Replacing sitting with light-intensity physical activity throughout the day versus 1 bout of vigorous-intensity exercise: similar cardiometabolic health effects in multiple sclerosis. A randomised cross-over study

Figures & data

Figure 1. Study design. After checking study eligibility and performing a maximal cardiopulmonary exercise test (CPET) during the screening visit, participants performed four 4-day activity regimens [CONTROL, SIT, LIPA (light-intensity physical activity), EX (exercise) regimen] in free-living conditions, followed by a test day to assess outcomes and a wash-out period of 10 days. Habitual physical activity levels were maintained during the CONTROL regimen and manipulated as indicated during the subsequent regimens. The order of the SIT and LIPA regimen was randomised.

Visual representation of the study design in five subsequent blocks, with a first block showing the measurements during the screening visit (checking study eligibility and a cardiopulmonary exercise test), and four blocks showing the order of the four regimens (CONTROL first, EX last and SIT and LIPA randomised as second or third regimen) and the imposed protocol of physical activity and sedentary behaviour within each regimen.

Figure 2. Flow chart of study participants.

Flow chart of blocks connected to each other, showing the number of participants who started with the study at the top of the chart (36 persons were assessed for eligibility, from who 28 were included), and the number of participants who completed the study at the bottom the chart (27 completed the CONTROL regimen, 25 the SIT regimen, 24 the LIPA regimen and 21 the EX regime).

Table 1. Subject characteristics (n: 28).

Gender (female, %)	22, 78.6
Age (y)	45.4 ± 11.0
Height (cm)	168.0 ± 8.7
Weight (kg)	70.5 ± 13.6
BMI (kg/m²)	24.9 ± 3.8
EDSS score (0–5)	2.4 ± 1.2
MS duration (y)	11.3 ± 9.8
Wmax (watt)	142.5 ± 45.5
VO2peak (ml/min/kg)	28.5 ± 6.6
Criteria for max CPET
HR at VO2peak (% of age-predicted HRmax)*	96.4 ± 6.1
No. of pt. > 90% age-pred HRmax	23/25 (92%)
RER at VO2peak	1.17 ± 0.08
No. of pt. RER ≥ 1.10	24/27 (89%)
Lactate recovery (mmol/L)	9.4 ± 3.3
No. of pt. lactate recovery > 8.0 mmol/L	16/24 (67%)
RPE (6–20)	18.2 ± 1.4
No. of pt. RPE ≥ 17	28/28 (100%)
Medication intake (n)
Thyroid	8
Blood/heart	5
Lipid	3

y: years; BMI: body mass index; EDSS: expanded disability status scale; W_max: maximal workload; VO_2peak: maximal oxygen uptake; CPET: cardiopulmonary exercise test; No. of pt.: number of participants; RER: respiratory exchange ratio; RPE: rating of perceived exertion.

Data are expressed as means ± SD, *HRmax: 220-age.

Table 2. Physical activity during the activity regimens.

	CONTROL	SIT	LIPA	EXERCISE	p-Values
Sleeping time (h)	8.6 ± 0.8	8.9 ± 1.1	8.3 ± 1.0	8.8 ± 1.0	0.060
Sedentary time (h)	9.7 ± 1.9*	13.3 ± 1.6*	8.3 ± 1.8*	11.6 ± 1.7*	<0.001
Time in SB < 30 min (h)	4.7 ± 1.0	3.9 ± 1.5	4.6 ± 1.3	4.0 ± 1.3	0.024
Time in SB > 60 min (h)	2.6 ± 1.6^S,L	6.2 ± 2.5 ^C,L,E	1.6 ± 1.1 ^C,S,E	4.2 ± 2.2 ^S,L	<0.001
Standing time (h)	3.9 ± 1.4^S,E	1.2 ± 0.7 ^C,L,E	4.7 ± 1.4 ^S,E	1.7 ± 1.0 ^C,S,L	<0.001
Low I. walking time (h)	1.5 ± 0.7^S,E	0.5 ± 0.2 ^C,L	1.5 ± 0.5 ^S,E	0.7 ± 0.3 ^C,L	<0.001
Mod-vig. I. walking time (h)	0.1 ± 0.1^S,L,E	0.1 ± 0.1 ^C,L	1.2 ± 0.6 ^C,S,E	0.1 ± 0.2 ^C,L	<0.001
Cycling time (h)	0.1 ± 0.2^S,L,E	0.0 ± 0.1 ^C,E	0.0 ± 0.1 ^C,E	1.3 ± 0.3 ^C,S,L	<0.001
Steps (N)	7801 ± 3596^S,L,E	2420 ± 1418 ^C,L	13 983 ± 4251 ^C,S,E	3129 ± 1364 ^C,L	<0.001
Total EE/day (METs)—AP	34.0 ± 1.6^S,L,E	31.2 ± 0.7 ^C,L,E	36.2 ± 1.7 ^C,S	35.9 ± 1.6 ^C,S	<0.001
Total EE/day (METs)—VO2 PC	“*	“*	“*	37.8 ± 2.2*	<0.001

h: hour; SB: sitting bouts; I: intensity; mod-vig: moderate to vigourous; EE: energy expenditure; METs: metabolic equivalents; AP: activPAL estimation; VO₂ PC: VO₂-pulse coefficient estimation.

Data are expressed as means ± SD.

*Significantly different from all other regimens (p ≤ 0.05), ^CSignificantly different from CON (p ≤ 0.05), ^SSignificantly different from SIT (p ≤ 0.05), ^LSignificantly different from LIPA (p ≤ 0.05), ^ESignificantly different from EX (p ≤ 0.05). All analyses were Bonferroni corrected.

Figure 3. Two-hour oral glucose tolerance tests. (A,C) Average insulin and glucose levels per time point of the 2-h oral glucose tolerance test per activity regimen (

CONTROL,

SIT,

LIPA,

EX). (B,D) Total area under the curve (tAUC) for insulin and glucose concentrations shown in (A,C). Data are presented as estimated means ± SEM. LIPA: light-intensity physical activity; EX: exercise. ^#Trend towards significant difference (p = 0.054 at 45 min for SIT vs. LIPA, p = 0.063 at 60 min for SIT vs. EX). All analyses were Bonferroni corrected.

A four-section graphical representation of glucose and insulin concentrations during the 2-h oral glucose tolerance tests per activity regimen. The left panels are curves showing glucose and insulin levels per time point, the right panels are bars showing the total area under the curve for the left panels. Only the total area under the curve for insulin was significantly different between SIT and LIPA, and SIT and EX (p < 0.001).

Table 3. Cardiometabolic health outcomes.

	CONTROL	SIT	LIPA	EXERCISE	p-Values
Fasting insulin (pmol/L)	57.79 ± 5.60	64.32 ± 5.94	52.31 ± 4.93*	49.74 ± 4.84*	<0.001
2-h insulin (pmol/L)	350.21 ± 50.08	411.52 ± 41.76	329.23 ± 39.73	336.57 ± 46.22	0.073
Fasting glucose (mmol/L)	5.06 ± 0.12	4.94 ± 0.09	4.88 ± 0.09	4.72 ± 0.11	0.057
2-h glucose (mmol/L)	5.85 ± 0.39	5.93 ± 0.31	5.96 ± 0.30	6.33 ± 0.39	0.499
Matsuda-index	4.83 ± 0.59	4.21 ± 0.43	5.97 ± 0.59*	6.09 ± 0.61*	<0.001
MISI (mg/dl/min/µU/ml)	0.14 ± 0.02	0.10 ± 0.01	0.15 ± 0.02^#	0.13 ± 0.02	0.021
HIRI (mg/dl h × µU/ml h)	32.62 ± 2.50	34.92 ± 2.32	29.29 ± 2.06*	27.34 ± 2.51*	0.011
TG (mmol/L)	1.58 ± 0.32	1.61 ± 0.26	1.23 ± 0.22*^	1.08 ± 0.17*	<0.001
TC (mmol/L)	4.69 ± 0.21	4.82 ± 0.20	4.58 ± 0.20*	4.37 ± 0.19*	<0.001
HDL-C (mmol/L)	1.33 ± 0.08	1.30 ± 0.07	1.35 ± 0.08	1.33 ± 0.08	0.428
Non-HDL-C (mmol/L)	3.35 ± 0.23	3.51 ± 0.21	3.24 ± 0.22*	3.04 ± 0.20*	<0.001
LDL-C (mmol/L)	2.63 ± 0.17	2.76 ± 0.17	2.64 ± 0.18	2.49 ± 0.17	0.032
Apo A1	1.5 ± 0.1	1.4 ± 0.1	1.4 ± 0.1	1.4 ± 0.1	0.951
Apo B	0.88 ± 0.04	0.92 ± 0.05	0.86 ± 0.05*	0.86 ± 0.04	0.038
CRP	1.10 ± 0.22	1.30 ± 0.26	1.36 ± 0.26	1.83 ± 0.26*^	0.029
SBP (mm HG)	124 ± 3	126 ± 3	126 ± 4	125 ± 4	0.716
DBP (mm HG)	81 ± 2	82 ± 2	82 ± 2	78 ± 2*^	0.001
HRREST	65 ± 2	67 ± 2	64 ± 2*	63 ± 2	0.044
BW	70.9 ± 2.6	71.0 ± 2.6	70.9 ± 2.6	71.5 ± 2.6	0.062

LIPA: low-intensity physical activity; MISI: muscle insulin sensitivity index; HIRI: hepatic insulin resistance index; TG: triglycerides; TC: total cholesterol; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; Apo: apolipoprotein; CRP: c-reactive protein; SBP: systolic blood pressure; DBP: diastolic blood pressure; HRrest: resting heart rate; BW: body weight.

Data are expressed as estimated means ± SEM.

*Significantly different from SIT (p ≤ 0.05), ^Significantly different from LIPA (p ≤ 0.05), ^#Trend towards significant difference from SIT (p = 0.056). All analyses were Bonferroni corrected.