Endurance & Weight Control
Bright Performance Without Burning Out
PHYSICAL ENDURANCE AND MUSCLE RECOVERY
Work, Sport, Leisure – in fact all physical activity will generate reactive oxygen species (ROS); the more intense the activity the greater number of free radicals. ROS are shown to have damaging effects on muscle performance and recovery. Published and on-going research, focused on improving endurance and reducing recovery time, are showing dramatic benefits linked to the potent carotenoid - astaxanthin. These findings are bringing astaxanthin to the forefront as a dietary supplement for professional athletes and physically active people.
Important to physical activity are our mitochondrial cells, often referred to as the “power stations of the cell” , which provide as much as 95% of our body’s pure energy (primarily by the burning of muscle glycogen and fatty acids). Unfortunately, a portion of this energy produces highly reactive and damaging ROS. ROS damage cells by triggering peroxidation of the cell membrane components, and oxidation of DNA and proteins. Furthermore, ROS continue to affect muscles even after the strenuous exercise has ceased. ROS activate the inflammation response whereby monocytes migrate into the muscle tissue causing additional cell damage. Often we will notice the onset of muscle damage during recovery in the form of tiredness and soreness. In addition to improving muscle performance through devised exercise regime, the sports research community is looking at other methods, such as nutrition to fuel and protect the body under extreme physical conditions. In the past, Vitamins E and C helped make the use of antioxidants a popular tool against oxidative damage during intense physical activity. Today, informed by current research we can point to astaxanthin as the antioxidant of choice for sports performance. Astaxanthin demonstrated 3 important physical benefits in clinical trials and supporting studies. Astaxanthin increased endurance, reduced muscle damage and improved lipid metabolism.
Astaxanthin Boost Endurance
In a randomized, double-blind, placebo controlled study on healthy men supplemented with 4 mg astaxanthin per day for up to 6 months at Karolinska Institute, Sweden, standardized exercise tests demonstrated that the average number of knee bends performed increased only in the astaxanthin treated group at 3 months, and by the 6 month significant improvements were observed (Figure 1) (Malmsten & Lignell, 2008). Furthermore, mice model studies by Ikeuchi et al., (2006) showed that swimming endurance increased significantly (p<0.01) from one week of astaxanthin intake at 6 and 30 mg/kg body weight (Figure 2).
Astaxanthin improved strength/endurance at 3 and 6 months determined by the average number of knee bends per person.
Figure 2. Effect of astaxanthin on swimming time (Ikeuchi et al., 2006)
Astaxanthin improves endurance in a dose-dependant manner.
In another study, Aoi et al., (2008) demonstrated that astaxanthin may modify muscle metabolism by its antioxidant property and result in improved muscle performance and weight loss benefits. After 4 weeks the mice running time to exhaustion had significantly improved by up to 20 % (p<0.05) with astaxanthin. In addition, Sawaki et al., (2002) of Juntendo University, Japan, demonstrated by using 1200 meter track athletes, that a daily dose of 6 mg per day for 4 weeks resulted in their bodies accumulating lower levels of lactic acid (Figure 3). Ikeuchi et al., (2006) also reported the same findings and furthermore, astaxanthin efficacy had a dose-dependent response (Figure 4).
Figure 3. Reduction of lactic acid build-up after astaxanthin supplementation in track subjects (Sawaki et al., 2002)
Figure 4. Effect of astaxanthin on blood lactate during swimming for 15 minutes (Ikeuchi et al., 2006)
Astaxanthin reduced build-up of lactic acid in a dose-dependant manner.
In a double blind controlled placebo study, healthy women (n= 32; age-23-60) who ingested 12 mg of astaxanthin for 6 weeks significantly reduced their body fat (4%) when conducting routine walking exercise, compared to a placebo group. In addition, while control group increased their lactic acid by 31% compared to the astaxanthin group - only 13% (p<0.05). The same female participants who ceased oral administration of astaxanthin after the study were retested four weeks later and their body fat level rose again to the level observed at the start of study (Fukamauchi, 2007).
The Mechanism
The mechanism behind muscle endurance is based on several findings. Generally, astaxanthin protected the skeletal muscle from the increased damage of oxidative stress generated by physical activity. Furthermore, astaxanthin increased the metabolism of lipids as the main source of energy production by protecting the carnitine palmitoyltransferase I (CPT I) involved in fatty acid transport into mitochondria. Aoi et al., (2003) of Kyoto Prefecture University used mice models that may partially explain the efficacy of astaxanthin; they compared control, exercise placebo, and astaxanthin treated exercise groups after intense physical activity. 4-hydroxy-2-nonenal-modified-protein (4-HNE) stain analyses of the calf (gastrocnemius) muscles revealed significantly lower peroxidation damage (Figure 5).
Figure 5. Effect of astaxanthin on 4-HNE-modifed proteins in leg muscle before and after exercise (Aoi et al., 2003)
Other biochemical markers for oxidative damage and inflammation such as DNA (p<0.05), creatine kinase (p<0.05) and myeloperoxidase activity (p<0.05) were significantly reduced in the astaxanthin treated exercise group. These effects indicate that astaxanthin has a role in helping protect muscle cell components and down modulating the inflammatory processes. Lee et al., (2003) also explained that astaxanthin directly modulates inflammation caused by the release of the pro-inflammatory cytokines and mediators. In vivo and in vitro tests demonstrate that astaxanthin inhibits the IκB Kinase (IKK) dependant activation of the Nuclear Factor-kB (NF-κB) pathway, a key step in the production of pro-inflammatory cytokines and mediators.
Aoi et al., 2008 also demonstrated increased lipid metabolism compared to carbohydrate as the main source of energy during strenuous activity (Figure 6). Furthermore, analysis of the mitochondrial lipid transport enzyme known as carnitine palmitoyltransferase I (CPT I) revealed increased fat localization (Figure 7) and reduction of oxidative damage in the presence of astaxanthin (Figure 8). CPT I is important because it regulates fatty acyl-CoA entry into the mitochondria in the oxidation of fatty acids in muscle. Exercise-induced ROS may partly limit utilization of fatty acid via diminishing CPT I activity.
OUTLOOK
Strenuous physical activity generates high levels of ROS which affect muscle performance and metabolism of lipids. New research shows that astaxanthin can modify muscle metabolism via its antioxidant effect, resulting in the improvement of muscle function during exercise. Therefore, astaxanthin is expected to be useful for physically active people as well as athletes
