Table 3.

Within- and between-group differences from baseline to 6 months by randomization group.

		Within-group estimated mean change (95% CI)				Between-group differences (95% CI)
Outcomesa		HIIT (n = 65)	p Value	MCT (n = 63)	p Value	6 months (n = 128)	p Value
Cognition, z score
GCF
	Unadjusted	−0.02 (−0.12 to 0.08)	0.67	0.06 (−0.04 to 0.16)	0.23	−0.08 (−0.22 to 0.06)	0.25
	Adjusted	−0.03 (−0.14 to 0.08)	0.64	0.04 (−0.07 to 0.14)	0.48	−0.06 (−0.21 to 0.08)	0.38
Memory
	Unadjusted	−0.02 (−0.18 to 0.14)	0.83	0.12 (−0.03 to 0.28)	0.11	−0.14 (−0.36 to 0.08)	0.20
	Adjusted	−0.004 (−0.17 to 0.16)	0.96	0.11 (−0.05 to 0.27)	0.19	−0.11 (−0.34 to 0.11)	0.31
Concentration
	Unadjusted	−0.10 (−0.29 to 0.08)	0.28	0.08 (−0.10 to 0.25)	0.40	−0.18 (−0.43 to 0.08)	0.18
	Adjusted	−0.14 (−0.33 to 0.06)	0.18	0.05 (−0.15 to 0.24)	0.63	−0.18 (−0.45 to 0.08)	0.17
Planning
	Unadjusted	0.02 (−0.21 to 0.25)	0.89	−0.04 (−0.26 to 0.18)	0.69	0.06 (−0.26 to 0.38)	0.71
	Adjusted	−0.04 (−0.28 to 0.21)	0.77	−0.04 (−0.28 to 0.20)	0.75	0.002 (−0.33 to 0.33)	0.99
Reasoning
	Unadjusted	0.06 (−0.16 to 0.27)	0.60	0.14 (−0.06 to 0.35)	0.18	−0.08 (−0.38 to 0.21)	0.57
	Adjusted	0.05 (−0.18 to 0.27)	0.68	0.10 (−0.12 to 0.32)	0.39	−0.05 (−0.35 to 0.26)	0.76
Blood pressure
Systolic, mmHg
	Unadjusted	−2.58 (−6.62 to 1.46)	0.21	1.16 (−2.76 to 5.07)	0.56	−3.74 (−9.36 to 1.89)	0.19
	Adjusted	−0.24 (−4.52 to 4.04)	0.91	2.86 (−1.32 to 7.06)	0.18	−3.11 (−8.84 to 2.62)	0.28
Diastolic, mmHg
	Unadjusted	−2.64 (−4.79 to –0.48)	0.017	−0.53 (−2.63 to 1.56)	0.62	−2.11 (−5.11 to 0.90)	0.17
	Adjusted	−2.41 (−4.69 to –0.12)	0.039	−0.47 (−2.71 to 1.78)	0.68	−1.94 (−5.01 to 1.13)	0.21
Resting heart rate, bpm
	Unadjusted	−1.76 (−4.81 to 1.29)	0.26	0.54 (−2.40 to 3.48)	0.72	−2.3 (−6.53 to 1.94)	0.28
	Adjusted	−1.35 (−4.48 to 1.77)	0.39	1.19 (-1.86 to 4.24)	0.44	−2.54 (−6.72 to 1.64)	0.23
Trail-Making Testb
Part A
	Unadjusted	−0.07 (−0.11 to −0.03)	<0.001	−0.07 (−0.10 to −0.03)	0.001	−0.005 (−0.06 to 0.05)	0.86
	Adjusted	−0.06 (−0.10 to −0.02)	<0.003	−0.07 (−0.11 to −0.03)	<0.001	0.01 (−0.04 to 0.07)	0.69
Part B
	Unadjusted	−0.07 (−0.11 to −0.03)	0.001	−0.06 (−0.09 to −0.02)	0.002	−0.01 (−0.06 to 0.04)	0.68
	Adjusted	−0.06 (−0.10 to −0.01)	<0.009	−0.05 (−0.09 to −0.005)	0.029	−0.01 (−0.7 to 0.04)	0.69
B minus A
	Unadjusted	−0.002 (−0.05 to 0.05)	0.93	0.001 (−0.05 to 0.05)	0.97	−0.003 (−0.07 to 0.07)	0.93
	Adjusted	0.01 (−0.04 to 0.07)	0.64	0.03 (−0.03 to 0.08)	0.31	−0.01 (−0.09 to 0.06)	0.69
Cardiorespiratory fitnessc
Time to exhaustion, min
	Unadjusted	1.12 (0.63 to 1.62)	<0.001	0.93 (0.45 to 1.42)	<0.001	0.19 (−0.51 to 0.88)	0.59
	Adjusted	1.14 (0.64 to 1.63)	<0.001	0.95 (0.46 to 1.44)	<0.001	0.19 (−0.51 to 0.88)	0.59
Intensity, METs
	Unadjusted	1.18 (0.58 to 1.78)	<0.001	0.83 (0.24 to 1.43)	0.007	0.35 (−0.50 to 1.20)	0.42
	Adjusted	1.14 (0.54 to 1.74)	<0.001	0.83 (0.24 to 1.42)	0.006	0.31 (−0.53 to 1.15)	0.47
Maximum heart rate, bpm
	Unadjusted	−0.24 (−4.91 to 4.42)	0.92	0.65 (−3.95 to 5.25)	0.78	−0.89 (−7.44 to 5.66)	0.79
	Adjusted	−0.29 (−4.95 to 4.36)	0.90	0.64 (−3.96 to 5.24)	0.78	−0.93 (−7.48 o 5.61)	0.78

^aCalculated from linear mixed effects regression models that included group (HIIT or MCT), time (baseline and 6 months), and group × time interaction terms. Results are presented as intention-to-treat approach. Bold numbers indicate significant differences. Adjusted models account for the influence of age, sex, Montreal Cognitive Assessment score, baseline cardiorespiratory fitness, as well as history or medication use for diabetes, cardiovascular disease, and depression.

^bLog10 transformation applied.

^cData available from 118 (HIIT = 62, MCT = 56). CI, confidence interval; HIIT, high-intensity interval training; MCT, moderate-intensity continuous training, GCF, global cognitive functioning; METs, metabolic equivalent.