Effects of branched chain amino acids, l-citrulline, and alpha-glycerylphosphorylcholine supplementation on exercise performance in trained cyclists: a randomized crossover trial

Figures & data

Table 1. Supplement and placebo formulation.

Supplement		Placebo
Ingredient Description	Amount (g)	Ingredient Description	Amount (g)
BCAAs (2:1:1)^1	8.4^2	Maltodextrin	14.952
L-Citrulline	6.2^2
A-GPC	0.312^2
Lemon Lime flavor	1.2	Lemon Lime flavor	1.2
Steviol Glycosides	0.5	Steviol Glycosides	0.5
Citric Acid	2.0	Citric Acid	2.0
Potassium Citrate	0.207	Potassium Citrate	0.207
Sea Salt	0.582	Sea Salt	0.582
Thiamin (Vitamin B1) (100%DV)	0.0018	Thiamin (Vitamin B1) (100%DV)	0.0018
Riboflavin (Vitamin B2) (25%DV)	0.0005	Riboflavin (Vitamin B2) (25%DV)	0.0005
Niacinamide (Vitamin B3) (100%DV)	0.0245	Niacinamide (Vitamin B3) (100%DV)	0.0245
D-Calcium Pantothenate (Vitamin B5) (100%DV)	0.011	D-Calcium Pantothenate (Vitamin B5) (100%DV)	0.011
Pyridoxine Hydrochloride (Vitamin B6) (200% DV)	0.0041	Pyridoxine Hydrochloride (Vitamin B6) (200% DV)	0.0041
Biotin (Vitamin B7) (100%DV)	0.0054	Biotin (Vitamin B7) (100%DV)	0.0054
Folic Acid (Vitamin B9) (50%DV)	0.0017	Folic Acid (Vitamin B9) (50%DV)	0.0017
Cyanocobalamin (Vitamin B12) (500%DV)	0.0024	Cyanocobalamin (Vitamin B12) (500%DV)	0.0024
Bitterness masker	1.2
Total	20.69^3	Total	19.49^3

1.2:1:1 ratio of leucine, isoleucine, valine

2.Overage included to ensure target amounts were met.

3.Negligible difference in total weights due to absence of bitterness masker in the placebo.

Table 2. Average OMNI-Cycle scale perceived exertion (mean ± SD).

Treatment	Distance
	5 km	10 km	15 km	20 km
Supplement	6.39 ± 1.59	7.76 ± 1.07	8.38 ± 1.02	9.47 ± 0.69
Placebo	6.52 ± 1.17	7.55 ± 1.08	8.35 ± 0.69	9.47 ± 0.63

Table 3. 20 km time trial test VAS results.

VAS Measurement	Supplement Mean (± SD)	Placebo Mean (± SD)	p-value
Muscular fatigue	71.8 (±20.6)	64.0 (±21.0)	0.076
Muscular soreness	50.0 (±32.4)	42.2 (±27.6)	0.049*
Overall energy	60.7 (±23.6)	55.6 (±25.9)	0.447
Ease of pedaling	53.7 (±26.6)	53.2 (±25.2)	0.920
Mental focus/concentration	41.0 (±27.0)	28.0 (±26.0)	0.030*

* Indicates p-value <.05 (two-tailed).

Table 4. High intensity endurance cycling test VAS results.

VAS Measurement	Supplement Mean (± SD)	Placebo Mean (± SD)	p-value
Muscular fatigue	79.1 (±25.6)	81.4 (±18.5)	.275
Muscular soreness	65.6 (±29.9)	57.0 (±28.7)	.026*
Overall energy	65.6 (±23.5)	65.8 (±24.7)	.483
Ease of pedaling	73.1 (±24.8)	75.6 (±20.2)	.204
Mental focus/concentration	48.0 (±29.5)	51.0 (±34.0)	.328

* Indicates p-value <.05 (two-tailed).

Figure 1. Time trial peak power versus time trial average power.

Figure 2. Time trial average power versus time trial time to completion.

Figure 3. Time trial peak power versus time trial time to completion.

Figure 4. VO₂ max versus time trial average power.

Figure 5. VO₂ max versus time trial time to completion.

Table 5. Correlations between cycling test variables – supplement trial.

	1	2	3	4	5
1. TT Average Power	1.00
2. TT Peak Power	.531**	1.00
3. TT Time to Completion	−.979***	−.499**	1.00
4. HIEC Time to Fatigue	.157	−.066	−.228	1.00
5. VO2 Max	.496**	.299	−.535**	−.210	1.00

** Indicates p-value <.005 (two-tailed); *** Indicates p-value <.001 (two-tailed).

Table 6. Correlations between cycling test variables – placebo trial.

	1	2	3	4	5
1. TT Average Power	1.00
2. TT Peak Power	.654***	1.00
3. TT Time to Completion	−.988***	−.613***	1.00
4. HIEC Time to Fatigue	−.008	−.274	−.054	1.00
5. VO2 Max	.577***	.324	−.583***	−.107	1.00

** Indicates p-value <.005 (two-tailed); *** Indicates p-value <.001 (two-tailed).

Data availability statement

The datasets used and/or analyzed during the present study are available from the corresponding author on reasonable request.