.09–15.26 | 4W: 0.13 | ||
| Salivary α-Amylase (KU/L) | (N = 23) | (N = 26) | 0W–2W: P = 0.072; F = 3.40 | |||||||
| Mean ± sem | 12.91 ± 1.99 | 10.57 ± 1.53 | 13.48 ± 1.85 | 2W: -0.24 | 18.15 ± 3.01 | 19.27 ± 4.27 | 19.85 ± 2.48 | 2W: 0.05 | 0W–4W: P = 0.047; F = 4.16 | P = 0.038; F = 4.58 |
| 95% CI | 9.00–16.82 | 7.57–13.56 | 9.85–17.11 | 4W: 0.05 | 12.26–24.05 | 10.90–27.64 | 10.98–24.71 | 4W: 0.10 | ||
| Female (Site-2) Variable | Placebo (N = 20) |
Fe-treatment (N = 20) |
P- Value & F-Value (Between groups) |
Repeated Measure MANCOVA |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0W | 2W | 4W | 0W | 2W | 4W | ANCOVA | (Group by Time) | |||
| Hemoglobin (g/dL) {N = 18} | ||||||||||
| Mean ± sem | 12.98 ± 0.23 | nd | 13.10 ± 0.22 | 12.26 ± 0.25 | nd | 12.48 ± 0.29 | 0W–4W: P = 0.793; F = 0.07 | NA | ||
| 95% CI | 12.53–13.43 | 12.67–13.54 | 4W: 0.11 | 11.77–12.76 | 11.91–13.06 | 4W: 0.15 | ||||
| Salivary Cortisol (nM) | ||||||||||
| Mean ± sem | 3.00 ± 0.69 | nd | 4.20 ± 0.45 | 2.28 ± 0.28 | nd | 4.52 ± 0.75 | 0W–4W: P = 0.674; F = 0.18 | NA | ||
| 95% CI | 1.65–4.35 | 3.31–5.09 | 4W: 0.40 | 1.73–2.82 | 3.05–5.99 | 4W: 0.65 | ||||
| Salivary IgA (ng/mL) | ||||||||||
| Mean ± sem | 179.9 ± 30.6 | nd | 105.1 ± 30.7 | 143.8 ± 11.1 | nd | 78.2 ± 29.3 | 0W–4W: P = 0.649; F = 0.21 | NA | ||
| 95% CI | 120.0–239.8 | 45.0–165.2 | 4W: 0.45 | 122.1–165.6 | 20.8–135.7 | 4W: 0.48 | ||||
#: N = 19; nd: not determined; N = Number of subjects; sem = Standard error of mean; CI = Confidential interval; ANCOVA = Analysis of covariance; MANCOVA = multivariate analysis of covariance (Repeated measure); Significant P ≤ 0.05; Trending significant P ≤ 0.10; NA = Not applicable; IgA = Immunoglobulin A.; Effect size (Cohen's d).