Limits...
Skeletal muscle properties and fatigue resistance in relation to smoking history.

Wüst RC, Morse CI, de Haan A, Rittweger J, Jones DA, Degens H - Eur. J. Appl. Physiol. (2008)

Bottom Line: Maximal strength and isometric contractile speed did not differ significantly between smokers and non-smokers.Muscle fatigue (measured as torque decline during a series of repetitive contractions) was greater in smokers (P = 0.014), but did not correlate with cigarette pack years (r = 0.094, P = 0.615), cigarettes smoked per day (r = 10.092, P = 0.628), respiratory function (%FEV(1pred)) (r = -0.187, P = 0.416), or physical activity level (r = -0.029, P = 0.877).An acute and reversible effect of smoking could be caused by carbon monoxide and/or other substances in smoke hampering oxygen delivery and mitochondrial function.

View Article: PubMed Central - PubMed

Affiliation: Institute for Biomedical Research into Human Movement and Health (IRM), Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, UK. r.wust@mmu.ac.uk

ABSTRACT
Although smoking-related diseases, such as chronic obstructive pulmonary disease (COPD), are often accompanied by increased peripheral muscle fatigability, the extent to which this is a feature of the disease or a direct effect of smoking per se is not known. Skeletal muscle function was investigated in terms of maximal voluntary isometric torque, activation, contractile properties and fatigability, using electrically evoked contractions of the quadriceps muscle of 40 smokers [19 men and 21 women; mean (SD) cigarette pack years: 9.9 (10.7)] and age- and physical activity level matched non-smokers (22 men and 23 women). Maximal strength and isometric contractile speed did not differ significantly between smokers and non-smokers. Muscle fatigue (measured as torque decline during a series of repetitive contractions) was greater in smokers (P = 0.014), but did not correlate with cigarette pack years (r = 0.094, P = 0.615), cigarettes smoked per day (r = 10.092, P = 0.628), respiratory function (%FEV(1pred)) (r = -0.187, P = 0.416), or physical activity level (r = -0.029, P = 0.877). While muscle mass and contractile properties are similar in smokers and non-smokers, smokers do suffer from greater peripheral muscle fatigue. The observation that the cigarette smoking history did not correlate with fatigability suggests that the effect is either acute and/or reaches a ceiling, rather than being cumulative. An acute and reversible effect of smoking could be caused by carbon monoxide and/or other substances in smoke hampering oxygen delivery and mitochondrial function.

Show MeSH

Related in: MedlinePlus

Torque, expressed as percentage of initial value, during the fatigue protocol is plotted every 2 s during the fatigue protocol for male (a) and female (b) smokers and non-smokers. Women had a significantly higher fatigue resistance (P < 0.001). Both male and female smokers fatigued more than the non-smokers (P = 0.014)
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2480601&req=5

Fig3: Torque, expressed as percentage of initial value, during the fatigue protocol is plotted every 2 s during the fatigue protocol for male (a) and female (b) smokers and non-smokers. Women had a significantly higher fatigue resistance (P < 0.001). Both male and female smokers fatigued more than the non-smokers (P = 0.014)

Mentions: Figure 2a and b show a typical example of the fatigue test (Fig. 2a), and an example of the reduction in torque and rate of relaxation from the first to the last contraction (Fig. 2b). In all groups there was a progressive decline in torque (Fig. 3) and MRR, the latter indicating a slowing of the muscle (Fig. 4). Women were more fatigue resistant than men (P < 0.001), both in terms of torque and MRR. In both men and women, the fatigue resistance was lower in smokers than non-smokers (P = 0.014) (Fig. 3). The absence of a smoke × sex interaction indicates that the effect of smoking was similar in both sexes.Fig. 2


Skeletal muscle properties and fatigue resistance in relation to smoking history.

Wüst RC, Morse CI, de Haan A, Rittweger J, Jones DA, Degens H - Eur. J. Appl. Physiol. (2008)

Torque, expressed as percentage of initial value, during the fatigue protocol is plotted every 2 s during the fatigue protocol for male (a) and female (b) smokers and non-smokers. Women had a significantly higher fatigue resistance (P < 0.001). Both male and female smokers fatigued more than the non-smokers (P = 0.014)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2480601&req=5

Fig3: Torque, expressed as percentage of initial value, during the fatigue protocol is plotted every 2 s during the fatigue protocol for male (a) and female (b) smokers and non-smokers. Women had a significantly higher fatigue resistance (P < 0.001). Both male and female smokers fatigued more than the non-smokers (P = 0.014)
Mentions: Figure 2a and b show a typical example of the fatigue test (Fig. 2a), and an example of the reduction in torque and rate of relaxation from the first to the last contraction (Fig. 2b). In all groups there was a progressive decline in torque (Fig. 3) and MRR, the latter indicating a slowing of the muscle (Fig. 4). Women were more fatigue resistant than men (P < 0.001), both in terms of torque and MRR. In both men and women, the fatigue resistance was lower in smokers than non-smokers (P = 0.014) (Fig. 3). The absence of a smoke × sex interaction indicates that the effect of smoking was similar in both sexes.Fig. 2

Bottom Line: Maximal strength and isometric contractile speed did not differ significantly between smokers and non-smokers.Muscle fatigue (measured as torque decline during a series of repetitive contractions) was greater in smokers (P = 0.014), but did not correlate with cigarette pack years (r = 0.094, P = 0.615), cigarettes smoked per day (r = 10.092, P = 0.628), respiratory function (%FEV(1pred)) (r = -0.187, P = 0.416), or physical activity level (r = -0.029, P = 0.877).An acute and reversible effect of smoking could be caused by carbon monoxide and/or other substances in smoke hampering oxygen delivery and mitochondrial function.

View Article: PubMed Central - PubMed

Affiliation: Institute for Biomedical Research into Human Movement and Health (IRM), Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, UK. r.wust@mmu.ac.uk

ABSTRACT
Although smoking-related diseases, such as chronic obstructive pulmonary disease (COPD), are often accompanied by increased peripheral muscle fatigability, the extent to which this is a feature of the disease or a direct effect of smoking per se is not known. Skeletal muscle function was investigated in terms of maximal voluntary isometric torque, activation, contractile properties and fatigability, using electrically evoked contractions of the quadriceps muscle of 40 smokers [19 men and 21 women; mean (SD) cigarette pack years: 9.9 (10.7)] and age- and physical activity level matched non-smokers (22 men and 23 women). Maximal strength and isometric contractile speed did not differ significantly between smokers and non-smokers. Muscle fatigue (measured as torque decline during a series of repetitive contractions) was greater in smokers (P = 0.014), but did not correlate with cigarette pack years (r = 0.094, P = 0.615), cigarettes smoked per day (r = 10.092, P = 0.628), respiratory function (%FEV(1pred)) (r = -0.187, P = 0.416), or physical activity level (r = -0.029, P = 0.877). While muscle mass and contractile properties are similar in smokers and non-smokers, smokers do suffer from greater peripheral muscle fatigue. The observation that the cigarette smoking history did not correlate with fatigability suggests that the effect is either acute and/or reaches a ceiling, rather than being cumulative. An acute and reversible effect of smoking could be caused by carbon monoxide and/or other substances in smoke hampering oxygen delivery and mitochondrial function.

Show MeSH
Related in: MedlinePlus