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The_Bulldog:
Runners: Train Less and Be Faster

In a recent scientific study just published in the Journal of Applied Physiology, Bangsbo and co-workers demonstrate that by reducing the volume of training by 25% and introducing the so-called speed endurance training (6-12 30-s sprint runs 3-4 times a week), endurance trained runners can improve not only short-term but also long-term performance.

Thus, the runners improved their 10-km time by 1 min from 37.3 to 36.3 min after just 6-9 weeks of changed training. Six of the participating 12 runners obtained a new personal record on the 10-km, despite having been training for more than 4 years. The most impressive achievement was the one runner who lowered the time with more than 2 minutes from 37.5 til 35.4 min. In addition, performance in a 30-s sprint test and an intense exhaustive run (about 2 minutes) was improved by 7% and 36%, respectively. In agreement, the authors have previously shown that an 85% reduction in training volume can improve short-term performance (see right column).

In association with the improved performance the amount of muscle Na+/K+ pumps was elevated and the rate of accumulation of potassium during exercise was lowered, and it is speculated that this may play a significant role for the increased performance.

ScienceDaily (Nov. 15, 2009)

The_Bulldog:
Four Weeks of Ketosis Diet in Trained Athletes

To study the effect of chronic ketosis on exercise performance in endurance-trained humans, five well-trained cyclists were fed a eucaloric balanced diet (EBD) for one week providing 35-50 kcal/kg/d, 1.75 g protein/kg/d and the remainder of kilocalories as two-thirds carbohydrate (CHO) and one-third fat. This was followed by four weeks of a eucaloric ketogenic diet (EKD), isocaloric and isonitrogenous with the EBD but providing less than 20 g CHO daily. Both diets were appropriately supplemented to meet the recommended daily allowances for vitamins and minerals. Pedal ergometer testing of maximal oxygen uptake (VO2max) was unchanged between the control week (EBD-1) and week 3 of the ketogenic diet (EKD-3). The mean ergometer endurance time for continuous exercise to exhaustion (ENDUR) at 62%-64% of VO2max was 147 minutes at EBD-1 and 151 minutes at EKD-4. The ENDUR steady-state RQ dropped from 0.83 to 0.72 (P less than 0.01) from EBD-1 to EKD-4. In agreement with this were a three-fold drop in glucose oxidation (from 15.1 to 5.1 mg/kg/min, P less than 0.05) and a four-fold reduction in muscle glycogen use (0.61 to 0.13 mmol/kg/min, P less than 0.01). Neither clinical nor biochemical evidence of hypoglycemia was observed during ENDUR at EKD-4. These results indicate that aerobic endurance exercise by well-trained cyclists was not compromised by four weeks of ketosis. This was accomplished by a dramatic physiologic adaptation that conserved limited carbohydrate stores (both glucose and muscle glycogen) and made fat the predominant muscle substrate at this submaximal power level.

The_Bulldog:
Stretching Decreases Muscle Strength Power

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)

The_Bulldog:
Training To Failure: How Much And How Often?

Feeling the burn and pushing reps to the max have always been part of effective training for bodybuilding. Failure training involves doing an exercise until the muscles no longer respond. Jeff Willardson from Eastern Illinois University discussed the pluses and minuses of failure training methods. Many studies have examined the optimal number of sets in a program, but few have looked at the effects of failure training on muscle size and strength. Failure training allows advanced bodybuilders and lifters to break training plateaus and move to the next level. These highly intense workouts must be incorporated into short-term cycles to avoid overtraining. Failure training is effective, because it recruits more motor units (muscle fibers and their nerve supply) and stimulates the secretion of anabolic hormones such as growth hormone, insulin-like growth factor and testosterone and increases insulin sensitivity (insulin is a powerful anabolic hormone). Increases in strength require high-intensity overload, so bodybuilders should not rely on high-rep burn programs for making progress. Bodybuilders and power athletes must push the big iron if they want to get strong and big. Excessive failure training leads to injury, overtraining and loss of motivation. Failure training can move you to the next level, but don’t overdo it.

(Journal Strength Conditioning Research,21: 628–631, 2007)

The_Bulldog:
Cardio Protects Blood Vessels from Harmful Effects of Weight Training

Weight training increases muscle and bone mass and has positive effects on metabolism. It can, however, stress the blood vessels. At rest the average blood pressure is about 100 millimeters of mercury (mmHg.). Peak systolic blood pressure (higher blood pressure number) during heavy squats is as high as 400 mmHg. A single weight-training workout stiffens
the blood vessels, which could gradually damage the cells lining the vessels and stress the heart. Cardio on the other hand, makes the vessels more compliant and enhances their health and function. Japanese researchers found that doing cardio exercise after weight training promoted blood vessel health and compensated for the negative effects of weight training on blood vessel stiffness. Doing cardio before weight training did not provide a protective effect. Performing cardio after weight training benefits blood vessels and maximizes the training effects of resistive exercise, because you can lift more intensely with less fatigue.

(Journal Applied Physiology, 103:1655–1661, 2007)

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