Effects of Prolonged L-Carnitine Administration on Delayed Muscle Pain and CK Release After Eccentric Effort

Abstract

Eccentric muscle effort is known to induce delayed muscle soreness (DOMS) and muscle damage which are not responsive to medical treatment with the most common analgesic agents. The aim of the study was to investigate the effects of oral L-carnitine supplementation on pain (VAS scale), tenderness (pain thresholds) and CK release induced by a 20-min eccentric effort of the quadriceps muscle. A single-blind study was carried out on 6 untrained subjects (mean age: 26 +/- 3.8 yrs; mean height: 173 +/- 4.6 cm; mean body weight, 68.3 +/- 4.5 kg) over 7 weeks during which each subject: a) was given 3 g/day of placebo for 3 weeks and, after a week's interval, 3 g/day of L-carnitine for 3 weeks: b) performed 2 step tests on the first day of the 3rd and 7th week inverting the order of the exercising limb. In a separate set of experiments carried out 8 months later, the possible effects of training on pain parameters and CK levels were also investigated in the same subjects who performed 2 step tests at a 4-weeks' interval, without medication. L-carnitine significantly reduced pain, tenderness and CK release after the effort with respect to placebo. In contrast, no significant difference was found in the parameters measured between the two tests performed without medication. It is concluded that L-carnitine has a protective effect against pain and damage from eccentric effort. This effect is mainly attributed to the vasodilatation property of the compound, which both improves energetic metabolism of the hypoxic/damaged muscle and enhances wash-out of algogenic metabolites.

l-Carnitinel-tartrate supplementation favorably affects markers of recovery from exercise stress

“…The lack of a creatine kinase response to exercise during LCLT is indicative of less disruption to the sarcolemma. Similar to our findings, Giamberardino et al (7) demonstrated that the creatine kinase responses to a 20-min eccentric step test were attenuated in subjects that consumed 3 g carnitine/day for 3 wk before exercise.…”

Nutritional Interventions as Potential Strategy to Minimize Exercise-Induced Muscle Injuries in Sports

“…These studies demonstrated that supplemental carnitine is effective in attenuating tissue damage as directly assessed via magnetic resonance imaging, muscle soreness, and postexercise markers of metabolic stress following eccentric exercise training [102] or intense resistance exercise [103][104][105] thus leading to a quicker recovery (2 to 3 g/day of elemental carnitine being supplied by L-carnitine L-tartrate, LCLT). In particular Volek and colleagues [103] analyzed the effects of L-carnitine (2g/d for 3 wk before exercise and during 4d recovery) on markers of muscle damage in trained adult man following 5 sets of 15-20 repetitions of squats at 50% of 1-RM.…”

“…Furthermore ROS generated beyond physiological limits are found to reduce muscle force production by altering calcium ion sensitivity in muscle and thus contributing to muscle fatigue [107] [108,109]. Lcarnitine supplementation has been related to reduced postexercise CK [102,103] and myoglobin [103,105] concentrations suggesting that reduced oxidative stress may play a role in a quicker muscle recovery from strenuous exercise following supplementation. As a matter of fact early studies by Brass et al (1993) [110] demonstrated that L-carnitine delays hypoxiainduced fatigue in electrically stimulated rat skeletal muscle in vitro through its key stimulatory role in muscle bioenergetics and antioxidant activity.…”

Carnitine and Its Derivatives in Cerebrovascular Diseases

“…С помощью приема 2 г карнитина ежедневно бе гу-ны-стайеры улучшали спортивные показатели на 6%, что достаточно было для превращения участни-ка соревнований в чемпиона. [6]. Работа А. Френ ке-ля о необходимости карнитина для роста экспе ри-ментальных животных (1952) имела многочислен ные продолжения, которые позволили провозгласить карнитин незаменимой аминокислотой если не для взрослых, то для маленьких детей, особенно находящихся на искусственном вскармливании.…”