Table 1.

A summary of investigations examining the relationship between fitness and functional connectivity.

Author, year	Participant		Fitness assessment	Analysis Method	Results	Network(s) Implicated
	n, Subjects	Mean age (year)
Voss, 2010	32 YA and 120 OA	YA: 24.1±5.1 OA: 66.5±5.7	$\dot{\mathrm{V}}{\mathrm{O}}_{2\max }$	SBC (seed: PCC/rsp)	1) Link between ↑ FIT and ↑ FC between PCC and MFG 2) Link between the ↑ DMN and ↑ EF performance 3) ↑ FIT mediated the link between ↑ rsFC and ↑ EF performance	DMN
Boraxbekk, 2016	118 OA	61.5	BMI, WC, GS, resting SBP and DBP	ICA	Association between ↑ PA score and ↑ DMN rsFC	DMN
Voss, 2016	36 YA and 189 OA	YA: 22.1±3.0 OA: 65.1±4.4	$\dot{\mathrm{V}}{\mathrm{O}}_{2\max }$, PA/health history assessment	1) ICA 2) NBS 3) Target ROI selection	1) Link between ↑ FIT and ↑ DMN and DAN 2) No relationship between PA history and rsFC	1) DMN 2) DAN
Raichlen, 2016	11 ATH and 11 NATH YA	ATH: 21.5±2.4 NATH: 20.6±1.1	BMI, MET, $\dot{\mathrm{V}}{\mathrm{O}}_{2\max }$	SBC (seed: Bi APC, IPL, PCC, MPC, MC)	1) ↑ FPN and ↓ DMN in ATH > non-ATH 2) Dose-response relationship between PA and rsFC	1) FPN 2) DMN
Boyne, 2018	119 MAA	41±19	6MWT	1) SBC (seed: MLR, CLR) 2) Target ROI selection	1) Link between ↑ 6MWT distance and ↑ rsFC between MLR-R SFG and PC 2) Link between ↑ 6MWT distance and ↑ rsFC between the CLR and the M1F	SMN
Stillman, 2018	50 YA	25.2±5.1	$\dot{\mathrm{V}}{\mathrm{O}}_{2\max }$	SBC (seed: Bi anterior/posterior HIP)	1) Link between ↑ FIT and HIP rsFC 2) No significant relationship between FIT and caudate rsFC	HPN
Dorsman, 2020	212 OA	73.3±6.2	Self-reported PA	Within and between network analysis	Longitudinal association between ↑ PA and ↑ fronto-subcortical network	FPN

Notes: OA, older adults; YA, younger adults; MAA, middle-aged adults; ATH, athlete; NATH, non-athlete; $\dot{\mathrm{V}}{\mathrm{O}}_{2\max }$, maximal oxygen consumption; BMI, body mass index; WC, waist circumference; GS, grip strength; PA, physical activity; MET, metabolic equivalent of task; 6MWT, 6-min walk test; SBC, seed-based correlation analysis; PCC/rsp, posterior cingulate cortex/retrosplenial cortex; ICA, independent components analysis; NBS, network-based statistic; Bi, bilateral; APC, anterior prefrontal cortex; IPL, inferior parietal lobule; MPC, medial prefrontal cortex; MC, motor cortex; MLR, midbrain locomotor region; CLR, cerebellar locomotor region; HIP, hippocampus; FIT, fitness; MFG, medial frontal gyrus; DMN, default-mode network; EF, executive function; rsFC, functional connectivity; DAN, dorsal attention network; FPN, frontoparietal network; R, right; SFG, superior frontal gyrus; PC, paravermal cerebellum; M1F, primary motor cortex foot area; SMN, sensorimotor network; HPN, hippocampal network.