TABLE 4.
One-mile time trial performance, gas exchange, and perception.
| Variable | LCHF | HCLF | P-value; η 2p | ||||||
| Pre Day –4 |
Post Day 28 |
Change Mean (95% CI) |
Pre Day –4 |
Post Day 28 |
Change Mean (95% CI) |
Treatment | Time | Interaction | |
| Time (sec) | 381.4 ± 30.6 | 367.1 ± 37.5# | −14.3 (26.4, 2.2) | 374.1 ± 38.6 | 374.0 ± 31.5# | –0.10 (11.1, –10.9) | 0.958; 0.000 | 0.009; 0.553 | 0.159; 0.208 |
| Mean Carbohydrate Oxidation (g/min) | 5.22 ± 1.07 | 4.16 ± 1.48† | −1.06 (1.8, 0.3) | 5.50 ± 2.14 | 5.91 ± 1.07 | 0.4 (0.7, –1.5) | 0.099; 0.273 | 0.335; 0.103 | 0.028; 0.433 |
| Mean Fat Oxidation (g/min) | 0.23 ± 0.29 | 0.67 ± 0.45#*† | 0.44 (−0.3, −0.6) | 0.21 ± 0.29 | 0.05 ± 0.11# | –0.15 (0.32, –0.01) | 0.023; 0.454 | 0.029; 0.427 | 0.001; 0.756 |
| Heart Rate (b.min-1) | 168.8 ± 8.7 | 173.4 ± 8.8#*† | 4.46 (−0.8, −8.2) | 167.7 ± 10.8 | 167.1 ± 11.1 | –0.59 (4.2, –2.9) | 0.003; 0.644 | 0.145; 0.220 | 0.040; 0.389 |
| Mean VO2 (ml/kg/min) | 50.2 ± 5.63 | 52.9 ± 6.84 | 2.72 (0.5, −5.9) | 48.4 ± 8.98 | 50.0 ± 6.19 | 1.67 (2.7, –6.0) | 0.070; 0.319 | 0.116; 0.252 | 0.651; 0.024 |
| Mean VO2 (L/min) | 4.23 ± 0.44 | 4.34 ± 0.66* | 0.11 (0.1, −0.3) | 4.03 ± 0.62 | 4.17 ± 0.62* | 0.14 (0.2, –0.5) | 0.013; 0.516 | 0.257; 0.140 | 0.869; 0.003 |
| Mean VCO2 (L/min) | 4.13 ± 0.46 | 3.97 ± 0.64 | −0.15 (0.4, −0.1) | 4.05 ± 0.82 | 4.24 ± 0.61 | 0.19 (0.3, –0.7) | 0.580; 0.035 | 0.904; 0.002 | 0.119; 0.249 |
| Mean VE (L/min) | 122.5 ± 13.4 | 123.6 ± 18.5 | 1.13 (6.1, −8.4) | 116.8 ± 16.9 | 123.4 ± 15.0 | 6.67 (7.3, –20.6) | 0.296; 0.120 | 0.332; 0.105 | 0.396; 0.081 |
| Mean RR (bpm) | 41.7 ± 6.47 | 43.9 ± 5.83 | 2.19 (−0.1, −4.3) | 42.0 ± 3.98 | 42.9 ± 6.52 | 0.93 (3.0, –4.9) | 0.712; 0.016 | 0.154; 0.212 | 0.534; 0.045 |
| Mean RER | 0.97 ± 0.05 | 0.91 ± 0.07*† | −0.06 (0.10, 0.01) | 1.00 ± 0.09 | 1.01 ± 0.05* | 0.01 (0.03, –0.06) | 0.045; 0.376 | 0.110; 0.259 | 0.021; 0.466 |
| Session RPE | 7.40 ± 1.64 | 7.90 ± 1.59 | 0.5 (0.3, −1.3) | 7.60 ± 1.42 | 7.70 ± 1.49 | 0.1 (0.8, –1.0) | 1.000; 0.000 | 0.081; 0.300 | 0.574; 0.036 |
| RPE-O | 6.70 ± 1.14 | 6.72 ± 1.02 | 0.02 (0.4, −0.5) | 6.64 ± 0.89 | 6.69 ± 1.09 | 0.05 (0.5, −0.6) | 0.871; 0.003 | 0.868; 0.003 | 0.897; 0.002 |
| Session affect | −0.10 ± 2.96 | −0.30 ± 2.98 | −0.2 (0.5, −0.1) | 0.00 ± 3.01 | −0.50 ± 2.87 | −0.50 (2.1, −1.1) | 0.935; 0.001 | 0.322; 0.109 | 0.703; 0.017 |
| Affect | 0.04 ± 2.16 | 0.51 ± 1.93# | 0.47 (0.15, −1.1) | 0.41 ± 1.73 | 0.79 ± 1.76# | 0.38 (0.2, −1.0) | 0.379; 0.087 | 0.017; 0.487 | 0.852; 0.004 |
One-mile time trial performance, gas exchange, and perception metrics were gathered pre and post-low carbohydrate high fat (LCHF) and high carbohydrate low fat treatments. n = 10. Mean ± SD. 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.