Health News: By Rob WIlkins



The following information IS NOT medical advice and is solely intended for information purposes. Please consult your healthcare provider with questions related to the articles below.


C

The aging process is characterized by a reduction of the physical capacities of coordination, flexibility, strength, and power. Strength generally remains relatively high until 50 years of age when decreases of about 10% per year begin to result in a loss of function and independence; however, little is known about whether neuromuscular power declines in a similar manner or at the same rate as strength. The purpose of this study was to document the muscular strength and power of the upper and lower body and the relationships between the neuromuscular parameters of strength and power for 3 groups of men representing the 20–65-year age range.

Healthy, sedentary subjects were recruited into 3 age groups, 20–25 years (n = 10), 35–40 years (n = 8), and 50–65 years (n = 7). Following informed consent and medical clearance, measures of maximal strength (one repetition maximum) and power (piezoresistive accelerometry) were obtained for the upper (bench press) and lower body (leg press), and fat-free body mass was assessed by underwater weighing on 2 separate days. Within-day trial-to-trial reliability was assessed with intraclass correlation coefficients, whereas day-to-day reliability was assessed with Pearson correlation coefficients and dependent t-tests. Group differences were explored with analysis of variance and Tukey’s post hoc test, and statistical significance was set a priori at a probability level of p = 0.05.

Day-to-day reliability for each neuromuscular and body composition parameter was excellent for each age group. The oldest men had significantly more body fat (p < 0.01) but similar amounts of fat-free tissue when compared with the other groups, yet all measures of strength and power were significantly lower (p < 0.01) than the 2 younger groups. Additionally, even though strength and power are theoretically related, the statistical relationships between these 2 parameters were weakest for the oldest group of men and remained fairly independent of each other regardless of the age group being examined.

In conclusion, it appears that the ages of 50–65 years represents a critical period when factors other than the amount of fat-free tissue are responsible for the beginning decline in neuromuscular strength and power.

Source: The Journal of Strength & Conditioning Research: Vol. 13, No. 4, pp. 330–338.

MODIFIED WEIGHT LIFTING SAFE FOR OLDER ADULTS

Many studies have demonstrated that resistance training for senior citizens can be both safe and effective. A recent study has added to this group of research, and found that a properly designed weight-training program for seniors is safe for their hearts, too.

The study published in Medicine and Science in Sports and Exercise, involved 65 healthy adults (32 men and 33 women) ages 65 to 80. Weightlifting exercises consisted of two sets of 12 repetitions at 12-rep maximum (RM) weight, and four sets of five repetitions at 5RM for the leg press, seated chest press and leg extension. Cardiovascular tolerance to the weightlifting exercises was evaluated both physiologically and biologically by measuring heart rate and blood pressure continuously during exercise, and with a blood concentration test both before and after exercise. Comparisons between resting, exercise and postexercise results were then made.

Based on these results, researchers found that weightlifting exercises, if performed properly, including using proper respiratory techniques, are safe for older adults, even those just beginning an exercise program. Of course, such clients should have a medical evaluation before beginning an exercise program, and they should be supervised until they and their trainer know they can safely workout on their own.

Source: Medicine and Science in Sports and Exercise (Vol.32, No.11)

ENHANCE PERFORMANCE THROUGH SPECIFICITY
TRAINING


Your best gains in performance will be achieved when key parts of your training closely mimic what you do when you compete. In other words, if you specialize in a certain training protocol (specific to your sport), you will experience a substantial advantage in strength and endurance during competition.

This is absolutely true in running. Performing 5-minute intervals at your 5-K pace will do far more for your 5-K race performances than will long runs at slower paces, and carrying out 10-minute intervals at your 10-K race pace will improve your 10Ks more than 25-minute 'tempo runs' at a speed slower than 10-K velocity. It also applies to strength training. For example, scientific studies have shown that when individuals isometrically train their arm muscles at an elbow-joint angle of 150 degrees, they achieve major gains in strength at that specific elbow angle but almost no improvements at an angle of 60 degrees, even though exactly the same arm muscles are involved.

When strength athletes train with very heavy weights and therefore slow lifting velocities, they make major gains in their abilities to handle high resistances at slow speeds, but they're still very poor at lifting more moderate weights at high velocities. Conversely, when strength athlete’s train with moderate weights and high velocities, they become very adapt at such activity - but have little capacity to lift extremely heavy weights at slow speeds.

Expressed yet another way, the performance of slow, heavily loaded strength training tends to increase maximal strength but does not improve the rate at which athletes can apply force (i.e., it helps their strength but not their speed or power). On the other hand, doing explosive stuff makes athletes great at developing muscular force quickly, but maximal strength doesn't budge. The latter effect has been documented in work with plyometrically trained athletes. For example, athletes who carry out “drop jumps” during training (in a drop jump, an athlete jumps off a box or step, lands on the ground, and then explodes into the air as quickly as possible), develop useful upgrades in the rate at which they can develop force in their leg muscles. But their maximal leg strength may not increase.


FROM STRENGTH TRAINING TO RUNNING

Specificity also applies to the transference of improvements from strength training over to running. When most runners go to the gym, they focus on the usual, traditional, tried-and-true exercises that they've read about in magazines, heard about from other runners, and/or know how to do. These include bench presses, squats, power cleans, leg extensions, leg flexions, biceps curls, abdominal crunches, and calf raises. Such exercises are great for developing generalized strength, but there is one small problem: none of them has anything to do with running.

Basically, squatting makes you a better squatter. Bench presses improve the strength of your pectoralis and triceps muscles. Ab crunches help you get better at bringing your shoulders toward your hips and may make you look prettier at the beach. Leg extensions increase your quadriceps-muscle strength when you are in a seated position. None of them helps you run faster in your next 5K.

That's why we always recommend that runner’s carry out strength routines that are more specific to the muscular patterns associated with running. Instead of squatting, ab-crunching, and bicep curling, you should be carrying out exercises such as one-leg squats, high-bench step-ups, and one-leg hops in place, all of which closely mimic the overall body posture and muscle mechanics of running. And once you're good at doing such specific exercises, we recommend that you move on to strength routines which will help you exert muscular force in a rapid manner in a horizontal direction, i.e., toward the finish line of your race. High-speed bounding, running while attired in a weight vest, and hill repetitions will all help you do that.

Okay, you say, but where is the proof that such training is better than the traditional fare of leg extensions and bicep curls?

STRENGTH-TRAINING MODES COMPARED

Scientists at The Centre for Exercise Science and Sport Management of Southern Cross University in Lismore, Australia, divided 30 exercise-science students who had been engaged in weight training for a period of at least one year (all the subjects could perform a half-squat exercise with a load greater than body mass) into two different groups. One group, the control subjects, simply continued their normal training over an eight-week period. The second group also trained normally but added in two additional strength sessions per week, each consisting of four to six sets of six to 10 maximal-effort reps, with three-minute rests between sets. Only two exercises were used in the training - the squat and the bench press (each was completed for four to six sets per workout). Resistance was such that a subject could perform at least six, but no more than 10 reps (resistance was gradually increased over the eight-week period as the athletes became stronger).

At the end of eight weeks, both groups were assessed on a variety of tests of strength and power, including:

1) A bench-press throw at a load of 30 per cent of maximum (a bench-press throw is just like a bench press, except that you try to throw the weight as high as possible; fortunately, a special electro-magnetic braking system catches the weight before it can tumble back and strangle you);
2) A counter-movement jump (a vertical jump performed while swinging the arms back and then forward and up)
3) Maximal squats and bench presses (the two key exercises in the study);
4) A press-up test performed on a force platform to precisely measure force generated by the shoulders and arms (this was like a normal press-up except that subjects pushed against the platform with maximal force and attempted to rocket their upper bodies as quickly away from the ground as possible; their hands actually left the ground as their torsos moved upward);
5) A maximal 40-metre sprint;
6) A 6-second exercise-cycle test in which subjects tried to exert peak power, and
7) A series of tests designed to measure shoulder- and leg-muscle strength carried out on a Cybex machine.


Specificity wins

The results of these tests strongly supported the specificity-of-training principle. For example, if we focus only on the leg muscles for a moment, two of the tests - the maximal squat and the vertical jump - were very similar to the basic exercise used during training - squatting. The only difference between training squatting and test (competitive) squatting was that non-maximal loads were used during training. Similarly, the body posture and muscle-loading patterns of the vertical jump are very similar to what happens during squatting (both require a crouching position; both require that powerful forces be exerted in a vertical direction).

And how much improvement did the athletes make in maximal squatting and vertical jumping after eight weeks of squat training? A not-too-shabby 21 per cent! Maximal squatting capability climbed from 115 to 139 kg, and vertical jumping ability rose from 20.8 inches to 25.2 inches.

THE UPPER BODY

The story for the upper body was pretty much the same. The exercise utilized for upper-body training was the bench press, so it wasn't surprising that maximal bench-press prowess improved by 12.4 per cent after eight weeks (from 82 to 92 kg). Likewise, the bench-press throw, which mimics bench pressing exactly except that the bar is actually thrown vertically into the air, improved by 8.4 per cent.

However, here's the really good stuff: the athletes did not improve at all on the maximal press-up test, even though press-ups involve the same shoulder and arm muscles utilized during bench pressing. The difference, of course, as we saw in the squatting case, is not in the muscles actually utilized but in the specific way in which they are utilized.

The Australian researchers commented, “'The press-up test involved a similar action to the bench press and bench-press throw and employed a similar resistance, but it was performed in an inverted body position such that force was directed downwards, as opposed to vertically upwards.” In other words, training a particular muscle to be more powerful won't make that muscle more powerful in competition, unless the precise movement patterns used in training are very close to those used in competition.

Finally, 'arm-adduction power' (power exerted as an athlete's straightened arm is brought toward the middle of the body against resistance) was also unimproved after eight weeks, even though the key muscles involved in arm adduction - the pectoralis muscles - are the same ones that are the prime shakers and movers in bench pressing. By now, you know that the reason for the failure of bench pressing to enhance arm adduction is that the former is specific to the latter only in the muscles used, not in the way they are used.

What should you do?
So what's the bottom line if you're a runner? You should engage in regular strength training, because scientific studies confirm that it can lower your risk of injury during training and also enhance your running potential, making it easier for you to train with higher quality and run faster races.

However, the strength exercises that most runners utilize - bench presses, squats, power cleans, push presses, biceps curls, sit-ups, calf raises, hamstring curls, and knee extensions - are not specific to the body postures or neuromuscular patterns employed during running and therefore won't help your running very much. It's fine to do such exercises for a little while, in order to enhance your general strength and get used to the idea of strength training. But if you really want to improve your running, you should really focus on resistance exercises that are more specific to the act of running - such as one-leg squats, high-bench step-ups, and one-leg hops in place.

Such exercises are good because they mimic the body postures required for running, but even they have some limitations, especially since force application is still in a vertical plane. Of course, the idea behind strength training for running is ultimately to improve your power in a horizontal direction (most of us don't run upward; we run straight ahead - toward the finish line or toward the end of our workout route).

The more specific your training, the greater the impact training will have on performance. By specializing you will develop the skill needed for your sport and will perform far better than your competitors doing standard training. Specific training will also lead you to some truly amazing personal bests too!

Source: Author, Owen Anderson, www.pponline.co.uk

LONG-TERM EFFECTS OF CREATINE MONOHYDRATE ON STRENGTH AND POWER

The use of creatine monohydrate supplementation by athletes to increase strength and lean body mass has substantial scientific support. There has also been great interest in the use of lower doses of creatine monohydrate for extended periods during heavy resistance training. The purpose of this investigation was to document the long-term effects of creatine monohydrate supplementation on resistance-trained athletes. Sixteen collegiate football players were randomly separated into creatine monohydrate and placebo groups.

Supplementation in capsule form consisted of 5 grams per day of creatine monohydrate or placebo (no loading phase) throughout a 10-week supervised resistance training program. Pretesting and post-testing consisted of the following: weight; body fat estimation; 1 repetition maximum bench press, squat, and power clean; and Cybex testing. Results revealed the creatine monohydrate group was able to significantly increase measures of strength and power and increase body mass without a change in percent body fat, whereas the placebo group showed no significant changes.

The results indicate that 10 weeks of creatine monohydrate supplementation while participating in a resistance training program significantly increases strength and power indices compared with placebo supplementation. These data also indicate that lower doses of creatine monohydrate may be ingested (5 grams per day), without a short-term, large-dose loading phase (20 grams/per day), for an extended period to achieve significant performance enhancement.

Source: The Journal of Strength & Conditioning Research: Vol. 13, No. 3, pp. 187–192.

IS INTENSE EXERCISE HARD ON THE IMMUNE SYSTEM?

Does exercise, help, hurt or have no effect on the immune system? Experts have debated that question over the last few years with no firm answers. Many fitness experts maintain that regular training improves resistance to infections and prevents tumor growth, yet athletes and coaches often report that strenuous training actually seems to produce a higher risk of respiratory infections. Published studies have shown that marathon runners have a much higher than normal chance of developing a cold during the week after a marathon, suggesting that vigorous exercise may open the door for opportunistic pathogens.

The final word on the link between exercise and health is not in yet, but there's now evidence that exercise intensity may be a key factor. Specifically, new research from Denmark suggests that light to moderate exercise boosts immune-system activity, while intense exercise may depress it.

In the Danish research, six healthy individuals exercised on a bicycle for one hour on three different occasions, separated by two-week intervals. In one instance, the subjects cycled at a low intensity of only 25% V02max (just 45-50 per cent of maximal heart rate). On the other occasions they pedaled at either a moderate intensity of 50% V02max (65 per cent of maximal heart rate) or a relatively high intensity of 75% V02max (84 per cent of max heart rate). After each ride, immune-system status was evaluated.

The most dramatic changes in immune-system activity occurred after the high-intensity ride. Blood concentrations of monocytes - a type of white blood cell - were above normal, but the activities of two key types of white cells which destroy invading pathogens - natural killer (NK) cells and Iymphokine-activated killer (LAK) cells - were suppressed following the high-intensity exertions. The Danish researchers suggested that the surplus monocytes which appeared during and after the high-intensity ride released chemicals called prostaglandin’s which inhibited NK- and LAK-cell activity. That's an undesirable response, since immune-system strength declines as NK and LAK activity ebbs.

Meanwhile, concentrations of white blood cells increased during both light and moderate exercise, as did NK cell activity, and there was no suppression of NK cells. The Danish researchers concluded that light and moderate exercise tends to boost the immune system, while intense exercise has some potentially negative effects.

The Danish cyclists were previously untrained, but the strong observed link between hard training or racing and illness suggests that the relationship holds for more experienced athletes, too. It's apparent that sports-active people should consider cutting back on their high intensity training at times when the risk of infection is high (for example, in the winter, when athletes tend to be cooped up with lots of coughing, sniffing people). In addition, when athletes are under increased physical or emotional stress or are getting less rest and sleep than usual, it makes sense for them to temporarily bias their training towards moderate- or low-intensity efforts in order to lower the risk of illness.

Source: www.pponline.co.uk



GOAL-SETTING ALONE IMPROVES PERFORMANCE



A group of 51were grouped to perform a novel task under one of three conditions: public goal-setting, private goal-setting, no goal-setting.

The goals selected, time spent practicing, strategies used during practice, and actual performances were assessed.

Both goal-setting groups performed better than the no-goal control group. The public goal-setting group spent more time practicing, but did not eventually perform any better than the less-practiced private goal-setting group. Baseline (initial) performance levels and the goal set predicted performance best. Practice time, training strategy, and public goal-setting did not account for further performance variance.

These results suggest that goal-setting is beneficial for performing a novel task. However, additional practice did not influence performance. This could be an artifact of the task, the type of subjects, and the fact that the task was novel. Since no attempt was made to evaluate learning rates, the reason for the unexpected lack of influence of extra practice was not forthcoming.

Implication. Setting goals, even when learning novel tasks, produces performance improvements over no goal-setting.