TABLE 5.
Repeated sprint protocol performance, gas exchange, and perception.
| Variable | LCHF | HCLF | P-value; η 2p | ||||||
|
Pre Day –1 |
Post Day 31 |
Change Mean (95% CI) |
Pre Day –1 |
Post Day 31 |
Change Mean (95% CI) |
Treatment | Time | Interaction | |
| Total time (sec) | 1267.0 ± 90.3 | 1236.1 ± 69.2 | –30.9 (84.9, –23.1) | 1267.1 ± 93.3 | 1254.0 ± 101.2 | –13.1 (32.2, –6.0) | 0.695; 0.018 | 0.064; 0.331 | 0.556; 0.040 |
| Mean carbohydrate oxidation (g/min) | 3.13 ± 1.08 | 1.44 ± 0.84#*† | –1.69 (2.7, 0.7) | 3.66 ± 1.19 | 3.66 ± 0.52#* | –0.00 (0.8, –0.8) | 0.004; 0.611 | 0.011; 0.532 | 0.023; 0.456 |
| Mean fat oxidation (g/min) | 0.75 ± 0.36 | 1.44 ± 0.41#*† | 0.69 (–0.3, –1.1) | 0.61 ± 0.31 | 0.53 ± 0.22#* | –0.08 (0.4, –0.2) | 0.002; 0.683 | 0.012; 0.526 | 0.007; 0.577 |
| Heart rate (b.min-1) | 160.5 ± 9.2 | 163.2 ± 13.5 | 2.64 (2.7, –8.0) | 162.0 ± 7.6 | 159.6 ± 8.4 | –2.44 (5.0, –0.2) | 0.700; 0.017 | 0.931; 0.001 | 0.125; 0.242 |
| Mean VO2 (ml/kg/min) | 45.8 ± 5.75 | 48.9 ± 3.89 | 3.09 (–0.3, –5.9) | 46.4 ± 8.02 | 46.1 ± 5.15 | –0.31 (3.8, –3.2) | 0.457; 0.063 | 0.259; 0.139 | 0.070; 0.320 |
| Mean VO2 (L/min) | 3.87 ± 0.41 | 3.99 ± 0.41 | 0.12 (0.1, –0.3) | 3.86 ± 0.49 | 3.80 ± 0.50 | –0.06 (0.3, –0.2) | 0.366; 0.091 | 0.662; 0.022 | 0.191; 0.182 |
| Mean VCO2 (L/min) | 3.34 ± 0.39 | 3.20 ± 0.35 | –0.14 (0.5, –0.2) | 3.53 ± 0.57 | 3.50 ± 0.42 | –0.03 (0.3, –0.2) | 0.083; 0.297 | 0.388; 0.084 | 0.504; 0.051 |
| Mean VE (L/min) | 107.0 ± 10.4 | 106.8 ± 11.3 | –0.18 (5.0, –4.7) | 106.9 ± 13.0 | 106.7 ± 10.2 | –0.24 (8.7, –8.2) | 0.960; 0.000 | 0.918; 0.001 | 0.990; 0.000 |
| Mean RR (bpm) | 40.8 ± 7.51 | 39.7 ± 6.88 | –1.08 (2.6, –0.5) | 40.3 ± 7.82 | 40.7 ± 7.38 | 0.41 (2.1, –2.9) | 0.796; 0.008 | 0.627; 0.027 | 0.272; 0.132 |
| Mean RER | 0.86 ± 0.05 | 0.80 ± 0.04#*† | –0.06 (0.15, 0.05) | 0.91 ± 0.05 | 0.92 ± 0.04#* | 0.01 (0.0, –0.1) | 0.001; 0.716 | 0.005; 0.596 | 0.010; 0.536 |
| Session RPE | 7.20 ± 1.03 | 7.10 ± 1.37 | –0.10 (0.8, –0.6) | 7.10 ± 0.99 | 7.60 ± 1.26 | 0.50 (0.0, –1.0) | 0.534; 0.044 | 0.399; 0.080 | 0.081; 0.300 |
| RPE-O | 7.16 ± 0.93 | 6.87 ± 1.08 | –0.29 (0.7, –0.1) | 6.91 ± 0.84 | 7.16 ± 0.75 | 0.25 (0.3, –0.8) | 0.927; 0.001 | 0.894; 0.002 | 0.095; 0.279 |
| Session affect | 0.50 ± 2.55 | 0.00 ± 2.75# | –0.50 (1.1, –0.1) | 0.30 ± 3.05 | –0.10 ± 3.07# | –0.40 (1.1, –0.3) | 0.678; 0.020 | 0.041; 0.386 | 0.823; 0.006 |
| Affect | 0.16 ± 2.52 | 0.18 ± 2.59 | 0.02 (0.8, –0.9) | 0.34 ± 2.45 | –0.01 ± 2.57 | –0.35 (0.9, –0.2) | 0.984; 0.000 | 0.347; 0.099 | 0.507; 0.050 |
Repeated sprint protocol performance, gas exchange, and perception after low carbohydrate high fat (LCHF) and high carbohydrate low fat (HCLF) treatments. LCHF lowered mean carbohydrate and respiratory exchange ratio, and lowered mean fat oxidation but remained unchanged pre to post-HCLF. Both LCHF and HCLF lowered session affect. n = 10. Mean ± SD. Total time = time to complete all sprints; RPE-O = RPE for overall body; RPE = rating of perceived exertion (OMNI rating of exertion); RER = Respiratory exchange ratio; VO2 = oxygen consumption; VCO2 = carbon dioxide production; VE = ventilation; RR = Respiratory Rate; LCHF = low carbohydrate high fat diet; HCLF = high carbohydrate low fat diet.
# = significant difference from Pre vs. Post (p ≤ 0.05).
* = significant difference between treatment (p ≤ 0.05); † = significant difference between LCHF and HCLF at Post (p ≤ 0.05). Bold values represent the p < 0.05.