L-Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

L-carnitine tartrate has been shown to improve relatively short-term recovery among athletes. However, there is a lack of research on the longer-term effects in the general population. Objective: The primary objectives of this randomized double-blind, placebo-controlled trial were to evaluate the effects of daily L-carnitine tartrate supplementation for 5 weeks on recovery and fatigue. Method: In this study, eighty participants, 21- to 65-years-old, were recruited. Participants were split into two groups of forty participants each, a placebo, and a L-carnitine Tartrate group. Seventy-three participants completed a maintenance exercise training program that culminated in a high-volume exercise challenge. Results: Compared to placebo, L-carnitine tartrate supplementation was able to improve perceived recovery and soreness (p = 0.021), and lower serum creatine kinase (p = 0.016). In addition, L-carnitine tartrate supplementation was able to blunt declines in strength and power compared to placebo following an exercise challenge. Two sub-analyses indicated that these results were independent of gender and age. Interestingly, serum superoxide dismutase levels increased significantly among those supplementing with L-carnitine tartrate. Conclusions: These findings agree with previous observations among healthy adult subjects and demonstrate that L-carnitine tartrate supplementation beyond 35 days is beneficial for improving recovery and reducing fatigue following exercise across gender and age.

Association between Levocarnitine Treatment and the Change in Knee Extensor Strength in Patients Undergoing Hemodialysis: A Post-Hoc Analysis of the Osaka Dialysis Complication Study (ODCS)

“…Supplementation of levocarnitine and other carnitine derivatives are also known to improve muscle wasting signs and symptoms in various conditions such as neurofibromatosis type 1 [39] and sarcopenia in chronic liver disease [40]. Furthermore, carnitine supplementation also improves recovery and reduces fatigue following exercise in the general population [41]. These results warrant further research of levocarnitine as a treatment of sarcopenia and muscle wasting in various populations.…”

Nutritional Compounds to Improve Post-Exercise Recovery

“…l -Carnitine, an amino acid derivative that is primarily stored in the skeletal and cardiac muscles [ 151 ], plays an essential role in fatty acid oxidation by facilitating the transport of acetyl groups into the mitochondria to allow energy production through beta-oxidation. In addition, l -carnitine has been demonstrated to improve the antioxidant status and reduce oxidative stress [ 151 ].…”

“…l -Carnitine, an amino acid derivative that is primarily stored in the skeletal and cardiac muscles [ 151 ], plays an essential role in fatty acid oxidation by facilitating the transport of acetyl groups into the mitochondria to allow energy production through beta-oxidation. In addition, l -carnitine has been demonstrated to improve the antioxidant status and reduce oxidative stress [ 151 ]. Endogenous synthesis of l -carnitine provides about 25% of a human’s daily requirement for the compound, and the remainder must be ingested in the diet, with red meat being the richest source [ 152 ].…”

“…As a supplement, l -carnitine is generally ingested as l -carnitine l -tartrate (LCLT) to increase its bioavailability and speed up its absorption [ 153 ]. Ingestion of LCLT for 2–3 weeks prior to a muscle-damaging exercise bout has been associated with reduced muscle soreness in the post-exercise recovery period in trained and untrained, young [ 151 , 154 ] and older (45–60 years) [ 155 , 156 ] adults with corresponding attenuation of multiple markers of muscle damage. The ability of l -carnitine supplementation to enhance muscle function in the post-exercise period has varied between studies.…”

“…However, this may have been due to the use of inappropriate tests (mobility and hand grip exercises) to assess muscle function [ 154 , 155 ]. A recent study that assessed countermovement and squat jump performance in the days following a muscle-fatiguing lower body resistance-based exercise challenge recorded improvements in muscle function when a 5-week l -carnitine supplementation protocol was used [ 151 ].…”