Until recently, most people stretched before exercise. Stretching was thought to increase joint range of motion, prevent injury and increase performance. Many recent studies showed that stretching does just the opposite. It decreases strength and power output and might increase the risk or inquiry. Scientists speculate that stretching interferes with nervous control of movement. Is all pre-exercise stretching bad? A study from the University of Oklahoma by Trent Herda and co-workers found that static strength and activation capacity, but dynamic stretching decreased muscle strength and activation capacity, but dynamic stretching didn’t. Dynamic stretching involves actively going through a range of motion, while static stretching involves holding a stretch for 30 seconds at a time. We need more research on the optimum warm – up procedure and the risks and benefits of stretching. Actively working muscles and joints through their normal

ranges of motion before exercise does not impair strength and might actually activate them for better performance during competition or intense exercise.

Fast curl – ups recruit the most muscle fibers

Most bodybuilders believe that slow, controlled contractions during weight training activate the muscle fibers best. Spanish researchers found the opposite – at least for curl – ups. They measured abdominal muscle activation levels during fast and slow curl-ups by electromyography (EMG).They attached electrodes to the rectus abdominis (six – pack muscle), internal and external obliques (side abs) and the erector spinae (spinal) muscles. They measured muscle activity while the subjects did curl – ups at four different speeds ranging from 1 rep per 4 seconds to maximum – speed curl – ups. Activation levels increased in each muscle as speed increased. They concluded that doing curl-ups at fast speeds was best for overloading the abdominal muscle and building dynamic spinal stability. Don’t do ab exercises so fast that you can’t maintain good technique.

Many athletes and coaches think that large – diameter bars increase muscle stress and fiber activation during exercises such as the bench press. Also, some coaches recommend training with different bar widths to vary the stress of exercise and increase grip strength.

Douglas Fioranelli and Matthew Lee from San Francisco State University concluded that bar diameter did not affect performance during an isometric bench press. They measured isometric force output at two joint angles (chest and halfway to lockout) using a thick bar (51 millimeters) and a standard Olympic bar (“thin;” 28 millimeters). The standard thin Olympic bar caused the greatest muscle activation at halfway lockout. Isometric exercise might not be the best way to measure the effects of bar width on performance. They might have found different results if they had used a dynamic exercise. This was an interesting study, but we need more research to help assess the effects of the bar width on strength, training load and muscle activation. (Journal Strength Conditioning Research, in press; published online May 2008)

Dehydration decreases performance during endurance exercise in the heat and is the kiss of death in events such as the marathon and triathlon. Athletes in high-power sports such as soccer, volleyball and tennis often get dehydrated while playing in the heat. Yet, we don’t know such about the effects of hydration levels on performance in these sports. A study led by Leon Jones from Chicago State University showed that dehydration decreased upper body power by 7 percent and lower body power by 19 percent, as measured by upper and lower body Wingate tests (all-out 30-second test on a stationary bike or arm ergo meter). The subjects were dehydrated through treadmill exercise and rested 1.5 hours before taking the power tests. The subjects said their fatigue levels were 70 percent greater than when they took the tests while normally hydrated, even though they said they were equally motivated. The authors concluded that dehydration impairs performance and might increase the risk of injury in athletes playing high-power sports. (Journal Strength Conditioning Research, 22: 455-463, 2008)

How much do you bench? Every guy in America with any athletic talent asks this question when trying to compare his strength with other men. The bench press is the most popular exercise in the gym and is a general measure of strength. Most strong guys can tell you when they achieved landmark bench presses of 205, 225, 300, 350 and 400 pounds. He who lives by the bench, dies by the bench. Almost all old bench pressers have bad shoulders- usually because of the technique they used to push the big iron. Many athletes prefer using a wide grip when they bench, because they don’t have to push the bar as far. This could be a mistake. Using a wide grip that places the hands greater than 1.5 times the acromial width (measured at the bony endpoints of the shoulders) causes excessive abduction (elbows out) of the shoulders during the exercise. This places high levels of torque on the shoulder joint that can cause arthritis, shoulder cartilage injury, rotator cuff tears and pectoral is major rupture. Athletes can decrease range of motion during a bench press by using a better “bench press stance.” Get under you when you bench, bring your shoulder blades together and brace (tighten) your thigh, butt and core muscles. This will stick your chest out and give you a powerful platform from which to bench press. It will also save your shoulders. Good technique doesn’t hurt. Do this exercise correctly and you can bench big weights without becoming a bench press cripple when you hit 30 years of age. (Strength Conditioning Journal, 29: 10-14, 2007)

One measure of a champion bodybuilder or power athlete is the capacity to train hard, recover quickly and train hard again. Intense eccentric exercise (negatives or lengthening contractions) causes muscle damage, post-exercise soreness and delayed recovery. Remedies such as massage, heat, cold and nonsteroidal anti-inflammatory drugs (e.g., Advil) do not speed recovery or restore normal strength and power more than rest alone. British researchers found that men who took 100 grams of protein (containing 40 grams of essential amino acids) after an exercise designed to cause muscle soreness and damage (30 minutes of down hill running) showed higher strength levels 24 and 48 hours after exercise compared to a control group. Strength decreased by 8 percent in the control group (fake protein) 24 hours after exercise and decreased 10 percent at 48 hours. Strength remained at pre-exercise levels in the protein group during the entire recovery period. This study showed that taking a supplement containing a large amount of protein (100 grams) promoted recovery and would presumably allow more intense training. It is not known whether this technique would continue to work during repeated exercise sessions. (Applied Physiology Nutrition Metabolism, 33: 483-488, 2008)

Nitric oxide (NO) is a gas secreted by the cells lining the blood vessels that helps regulate blood flow. It is also a poisonous air pollutant that is produced by cars and power plants. NO works by relaxing the muscles surrounding the blood vessels, which increases blood flow. The erection-promoting drug Viagra works by stimulating nitric oxide release in the penis. During exercise, blood flow increases to areas where it is needed, as long as blood pressure can be maintained researchers from Canada and the Mayo Clinic concluded that nitric oxide is not absolutely necessary for increasing muscle blood flow during exercise. Rather, it assists with other mechanisms such as increased pressure on the blood vessels, the muscle pump (muscles squeeze blood toward the heart), and chemical produced during exercise to stimulate blood flow. Nitric oxide is only one of many ways the body increases blood flow to muscles during exercise. (Applied Physiology Nutrition Metabolism, 33: 151-161, 2008)

The body is approximately 70 percent water, but even a small water loss impairs metabolism and cardiovascular function and decreases performance. Researchers from Chicago State University, led by Leon Jones, found that dehydration (3 percent) included by treadmill exercise in the heat increased the perception of fatigue by 70 percent and decreased upper and lower body power by 7 percent and 19 percent. They concluded that dehydration decreases performance in power sports and increase the risk of injury. Good strategies for improving exercise performance in the heat include maximizing physical fitness. Taking regular water breaks, training during cooler times of the day and drinking water before exercise begins. A good fluid replacement beverage should be cold and contain energy (7 grams carbohydrate per hundred milliliters of water) and electrolytes. (Journal Strength Conditioning Research, 22: 455-463, 2008)

Tapering or peaking is a training technique of systematically decreasing training load to boost peak fitness and performance. Fitness reflects training stresses and genetic ability. Athletes interested in maximum performance should train hard to boost strength, power, speed, endurance and muscle size (depending on the sport). They will experience a rapid increase in performance if they cut down on training volume for several weeks before a competition. This process is called is called peaking or tapering. Jacob and Gabriele Wilson described a practical approach to tapering. Tapering is tricky: reducing the workout intensity and volume too soon decreases fitness, while working too hard close to competition compromises recovery and peak performance. They concluded that a two-week taper that gradually reduces the training volume by 50-70 percent, without changing the training intensity or frequency is best for maximizing performance during the target competition. In other words, do short, high-intensity training sessions beginning two weeks before competitions or games. Cut down on volume, but not intensity. (Strength Conditioning Journal, 30: 10-17, 2008)

Pre-exercise stretching was once part of the normal warm-up ritual of almost all strength, power, and endurance athletes. Most fitness experts said that stretching increased muscle and joint range of motion, which made movements easier and reduced the risk of injury. It turns out that pre-exercise stretching is a bad idea that decreases performance and increases the risk of injury. Pre-exercise stretching reduces muscle strength and power and interferes with the brain’s ability to control the muscles. Greek researchers found that muscle power decreases the longer you stretch the muscle. They measured the effects of stretches lasting from 10 seconds to 60 seconds on isometric strength and power. Stretching for 30 seconds decreased isometric strength by nearly 9 percent, while stretching 60 seconds decreased power by 16 percent. Stretching 30 seconds or longer has similar effects in decreasing muscle power. They recommended that athletes avoid static stretching of muscles for 30 seconds or more before activities requiring maximum strength and power. (Journal Strength Conditioning Research, 22: 40-46, 2008)