Table 3.
Ultra-marathon-induced changes in blood acid base balance, iron status and levels of electrolytes, glucose and lactate
| Variable | Reference range | Pre-race | 12 h running | 24 h running | 48 h running | 24 h post-race | 48 h post-race | ANOVA results | |
|---|---|---|---|---|---|---|---|---|---|
| pH | 7.350–7.450 | 7.394 ± 0.011 | 7.428 ± 0.026* | 7.440 ± 0.016** | 7.462 ± 0.023*** | 7.440 ± 0.016*** | ND | F 4,24 = 13.0 | p < 10 −3 |
| pCO2 [mmHg] | 35–45 | 43 ± 2 | 38 ± 4.5** | 38 ± 2** | 36 ± 2*** | 41 ± 1** | ND | F 4,24 = 15.3 | p < 10 −3 |
| Ca2+[mmol/l] | 1.13–1.30 | 1.22 ± 0.03 | 1.19 ± 0.07 | 1.18 ± 0.05* | 1.15 ± 0.02*** | 1.17 ± 0.02* | ND | F 4,24 = 10.2 | p = 0.005 |
| Na+[mmol/l] | 135–145 | 141 ± 2 | 140 ± 2 | 138 ± 3 | 137 ± 3* | 140 ± 4 | 138 ± 1** | F 5,30 = 3.76 | p = 0.009 |
| K+ [mmol/l] | 3.5–5.1 | 4.6 ± 0.2 | 5.1 ± 0.6 | 5.3 ± 0.8 | 5.3 ± 0.6 | 4.7 ± 0.4 | 4.6 ± 0.4 | F 5,30 = 3.84 | p = 0.008 |
| Glucose [mmol/l] | 3.9–5.8 | 5.3 ± 0.9 | 4.9 ± 1.2 | 5.9 ± 0.9 | 6.1 ± 0.8 | 5.4 ± 0.6 | 5.0 ± 0.7 | F5,30 = 2.47 | p = 0.055 |
| Lactate [mmol/l] | 0.5–2.4 | 2.4 ± 0.5 | 2.3 ± 0.5 | 2.1 ± 0.5 | 2.0 ± 0.7 | 1.6 ± 0.4*** | ND | F 4,24 = 3.50 | p = 0.022 |
| Fe [μmol/l] | 10.0–30.8 | 15.0 ± 5.2 | 8.1 ± 5.3 | 14.5 ± 4.8 | 5.9 ± 1.7* | 12.5 ± 8.4 | ND | F 4,24 = 3.80 | p = 0.016 |
| Ferritin [μg/l] | 22–275 | 49 ± 30 | 64 ± 39* | 81 ± 47** | 136 ± 66** | 125 ± 45*** | ND | F 4,24 = 22.6 | p < 10 −3 |
| sTfR [mg/l]a | 0.83–1.76 | 1.13 ± 1.02 | 1.11 ± 0.96 | 1.01 ± 0.84* | 0.95 ± 0.79*** | 0.86 ± 0.68*** | ND | F 4,24 = 34.7 | p < 10 −3 |
| sTfR/log10Ferritin index | 0.72 ± 0.15 | 0.66 ± 0.14*** | 0.56 ± 0.13*** | 0.46 ± 0.11*** | 0.42 ± 0.08** | ND | F 4.24 = 58.2 | p < 10 −3 | |
sTfR soluble transferrin receptor, * p < 0.05, ** p < 0.01, *** p < 0.001 versus the respective pre-race value; the significance levels shown with asterisks refer to p values with the sequential Bonferroni–Holm correction. ND not determined, statistically significant ANOVA results are shown in boldtype