Creatine kinase isoforms following isometric exercise

Clarkson, Priscilla M.; Apple, Fred S.; Byrnes, William C.; McCormick, Kathleen; Triffletti, Philip

doi:10.1002/mus.880100108

Cited by 30 publications

(8 citation statements)

References 16 publications

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“…This can be assessed not only by the magnitude of decrease in MIF, which was more than double that reported in previous studies (e.g. Jones et al, 1989), but also by increases in indirect markers of muscle damage, such as creatine kinase and relaxed elbow angle, which were several-fold higher compared with other isometric exercise protocols (Clarkson et al, 1985(Clarkson et al, , 1986(Clarkson et al, , 1987Nosaka et al, 2002). This may have been due to the protocol used in the present study, which involved 50 maximal contractions of 10 s with 20 s rest between contractions, with the elbow flexors stretched to a lengthened position.…”

Section: Discussionmentioning

confidence: 89%

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Angle-specific impairment of elbow flexors strength after isometric exercise at long muscle length

Philippou

Maridaki

Bogdanis

2003

Journal of Sports Sciences

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In this study, we examined the long-term reductions in maximal isometric force (MIF) caused by a protocol of repeated maximal isometric contractions at long muscle length. Furthermore, we wished to ascertain whether the reductions in MIF are dependent on muscle length--that is, are the reductions in MIF more pronounced when the muscle contracts at a short length. The MIF of the elbow flexors of seven young male volunteers was measured at five different elbow angles between 50 degrees and 160 degrees. On a separate day, the participants performed 50 maximal voluntary isometric muscle contractions with the elbow flexors at a lengthened position; that is, with the shoulder hyperextended at 45 degrees and the elbow joint fixed at 140 degrees. Following this exercise, the MIF at the five elbow angles, range of motion, muscle soreness and plasma creatine kinase activity were measured at 24 h intervals for 4 days. On day 1, the decline in MIF was higher at the more acute elbow angles of 50 degrees (42 +/- 8%) and 70 degrees (39 +/- 8%; both P<0.01) than at 90 degrees (26 +/- 4%) and 140 degrees (16 +/- 3%; both P<0.01). No significant reduction in MIF was evident at an elbow angle of 160 degrees. Maximal isometric force at an elbow angle of 140 degrees was fully restored on day 3, whereas at an angle of 50 degrees it remained depressed for the 4 day observation period. Restoration of MIF was a function of the elbow angle, with force recovery being less at the smaller angles. The range of motion was decreased by 14 +/- 2 degrees on day 1 (P<0.01) and did not return to baseline values by day 4. Muscle soreness ratings remained significantly elevated for the 4 day period. Serum creatine kinase peaked on day 1 (522 +/- 129 IU, P<0.01) and decreased thereafter. We conclude that the disproportionate decrease in MIF at the small elbow angles and the length-specific recovery in MIF after repeated maximal isometric contractions at long muscle length may be explained by the presence of overstretched sarcomeres that increased in series compliance of the muscle, therefore causing a rightward shift of the force-length relationship.

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Section: Discussionmentioning

confidence: 89%

“…Each muscle action was performed for 10 s, with 20 s of intervening rest. A similar exercise regimen has previously been shown to result in an increase in serum creatine kinase activity, which is indirect evidence of muscle damage (Clarkson et al, 1985(Clarkson et al, , 1987.…”

Section: Isometric Exercise Protocolmentioning

confidence: 96%

Angle-specific impairment of elbow flexors strength after isometric exercise at long muscle length

Philippou

Maridaki

Bogdanis

2003

Journal of Sports Sciences

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“…For example, previous studies (3,5,19) reported little or no increases in CK, muscle soreness, and decrease in MVC after maximal voluntary isometric contractions of the knee extensors, reflecting little or no muscle damage after maximal voluntary isometric contractions. It is important to note that the voluntary isometric contractions performed in the present study were submaximal.…”

Section: Discussionmentioning

confidence: 99%

Comparison between voluntary and stimulated contractions of the quadriceps femoris for growth hormone response and muscle damage

Jubeau

Sartório

Marinone

et al. 2008

Journal of Applied Physiology

127

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NA.Comparison between voluntary and stimulated contractions of the quadriceps femoris for growth hormone response and muscle damage. J Appl Physiol 104: 75-81, 2008. First published November 1, 2007 doi:10.1152/japplphysiol.00335.2007.-This study aimed to compare voluntary and stimulated exercise for changes in muscle strength, growth hormone (GH), blood lactate, and markers of muscle damage. Nine healthy men had two leg press exercise bouts separated by 2 wk. In the first bout, the quadriceps muscles were stimulated by biphasic rectangular pulses (75 Hz, duration 400 s, on-off ratio 6.25-20 s) with current amplitude being consistently increased throughout 40 contractions at maximal tolerable level. In the second bout, 40 voluntary isometric contractions were performed at the same leg press force output as the first bout. Maximal voluntary isometric strength was measured before and after the bouts, and serum GH and blood lactate concentrations were measured before, during, and after exercise. Serum creatine kinase (CK) activity and muscle soreness were assessed before, immediately after, and 24, 48, and 72 h after exercise. Maximal voluntary strength decreased significantly (P Ͻ 0.05) after both bouts, but the magnitude of the decrease was significantly (P Ͻ 0.05) greater for the stimulated contractions (Ϫ22%) compared with the voluntary contractions (Ϫ9%). Increases in serum GH and lactate concentrations were significantly (P Ͻ 0.05) larger after the stimulation compared with the voluntary exercise. Increases in serum CK activity and muscle soreness were also significantly (P Ͻ 0.05) greater for the stimulation than voluntary exercise. It was concluded that a single bout of electrical stimulation exercise resulted in greater GH response and muscle damage than voluntary exercise. neuromuscular electrical stimulation; isometric strength; blood lactate; creatine kinase; muscle soreness IN RECENT YEARS, THE ACUTE effects of neuromuscular electrical stimulation (NMES) on neuromuscular and metabolic responses have received attention (16,28,33,37,39). It has been reported in several studies that electrically evoked contractions result in greater strength loss and greater increases in oxygen consumption and blood lactate compared with voluntary contractions at the same intensity (16,28,33,37,39). It has been speculated that the specific recruitment pattern of motor units during NMES is mainly attributed to the phenomena (16,28,37,39). Indeed, it is documented that the recruitment of motor units during stimulated contractions is different from voluntary contraction such that fast-twitch fibers could be activated at relatively low force levels (i.e., random/nonselective motor unit recruitment) (10,17,20,30).It is known that acute voluntary resistance exercise increases growth hormone (GH) secretion (for review see 22); however, limited information is available for acute GH responses to NMES. To the best of our knowledge, only two studies have reported GH responses to NMES. Greisen et al. (11) showed a significant increa...

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“…The adopted protocol for ERE induced no alarming CK responses, which could be indicative of excessive muscle damage. Furthermore, the CK reference values for women are 40 to 150 U/l [14). Although the magnitude of CK activity after exercise was small, when accompanied with NO increments after exercise in the HR subjects, it could be indicative of muscle damage and regeneration [28].…”

Section: Discussionmentioning

confidence: 99%

“…Changes in serum CK concentration has been previously used as an indicator of muscular damage [12], and is still used in recent studies [13]. A particular problem in using serum CK concentration is due to its inter-subject variability, especially following exercise [14]. Similar baseline serum CK values and notable inter-subject variability after exercise, justifies classification of low and high responders and it can be partially explained by body composition [15], training status [15], and genetic factors [16].…”

Section: Introductionmentioning

confidence: 99%

Understanding responsiveness of nitric oxide to acute eccentric resistance exercise in elderly obese women

Ddc

et al. 2016

J Clin Transl Res

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Background and Aim:The aim of the present study was to examine nitrite concentration responses following eccentric resistance exercise (ERE) in elderly obese women. We also investigated the existence of high (HR) and low responders (LR) for nitrite and the possible differences with respect to creatine kinase (CK) response, metabolic and body composition variables. Methods: Forty-nine elderly obese women completed an ERE session utilizing knee extensor exercise. LR for serum nitrite were defined as a ∆nitrite ≤ 20th percentile or 24.1 µmol/L and HR as a ∆nitrite > 20th percentile. Results: Ten subjects were classified as LR and the remaining as HR (n = 39). The HR group displayed greater nitrite concentration at 0 h, 3 h, 24 h and 48 h following the ERE as compared with the LR (p < 0.05), and CK increased after 24 h and 48 h only for the HR group following the ERE (p < 0.05). Peak nitrite concentration was higher in the HR group versus the LR group (p < 0.05), while there was no difference between groups for pre-exercise nitrite values. The LR group displayed higher (p < 0.05) body fat, cholesterol, LDL and lower upper limb fat-free mass as compared with the HR group. The LR had lower (p < 0.05) upper limb fat-free mass than the HR group. Conclusions: Elderly obese women classified as HR displayed higher nitrite responses to ERE. Thus, researchers should be aware of the presence of different responsiveness of nitrite to acute exercise to avoid misinterpretation of data and to identify the higher cardiovascular risk factor of those classified as LR. Relevance for patients: The elevated NO up to 48 h following an ERE session may suggest an important protective cardiovascular effect. The higher body fat, cholesterol, LDL and lower upper limb fat-free mass in the LR group might represent a deleterious effect of lower serum levels of nitrite. Keywords:aging exercise nitric oxide synthase nitrite obesity responders

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Creatine kinase isoforms following isometric exercise

Cited by 30 publications

References 16 publications

Angle-specific impairment of elbow flexors strength after isometric exercise at long muscle length

Angle-specific impairment of elbow flexors strength after isometric exercise at long muscle length

Comparison between voluntary and stimulated contractions of the quadriceps femoris for growth hormone response and muscle damage

Understanding responsiveness of nitric oxide to acute eccentric resistance exercise in elderly obese women

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