Table 1.

Descriptive characteristics of studies included in the analysis

	Study characteristics
Study	N	Gender	Age	Type	Level	Time of day	Collection time
Alix-Sy et al 49	18	m	24.6	T	NAT	PM	90
Balthazar et al 48	8	m	27.8	I	NAT	AM	0
Bateup et al 33	17	f	20	T	NAT	PM	15
Booth et al 50	6	m	19	I	NAT	PM	15
Carré et al 29	14	m	18.2	T	NAT	PM	45
Coelho et al 51	17	m	23.6	I	INT	PM	30
Harris et al 52	8	m	35.1	I	REG	AM	0
Cunniffe et al 30	15	m	26.2	T	INT	PM	90
Díaz et al 53	11	m	21.5	I	NAT	PM	120
Doan et al 47	8	m	20.3	I	NAT	AM	45
Edwards et al 34
Team	15	f	–	T	REG	PM	95
Individual	13	f	–	I	NAT	PM	10
Elloumi et al 54	20	m	25.8	T	INT	PM	180
Filaire et al 55	12	f	12.5	I	NAT	PM	5
Filaire et al 31	18	m	22.2	I	REG	PM	5
Haneishi et al 56	10	f	20.2	T	NAT	PM	30
Iellamo et al 41
Male	4	m	26.7	I	NAT	AM	0
Female	4	f	26.7	I	NAT	AM	0
McKay et al 57	15	m	22.5	I	NAT	–	20
McLellan et al 58	17	m	24.2	T	NAT	PM	30
Moreira et al 59	12	m	19	T	NAT	PM	30
Oliveira et al 60	23	f	24.2	T	NAT	PM	30
Piacentini et al 61	5	m	47	I	NAT	AM	0
Robazza et al 62	9	m	29.1	T	NAT	PM	0
Salvador et al 63	17	m	19.4	I	REG	AM	40
Sperlich et al 64	17	m	22	I	NAT	–	2
Yuan et al 65	16	mix	15.4	I	REG	AM	45

n, number of participants in the study. Gender: f, female athletes; m, male athletes; mix, mixed gender population. Type: I, individual sport; T, team sport. Level: INT, International; NAT, National; REG, Regional. Time of day: AM=Morning, PM=Afternoon. Collection time: Saliva collection time in minutes before start of the competition. Dashes indicate that data were not available.