^ Southren AL, Gordon GG, Tochimoto S, Pinzon G, Lane DR, Stypulkowski W (May 1967). "Mean plasma concentration, metabolic clearance and basal plasma production rates of testosterone in normal young men and women using a constant infusion procedure: effect of time of day and plasma concentration on the metabolic clearance rate of testosterone". The Journal of Clinical Endocrinology and Metabolism. 27 (5): 686–94. doi:10.1210/jcem-27-5-686. PMID 6025472.
Retinol (Vitamin A) B vitamins: Thiamine (B1) Riboflavin (B2) Niacin (B3) Pantothenic acid (B5) Pyridoxine (B6) Biotin (B7) Folic acid (B9) Cyanocobalamin (B12) Ascorbic acid (Vitamin C) Ergocalciferol and Cholecalciferol (Vitamin D) Tocopherol (Vitamin E) Naphthoquinone (Vitamin K) Calcium Choline Chromium Cobalt Copper Fluorine Iodine Iron Magnesium Manganese Molybdenum Phosphorus Potassium Selenium Sodium Sulfur Zinc
The Organon group in the Netherlands were the first to isolate the hormone, identified in a May 1935 paper "On Crystalline Male Hormone from Testicles (Testosterone)". They named the hormone testosterone, from the stems of testicle and sterol, and the suffix of ketone. The structure was worked out by Schering's Adolf Butenandt, at the Chemisches Institut of Technical University in Gdańsk.
Competitive and professional bodybuilders, however, can often build up to two to three pounds of muscle per month during dedicated bulking periods. "But they are living and breathing muscle growth. They aren't just in and out of the gym like most people," Simpson says, noting that under extreme conditions, hyperplasia, or the growth in the number of muscle cells in a given muscle tissue, may actually occur, further adding to muscle growth results.
Mitochondrial myopathies are a subgroup of mitochondrial cytopathies in which the skeletal muscle is negatively influenced. They are characterized by weaknesses in muscular function and energy metabolism. These particular myopathies are thought to benefit from creatine supplementation, since creatine can help with some of the dysregulated energy production.
Creatine is an energy substrate: a small peptide serving as a reservoir for high-energy phosphate groups that can regenerate ATP, the main currency of cellular energy. An increase in creatine intake (through food or supplementation) increases cellular energy stores, promoting the regeneration of ATP in the short term. Stores are limited, however, and glucose or fatty acids are responsible for ATP replenishment over longer durations.
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition. The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression. Thus it is the challenge of competition among males of the species that facilitates aggression and violence. Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels. The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.
Weight trainers commonly spend 5 to 20 minutes warming up their muscles before starting a workout. It is common to stretch the entire body to increase overall flexibility; however, many people stretch just the area being worked that day. The main reason for warming up is injury prevention. Warming up increases blood flow and flexibility, which lessens the chance of a muscle pull or joint pain.
Endurance exercise is also known to produce heat from skeletal muscle tissue, and an increase in internal temperature occurs when the production of heat (from metabolism) exceeds release. This increase in heat is accelerated when training in hot environments and it is thought to be beneficial to retain water (hydration) during exercise, since more water allows a preservation of plasma volume (PV) and the sweat response reduces internal temperature. This particular phenomena may only apply to endurance exercise, since creatine is able to increase sprint performance in heat, independent of altering the decline in PV and sweat rates.
Sugar is to testosterone what kryptonite is to Superman. Eliminating sugar is probably the single most powerful way to increase your performance, in part because sugar absolutely devastates your testosterone levels (but all carbs do not, especially under heavy training.) In one study of 74 men, a 75g dose of sugar – about the equivalent of a bottle of soda – decreased serum testosterone by 25% in under an hour, and levels stayed low for at least 2 hours . On top of that, 15% of the men who started with normal testosterone dipped into the hypogonadal range after they ate sugar – that’s the range in which doctors diagnose men’s testes and women’s ovaries as failing. When you do eat carbs, stick to Bulletproof ones like sweet potatoes and squash. My recommendations for types of carbs and how often to eat them are here.
Focus on form. Good form means you can reap all of the benefits of your workout and avoid injuries at the same time. To maintain proper form, pay attention to your posture (stand tall with chest lifted and abs held tight), move slowly (this ensures you're relying on muscles, not momentum, to do the lifting), and remember to breathe. Many people hold their breath while exerting, but exhaling during the hardest part of the exercise helps fuel the movement.