Early absorption sources of caffeine can be a useful strategy for improving female table tennis players-specific performance

Figures & data

Table 1. The anthropometric data of participants.

Characteristic	Mean ± SD (n = 18)
Age (years)	20.50 ± 3.05
Height (cm)	165.16 ± 5.00
Weight (kg)	56.83 ± 6.50
BMI (kg/m^2)	20.83 ± 2.44

Figure 1. Cross-over and double-blind study design in three conditions.

Figure 2. The protocol of taking supplements and performing tests.

Figure 3. Service test on target.

Figure 4. Forehand drive test on target.

Table 2. The functional variables (mean ± standard deviation) measured in the three different experimental conditions.

Variables	PLA	CMR	CG
Agility (score)	23.22 ± 2.41	24.5 ± 1.85*	24.38 ± 2.19*
Hand speed (n)	12.19 ± 1.43	10.42 ± 1.30*	11.08 ± 1.27*^#
Coordination (n)	26.88 ± 2.21	28.88 ± 1.99*	28 ± 1.45
Explosive power of lower body muscles (w)	1698.55 ± 49.68	1935.38 ± 491.18*	1865.11 ± 452.00*
Explosive power of upper body muscles (cm)	438.66 ± 44.76	447.72 ± 46.46	448.33 ± 61.59
Speed of movement (s)	4.16 ± .40	3.54 ± 0.23*	3.74 ± 0.22*^#
Hand strength (kg)	53.05 ± 7.5	58.77 ± 5.01*	55.27 ± 8.30
Forehand drive (score)	15.72 ± 1.99	17.44 ± 2.5*	16.11 ± 2.58
Backhand Push (score)	28.30 ± .94	28.55 ± 0.99	28.05 ± 1.25
Serv (score)	36.33 ± 4.02	38.88 ± 3.59*	38.11 ± 4.82
Counter (n)	26.83 ± 1.33	26.94 ± 1.34	26.66 ± 1.87
Cognitive test (n)	2.11 ± 1.84	22.61 ± 1.53*	22.44 ± 1.5*

*: Significant difference compared to PLA(P < 0.05). #: Significant difference compared to CMR(P < 0.05).

Figure 5. Changes in agility, hand movement, speed of movement and coordination in three conditions of this study (PLA: placebo. CMR: caffeine mouth rinsing. CG: caffeine chewing gum). (a) agility test. (b) hand speed test. (c) speed of movement test. (d) coordination test. *: significant difference compared to PLA(P < 0.05). #: significant difference compared to CMR(P < 0.05).

Figure 6. Changes in the explosive power of lower body muscles, isometric handgrip strength, explosive power of upper body muscles and cognitive test in three conditions of this study (PLA: placebo. CMR: caffeine mouth rinsing. CG: caffeine chewing gum). (a) explosive power of lower body muscles. (b) isometric hand strength. (c) explosive power of upper body muscles. (d) cognitive test. *: significant difference compared to PLA(P < 0.05).

Figure 7. Changes in serve, forehand drive, backhand push and counter in three conditions of this study (PLA: placebo. CMR: caffeine mouth rinsing. CG: caffeine chewing gum). (a) serve test. (b) forehand drive test. (c) backhand push test. (d) counter test. PLA: placebo. CMR: caffeine mouth rinsing. CG: caffeine chewing gum. *: significant difference compared to PLA(P < 0.05).

Table 3. Pairwise comparisons in three conditions (PLA, CMR, CG).

Variables	Condition1	Condition2	Mean Difference	Sig	95% Cl
Agility	CMR	PLA	1.278*	0.037	0.067–2.488
		CG	0.111	1.000	-0.689 – -0.911
	CG	PLA	1.167*	0.002	0.415–1.911
Hand speed	CMR	PLA	-1.769*	0.000	-2.556 – -0.981
		CG	-0.666*	0.006	-1.149 – -0.182
	CG	PLA	-1.103*	0.000	-1.688 – -0.519
Coordination	CMR	PLA	2.000*	0.003	0.642–3.358
		CG	0.889	0.334	-0.517–2.295
	CG	PLA	1.111	0.091	-0.138–2.361
Explosive power of lower body muscles	CMR	PLA	236.833*	0.000	116.781–356.886
		CG	70.278	0.351	-42.679–183.234
	CG	PLA	166.556*	0.001	69.422–263.689
Explosive power of upper body muscles	CMR	PLA	9.056	0.198	-3.184–21.295
		CG	-0.611	1.000	-16.533–15.310
	CG	PLA	9.667	0.491	-7.965–27.299
Speed of movement	CMR	PLA	-0.614*	0.000	-0.899 – -0.329
		CG	-0.201*	0.012	-0.361 – -0.040
	CG	PLA	-0.413*	0.001	-0.656 – -0.171
Isometric hand strength	CMR	PLA	1.576	0.070	1.539–9.905
		CG	1.399	1.000	-0.213–7.213
	CG	PLA	1.292	0.089	-1.209–5.654
Serv	CMR	PLA	2.556*	0.005	0.744–4.367
		CG	0.778	0.939	-1.208–2.763
	CG	PLA	1.778	0.211	-0.665–4.221
Forehand drive	CMR	PLA	1.722*	0.003	0.570–2.874
		CG	1.333	0.071	-0.090–2.757
	CG	PLA	0.389	1.000	-0.919–1.697
Backhand Push	CMR	PLA	0.250	0.782	-0.320–0.820
		CG	0.500	0.554	-0.460–1.460
	CG	PLA	-0.250	1.000	-1.275–0.775
Counter	CMR	PLA	0.111	1.000	-0.629–0.851
		CG	0.278	1.000	-0.834–1.389
	CG	PLA	-0.167	1.000	-0.948–0.615
Cognitive test	CMR	PLA	2.500*	0.000	1.155 – -3.845
		CG	0.167	1.000	-0.699–1.032
	CG	PLA	2.333*	0.000	1.100–3.566

*The mean difference is significant at the .05 level. PLA: placebo. CMR: Caffeine mouth rinsing. CG: Caffeine chewing gum.

*: Significant difference compared to PLA(P < 0.05). #: Significant difference compared to CMR(P < 0.05).

PLA: placebo. CMR: Caffeine mouth rinsing. CG: Caffeine chewing gum.