Table 2

Lower maximal oxygen uptake and endurance performance in myositis patients compared to healthy controls.

Patients n = 23

Mean ± SD

Healthy Controls

n = 12

Mean ± SD

Unpaired t-test


VO2 max test


VO2 max (l min-1)

1.65 ± 0.51

2.28 ± 0.55

P <0.01

VO2, max/body weight (ml min-1 kg-1)

22 ± 5

32 ± 6

P <0.01

Power at VO2 max (W)

120 ± 36

185 ± 38

P <0.001

Respiratory exchange ratio(RQ = CO2/O2)

1.1 ± 0.1

1.2 ± 0.1

n.s.

Maximum heart rate (min-1)

160 ± 15

173 ± 16

n.s.

Borg rating (6 to 20):

   Peripheral exertion

19 ± 1

19 ± 1

n.s

   Central exertion

17 ± 3

18 ± 2

n.s.


Endurance cycling test


Time to exhaustion (minute)

14.0 ± 5.1

26.1 ± 11.3

P <0.001

Lactate (mM)

10.6 ± 3.6

11.7 ± 3.7

n.s.

Percentage maximum heart rate

91 ± 1

96 ± 1

n.s.

Borg rating (6 to 20):

   Peripheral exertion

19 ± 1

18 ± 2

n.s

   Central exertion

17 ± 1

18 ± 2

n.s


n.s., Non-significant; VO2 max, maximal oxygen uptake; endurance cycling test, time cycling to exhaustion performed with a constant power, which in each individual was set to requiring 65% of baseline VO2 max; Borg rating, rating of exertion at end of VO2 max test and at the end of the endurance cycling test; Lactate, concentration of lactate measured in muscle vastus lateralis with microdialysis directly after the endurance cycling test.

Alemo Munters et al. Arthritis Research & Therapy 2013 15:R83   doi:10.1186/ar4263

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