A Pre-Workout Supplement of Ketone Salts, Caffeine, and Amino Acids Improves High-Intensity Exercise Performance in Keto-Naïve and Keto-Adapted Individuals

Figures & data

Table 2. Nutrient content of the ketone-caffeine-amino acid supplement.

	Supplement	Chemical
Ingredient	Label	Analysis
Calories	41	74
Sodium (mg)	914	1080
Magnesium (mg)	245	188
Calcium (mg)	189	148
Caffeine (mg)	100	96.2
L-Leucine (mg)	NA	2100
L-Taurine (mg)	NA	2750
Total BHB (g)	7.2	–
R-BHB (%)	NA	72
S-BHB (%)	NA	28

NA = not available.

Figure 1. Schematic of the experimental testing session.

Figure 2. Individual time to exhaustion responses. Bars represent the difference in time to fatigue between the Ketone-Caffeine-Amino Acid (KCA) and Water trials. 10 of 12 Keto-Naïve and 11 of 12 Keto-Adapted participants cycled longer during the KCA trial. Trial (2) x Group (2) ANOVA indicated a significant (P < 0.001) effect of trial.

Table 3. Exercise performance responses.

	Keto-Adapted		Keto-Naïve		2 × 2 ANOVA		Trial
	KCA	Water	KCA	Water	Trial P	Group P	Cohen’s D
TTE (min:sec)	19:19 ± 6:57	17:48 ± 6:44*	20:46 ± 4:25	19:16 ± 4:20*	<0.001	0.551	1.00
Peak Power (W)	566 ± 114	578 ± 170	605 ± 66	609 ± 65	0.721	0.645	0.08
Average Power (W)	397 ± 24	394 ± 40	432 ± 45	414 ± 42	0.454	0.613	0.16
Peak VO2 (mL/kg/min)	41.8 ± 11.1	36.8 ± 12.0*	40.2 ± 5.8	39.5 ± 5.1	0.014	0.865	0.51
RER: Stage 1	0.95 ± 0.07	0.96 ± 0.06	0.94 ± 0.06	0.92 ± 0.06	0.890	0.219	0.06
Stage 2	0.96 ± 0.07	0.96 ± 0.06	1.01 ± 0.05	0.99 ± 0.04	0.725	0.009	0.12
Stage 3	0 .98 ± 0.06	0.99 ± 0.06	1.00 ± 0.03	0.99 ± 0.03	0.934	0.420	0.14
Stage 4	0 .96 ± 0.05	0.95 ± 0.02	1.00 ± .02	0.98 ± 0.02	0.080	0.001	0.31
RPE: Stage 1	12.1 ± 1.7	12.5 ± 1.6*	11.17 ± 1.53	11.50 ± 1.73	0.048	0.446
Stage 2	14.3 ± 2.1	14.9 ± 2.5	13.33 ± 2.42	13.75 ± 1.86	0.095	0.447
Stage 3	17.0 ± 2.5	16.8 ± 2.9	15.35 ± 2.45	16.17 ± 2.04	0.106	0.648
Stage 4	18.3 ± 2.3	18.8 ± 1.9	17.5 ± 1.78	18.83 ± 1.70	0.514	0.124

Bold values indicate P < 0.05.

Values are mean ± SD.

* P < 0.05 from corresponding KCA value.

Figure 3. Capillary blood R-beta-hydroxybutyrate (R-BHB) responses to ingestion of a Ketone-Caffeine-Amino Acid (KCA) supplement or Water in 12 Keto-Adapted (A) and 12 Keto-Naïve (B) subjects. Trial (2) x Time (11) ANOVA indicated time and time x trial interaction effects <0.000 for both groups. *P ≤ 0.05 from corresponding baseline value. #P ≤ 0.05 from corresponding Water time point. BL = baseline, MP = Exercise mid-point, IP = immediate post-exercise. Values are mean ± SE.

Figure 4. Plasma R-beta-hydroxybutyrate (R-BHB) and S-BHB responses to ingestion of a Ketone-Caffeine-Amino Acid (KCA) supplement or Water in 12 Keto-Adapted (A and C) and 12 Keto-Naïve (B and D) subjects. Trial (2) x Time (5) ANOVA indicated time and time x trial interaction effects <0.001 for all comparisons. *P ≤ 0.05 from corresponding baseline value. #P ≤ 0.05 from corresponding Water time point. BL = baseline, IP = immediate post-exercise. Values are mean ± SE.

Figure 5. Capillary blood glucose responses to ingestion of a Ketone-Caffeine-Amino Acid (KCA) supplement or Water in 12 Keto-Adapted (A) and 12 Keto-Naïve (B) subjects. Trial (2) x Time (11) ANOVA indicated a main effect of time (<0.001) for both groups. *P ≤ 0.05 from corresponding baseline value. BL = baseline, MP = Exercise mid-point, IP = immediate post-exercise. Values are mean ± SE.

Figure 6. Plasma lactate (A and D), glycerol (B and D), and insulin (C and E) responses to ingestion of a Ketone-Caffeine-Amino Acid (KCA) supplement or Water in 12 Keto-Adapted and 12 Keto-Naïve subjects. Trial (2) x Time (5) ANOVA indicated time effects <0.001 for lactate and glycerol. For lactate, there were significant interaction effects in Keto-Naïve (P = 0.040) and a trend in Keto-Adapted (0.086) subjects. For glycerol, there was a significant interaction effect in Keto-Naïve (P = 0.005) subjects. *P ≤ 0.05 from corresponding baseline value. #P ≤ 0.05 from corresponding Water time point. BL = baseline, IP = immediate post-exercise. Values are mean ± SE.

Table 1. Characteristics of groups at baseline.

	Keto-Adapted (n = 12)	Keto-Naïve (n = 12)
Sex (M/F)	9/3	8/4
Age (yr)	36.1 ± 7.5	22.9 ± 1.9*
Body mass (kg)	83.6 ± 9.7	79.3 ± 16.7
Height (cm)	176.9 ± 7.7	176.6 ± 13.0
VO2 peak (mL/kg/min)	40.0 ± 10.5	41.2 ± 5.1
HOMA-IR	0.48 ± 0.09	0.78 ± 0.64
Caffeinated Beverages (servings/wk)	2.6 ± 1.7	6.4 ± 9.4 ^a

Values are mean ± SD.

* P < 0.05 between groups.

a One participant consumed 35 caffeinated beverages/wk; excluding this outlier the mean was 3.8 ± 2.6.

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