A column by Mike Furci that brings you research, trends and other info to help you with your fitness, health and nutritional needs.
… a new study found an association between L-carnitine, an amino acid found at high levels in red meat and heart disease risk. Dr. Stanley Hazen of the Cleveland Clinic, who led the study, tested the carnitine and TMAO levels of omnivores, vegans and vegetarians, and examined the clinical data of 2,595 patients undergoing elective cardiac evaluations. They also examined the cardiac effects of a carnitine-enhanced diet in normal mice compared to mice with suppressed levels of gut microbes, and discovered that TMAO alters cholesterol metabolism at multiple levels, explaining how it enhances atherosclerosis.
The researchers found that increased carnitine levels in patients predicted increased risks for cardiovascular disease and major cardiac events like heart attack, stroke and death, but only in subjects with concurrently high TMAO levels. It’s important to emphasize that in scientific terms association doesn’t show cause, and to be careful of the credence given because a study said so.
Meanwhile, a meta-analysis of 20 studies involving more than 1.2 million participants from 10 countries who were followed for up to 18 years, found no definitive association of daily consumption of red meat heart health (Boston.com). Heart disease does have a strong association with consumption of processed carbs and fats like vegetable oils and man-made trans fats (Fats, April 18,2006). It is important to keep in mind that there are many other studies done on L-carnitine that do not show any adverse health effects at a variety of doses. In fact, the National Institutes of Health fact sheet on L-carnitine shows it’s not only safe, but good for the heart and peripheral artery disease.
… that pre-workout stretching is still touted by many trainers and coaches. A study examined the effects of proprioceptive neuromuscular facilitation (PNF) stretching and static stretching (SS) on maximal voluntary contraction (MVC). Thirteen participants completed 3 different conditions on 3 nonconsecutive days in a random order: (SS), (PNF) and no stretching (control, CON). The MVC of knee and elbow flexion and the vastus lateralis muscles were measured. Researchers concluded although stretching has a positive effect on range of motion (ROM), it has been shown repeatedly to have a detrimental effect on muscular performance. ((2013). Journal of Strength and Conditioning Research, 27(1), 195-201)
Bottom line, stretch after your workouts to avoid reducing the musculotendinous stiffness, because hampers the excitability of the muscles being worked, thus hindering performance.