Whole-Body Vibration Between Sets Increases Squat Strength
Vibration training involves doing basic exercises, such as squats, push-ups, lunges, and modified pull-ups on a vibrating platform. Vibration is transferred through the feet, hands, or butt, which are in contact with the vibrating plate or handlebars. Vibration activates stretch receptors in the muscles, which triggers thousands of small reflex muscle contractions. Vibration may also stimulate bone synthesis and release hormones that promote muscle tone and decrease fat.
A University of Mississippi study showed that isometric squat strength increased slightly when athletes were subjected to whole-body vibration between sets. Vibration training increases strength and physical capacity in older adults and untrained people. It might be useful during rehabilitation from injury or when used during rest intervals between sets. It is not a magic bullet that will make you big and strong.
Chains for Variable Resistance Squats
Most serious powerlifters use chains to provide variable resistance during squats, bench presses, and deadlifts. Chains hung from the bar provide increased resistance as the lift progresses. Kurt Neelly and co-investigators from Bradley University in Peoria, Illinois, found that the double-looped chain technique (small chain connected to a larger chain) unloaded the bar by as much as 89 percent at the bottom of the lift, while linear hung chains (large chains connected directly to the bar) unloaded the bar by 42 percent. In both techniques, the chain weight is unloaded onto the floor at the bottom of the squat, and the load increases progressively as the athlete drives to the standing position and lifts the chains from the floor.
The study found that the double-looped chain technique increased the variable resistance at the top of the squat twice as much as the linear hanging chain technique. Chains increase the intensity of weight training.
Growth Hormone Higher in Two-Arm than One-Arm Training
Many bodybuilders practice unilateral (one arm at a time) training, to better isolate and build muscle. Anabolic hormones, such as growth hormone, testosterone, and insulin, help build muscle mass and strength.
A study led by William Kraemer from the University of Connecticut at Storrs found that two-arm training (bilateral training) produced greater increases in growth hormone than one-arm training, but there were no differences in testosterone or insulin. Athletes performed 5 sets of 10 reps of five dumbbell exercises. They exercised more intensely during two-arm training, which accounted for the greater increase in growth hormone levels. The amount of muscle mass activated during training is an important factor determining the anabolic hormone response.
Muscle Cramps Linked to Increased Nerve-Muscle Activation
Muscle cramps usually affect the large muscles of the thighs or calves during or immediately after exercise. They last for a few seconds to several minutes. Conventional wisdom is that dehydration, electrolyte imbalances (e.g., magnesium, potassium and sodium), accumulation of lactic acid, or low cellular energy levels cause exercise-induced muscle cramps.
New research showed that increased neuromuscular excitability is the cause. Overexercise results in central nervous system fatigue that inhibits muscle sensors that regulate muscle contraction. This interferes with muscle relaxation and causes muscle cramps. Risk factors include aging, poor biomechanics, and bad posture.
Static stretching can relieve cramping. Gently stretch the muscle for 15 to 30 seconds until it relaxes. Rest at least one hour after a cramp, to promote recovery of the central nervous system.
Caffeine Increases Short-term Exercise Capacity
Caffeine is among the most popular performance-enhancing drugs in the world. Athletes take caffeine to increase energy levels, boost strength and power, and speed metabolism to promote weight loss.
A review of literature by Todd Astorino and Daniel Roberson from California State University, San Marcos, concluded that caffeine improves endurance, high-intensity exercise performance, and strength. Most studies found that caffeine increased performance in team sport movements, power-based sports, and weight training. Side effects include anxiety, hyperactivity, cardiac arrhythmias, and insomnia. Many bodybuilders find that consuming small amounts of caffeine before workouts increases training intensity.
The National Collegiate Athletic Association has banned caffeine at levels greater than 15 mcg per millimeter— about six cups of coffee. It was removed from the World Anti-Doping Agency list of banned substances, but is currently on their ‘watch list.’
Squats Do Not Injure the Knees— If Done Correctly
Most sports movements begin in the athletic position— knees bent, butt down, kneecaps over the toes, shoulders square, back arched slightly with a small bend at the waist, chest over the knees, and the head in a neutral position. Squats build strength in this position. Sprinting fast or jumping high largely depends on the power of the glutes to extend the hips. No other exercise develops the glutes better than squats.
Rafael Escamilla and co-workers from California State University, Sacramento concluded that the parallel squat was safe for healthy knees. Squats caused minimal stress on the posterior and anterior cruciate ligaments in the knee. Compression of the kneecap and large bones of the lower body (femur and tibia) and the load on the quadriceps, hamstrings, glutes, and calves increased with the depth of the squat. Squats promote knee stability if done correctly.
Exercise Increases Production of Testosterone in Muscle
Most testosterone is produced in the testes in men and indirectly in the adrenal glands in both sexes. A University of Tokyo study on rats found that enzymes in skeletal muscle cause local production of testosterone in response to exercise. Testosterone is converted to the more biologically active dihydrotestosterone (DHT) by the enzyme 5alpha-reductase.
Exercise increased muscular DHEA, free testosterone, DHT, and 5alpha-reductase levels in males and females. The activity of the androgen receptors increased in females, but not males. Exercise increases muscle production of testosterone and similar hormones in males and females.
Sprint and Strength Workouts Interfere With Each Other
The genetic and biochemical mechanisms of adaptation to weight training and sprint training are different. John Hawley and colleagues from Australia concluded that mixing training methods causes interference in physiological adaptation. High-intensity muscle contractions, such as occur during bodybuilding or weightlifting, promote muscle strength and growth, while sprint training triggers metabolic changes, but does not increase muscle hypertrophy.
The order of training affected cellular adaptation. Sprinting, followed by weight training, interfered with muscle hypertrophy. Performing different types of exercise in close proximity (e.g., sprinting, followed closely by weight training) interfered with the muscular adaptation to strength training.
People adapt best to varying types of training best when they do them on separate days or at least at different times of the day. This is important information for bodybuilders and power athletes.
source:www.musculardevelopment.com
