Influence of exercise on visceral pain: an explorative study in healthy volunteers

Figures & data

Figure 1 Timeline study procedures.

Notes: Interventions consisted of aerobic cycling, isometric knee extension and deep breathing as active control condition, followed by the pain measures and 30 minutes of rest. The numbers indicate the time in minutes. ^(a)This block was repeated twice.
Abbreviations: CPM, conditioned pain modulation; HR, heart rate; Borg, Borg’s Rate of Perceived Exertion scale.

Figure 2 Locations pressure algometry.

Note: Pressure algometry locations, including the trapezius muscle (location 1), T10 dermatome (location 2), thenar muscle (location 3), rectus femoris muscle (location 4) and adductor halluces muscle (location 5).

Table 1 Baseline characteristics of the healthy volunteers (n=15)

Characteristics	Mean (SD)
Age, years	25 (6.5)
Gender, M:F	9:6
Height, m	1.79 (0.08)
Weight, kg	73 (9.7)
Body mass index, kg/m^2	22.6 (2.0)
STAI Y1 scorea	27.67 (5.5)
STAI Y2 scorea	31.20 (9.7)
MOS SF-36 PCS	54.02 (3.4)
MOS SF-36 MCS	51.93 (5.0)

Note:

a Y1: state, score at this moment; Y2: trait, score in general.

Abbreviations: M, male; F, female; STAI, State-Trait Anxiety Inventory; MOS SF-36, Medical Outcome Short-Form 36; PCS, physical component summary; MCS, mental component summary.

Table 2 Outcomes of the pain measurement at baseline and after aerobic cycling exercise, isometric knee extension and the control condition

Pain test	Baseline, mean (SD)	Aerobic cycling, mean (SD)	Isometric extension, mean (SD)	Control condition, mean (SD)
Visceral stimulation (mA)
VAS 1	9.1 (3.6)	9.2 (4.6)	7.8 (2.9)	7.9 (4.6)
VAS 3	11.7 (3.4)	13.4 (6.5)	11.3 (3.5)	11.4 (4.6)
VAS 5	17.9 (7.1)	18.6 (8.2)	17.1 (6.0)	16.0 (5.2)
VAS 7	22.0 (8.4)	22.2 (8.7)	20.8 (7.2)	19.8 (4.8)
Pressure algometry (kPa)
Trapezius muscle	491 (118)	461 (143)	426 (111)	433 (184)
T10 dermatome	549 (142)	509 (124)	496 (114)	528 (145)
Thenar muscle	493 (116)	462 (77)	445 (85)	445 (100)
Rectus femoris muscle	641 (179)	669 (154)	671 (185)	598 (134)
Adductor halluces muscle	552 (141)	515 (98)	559 (115)	548 (157)
CPM
PPT before (kPa)	677 (148)	688 (161)	679 (137)	619 (139)
PPT after (kPa)	724 (154)	756 (198)	777 (145)	775 (227)
VAS 30 seconds	4.6 (1.7)	4.9 (2.4)	5.1 (2.1)	5.2 (1.9)
VAS 60 seconds	6.5 (1.6)	6.3 (2.1)	6.4 (1.6)	6.8 (1.5)
VAS 90 seconds	7.5 (1.4)	7.1 (1.5)	7.4 (1.4)	7.5 (1.3)
VAS 120 seconds	7.9 (1.2)	7.7 (1.4)	8.0 (1.3)	8.1 (1.2)
VAS overall	6.9 (1.2)	6.9 (1.6)	7.1 (1.5)	7.3 (1.4)

Notes: PPT before: pressure pain threshold before cold pressor test, PPT after: pressure pain threshold after cold pressor test and VAS overall: mean VAS scores during the immersion.

Abbreviations: SD, standard deviation; VAS, visual analogue scale; CPM, conditioned pain modulation.

Figure 3 Visceral stimulation.

Note: Baseline-corrected mean intensities (mA) where participants rated 1, 3, 5 and 7 on the visual analogue scale (VAS) after aerobic cycling, isometric knee extension and the control condition.

Figure 4 Pressure algometry.

Note: Baseline-corrected mean pressure pain thresholds at the trapezius muscle (location 1), T10 dermatome (location 2), thenar muscle (location 3), rectus femoris muscle (location 4) and adductor halluces muscle (location 5) after aerobic cycling, isometric knee extension and the control condition.

Figure 5 Conditioned pain modulation.

Note: Baseline-corrected pressure pain thresholds (PPT) before and after the cold pressor test after aerobic cycling, isometric extension and the control condition.

Table 3 Heart rate (HR) during aerobic cycling, isometric extension and the control condition

HR	Aerobic cycling, mean (SD)	Isometric extension, mean (SD)	Control condition, mean (SD)
Resta	63 (7.2)	76 (13.4)	69 (7.9)
Endb	162* (9.6)	86 (11.3)	64 (7.6)
Meanc	164* (5.7)	87 (11.4)	66 (7.6)

Notes:

a HR rest was measured before the interventions.

b HR end was measured at the end of aerobic cycling and isometric knee extension. In the control condition, “HR end” was the minimum HR in every round of deep breathing.

c HR mean was the mean heart rate over the complete intervention.

* Significant increase; p<0.001.

Figure 6 Heart rate during deep breathing.

Notes: Mean absolute difference between start heart rate (HR) and minimum HR in every round of deep breathing in the control condition. Data are presented for each participant individually.
Abbreviation: bpm, beats per minute.