Table 4.

Summary statistics showing treatment effects (mean and SD) on measures derived from the NASA-TLX

		Baseline		Post-treatment		Change from baseline
		Mean	SD	Mean	SD	Mean	SD
Mental demand	Placebo	61	21	60	24	−1	16
	25 g glucose	63	18	58	24	−4	19
	60 g glucose	53	23	53	25	−1	21
	Caffeine–glucose	59	17	58	18	0	15
Physical demand	Placebo	28	21	32	26	4	16
	25 g glucose	29	22	27	20	−2	13
	60 g glucose	29	25	33	26	5	12
	Caffeine–glucose	24	18	31	22	8	18
Temporal demand	Placebo	65	20	62	25	−3	22
	25 g glucose	63	19	61	24	−2	18
	60 g glucose	60	17	55	22	−5	19
	Caffeine–glucose	60	18	55	21	−5	15
Performance	Placebo	34	17	32	16	−3	19
	25 g glucose	41	17	37	21	−4	20
	60 g glucose	44	22	40	22	−4	20
	Caffeine–glucose	35	20	33	22	−2	23
Effort	Placebo	68	18	65	19	−2	11
	25 g glucose	66	17	63	24	−3	14
	60 g glucose	64	21	62	20	−2	18
	Caffeine–glucose	62	18	56	21	−7	17
Frustration	Placebo	42	24	42	22	0	22
	25 g glucose	36	23	36	24	0	16
	60 g glucose	42	22	40	23	−2	22
	Caffeine–glucose	36	26	37	23	1	20