Showing posts with label power. Show all posts
Showing posts with label power. Show all posts

Tuesday, 3 February 2009

90 degree press-up

I would like to recommend a website of Dr Barry Drust, a senior Sports Scientist at Liverpool John Moores University who is preparing and training to do a 90-degree push-up. As well as giving great training information he is keeping a personal diary of his training:

http://90degreepressup.wordpress.com/

I think this website is very interesting for those interested in devising their own training programmes.

Thanks

Thursday, 17 January 2008

Which Vibration Platform To Choose?

The fitness regime from outer space has landed! Over the last few years the popularity of vibration-training has increasingly grown with the development of machines such as PowerPlate ™ and Vibrogym ™, and with the recent introduction of personal or ’domestic user’ models, the potential for greater training benefits such as strength and power is now being welcomed into our own homes.

From the current commercially available machines a basic vibration platform can cost as little as £100 while the so-called professional editions will set you back as much as £9000. Generally, much of the differences in cost are accountable to the brand name and design. The type of material used and the quality of construction are undoubtedly important factors for machine performance and durability, however aspects such as choice of colour and sleek design are factors that are unlikely to benefit neither your training results nor your bank balance.

When it comes to choosing a vibration platform it is useful to consider the following factors:

 The operational parameters -
Apart from the type and duration of exercise performed, the intensity of vibration-training depends on the frequency of vibration (the number of oscillations per second, measured in Hertz, Hz) and the amplitude of the oscillatory wave (mm, cm). The higher these characteristics are the greater the mechanical vibration stimulus.

The frequency range of vibration platforms differ with each model. Collectively, the operating range of commercially available machines is around 15Hz to 60Hz. It is typical however, that machines only operate within a limited frequency range; some between 15-30Hz, others between 30-50Hz, and the majority at and around 35Hz ±10Hz, and at specific step increments. Commonly, the amplitude of vibration is a factor that can also be user-determined. Platform vibration amplitude ranges from around 0.5mm to 12mm (peak to peak displacement) depending on the specific machine. When buying a machine it is important to ensure it is capable of operating at the desired vibration intensities.

Most research has centred on 25- 40Hz, but the optimal frequencies for specific training are yet to be determined. While positive effects of WBV have been found at and around 30Hz, there has been little investigation into lower frequency vibration and whether these provide any benefit. Research activity from our department (Mileva et al., 2006) showed that a frequency as low at 10Hz for segmental vibration aided performance during resistance exercise. For whole-body vibration training however, to prevent hitting the resonant frequencies of internal body organs it is advisable that frequencies lower than 20Hz are avoided (Mester et al., 1999)

 The platform dimensions -
Vibration platforms come in a range of sizes. Although machine dimensions are important from a convenience perspective, when choosing a machine it is important to check that the platform area is large enough for performing the type of exercise you require. Performing a deep two-leg squat on a 16 by 12inch platform (as for some low-cost machines) is an exercise feat in itself!

 The type of vibration -
Most commercially available machines such as the PowerPlate ™ and Vibrogym ™ deliver vertical vibrations and as such the platform moves up and down. However, machines are available that deliver rotational vibration based on a pivot-system platform. As would be expected, there is some evidence to suggest that muscular responses to rotational vibration and vertical vibration differ (Abercromby et al., 2007) although both types of vibration have been shown to have beneficial effects for training (see for example Cochrane and Stannard, 2005 and Delecluse et al., 2003).

 User operation -
Some machines come with pre-programmed training regimes with limited flexibility for the user to set their own training programme. If personalisation is required then a machine that allows the user to select parameters such as exercise and rest duration, and number of exercise sets (in addition to the intensity of vibration) should be chosen. Some machines have a limited duration of vibration exposure, so if longer bouts of continuous vibration training are required then the machine capabilities again need to be checked. The majority of vibration-training studies to date have involved less then 10-minutes of continuous vibration training, with many using protocols consisting of approximately 5 sets of 60secs with ~1min rest intervals.

 Medical Device Directive certification -
There are a couple of vibration machines on the current market that have Medical CE Approval. To obtain such certification for a device a company needs to provide proof relating to:
-Safety and electrical compliance
-Risk Management and analysis
-Clear clinical Indications and claims
-Clinical proof of these indications
Although this certificate is not direct evidence for validating a machine, it is worth considering in order to know it is of sound operational function.

 The Extras -
There are many extras that come along with the more costly platforms such as virtual trainer software, connections for peripheral equipment, and even platforms with inbuilt games consoles. If features such as these are not a necessity then there is very little sense in paying extra for machines that offer them.

Hopefully this short-guide to vibration platform basics has provided enough information for you to choose your machine. Whatever your needs, there is likely to be a machine out on the market that suits you. Good luck!

Lisa Zaidell is a scientist at London South Bank University (LSBU) studying the effects of vibration on the human body.

We have many scientists at LSBU researching the various effects of vibration-training. Be sure to check back for our latest research and insights! For the unofficial blog of the LSBU staff please visit www.sportssciencelondon.blogspot.com for information on all aspects of Sports Science and nutrition.

Monday, 17 December 2007

Targeted Vibration Training

Introduction

Vibration stimulation is gaining popularity as a neuromuscular training method with the potential to elicit muscular performance adaptations similar to those produced by explosive strength training. Studies on vibration have shown transient increases in muscle power output and chronic strength enhancement and significantly improved gait and body balance in elderly people. In addition, whole body vibration induced positive adaptations in peripheral blood circulation (increased blood volume and speed of blood flow), probably due to decreased blood viscosity and peripheral resistance and arterial vasodilatation. Additionally, vibration has the potential to activate large amounts of musculature during a movement, and appears to inhibit activation of antagonist muscles which would decrease the braking force during a movement. Other studies have shown that vibration may be able to
influence the excitatory state of the peripheral and central structures of the brain, which could facilitate subsequent voluntary movements.

Targeted Vibration Training

Due to the conflicting results and potential side-effects of whole-body vibration, applying the vibration directly to the exercising muscle only has demonstrated performance gains more than 300% greater than conventional training. Therefore, researchers Dr Mileva and Dr Bowtell hypothesised that vibration applied during a single resistance-training session would promote larger acute increases in strength than those induced by an identical session performed in the absence of vibration. It was further hypothesized that vibration stimulus would provoke a greater response when training at lower contraction intensity, where a smaller percentage of muscle fibers would be voluntarily activated. To accomplish this, researchers compared the acute effects of vibration stimulus during and after high- (70% of one-repetition maximum (1RM) and low intensity (35% 1RM) knee extension exercise.

Methods

Nine healthy male adults completed four trials on a knee extension machine (Technogym UK Ltd) either with (Vibrex, Exoscience Ltd) or without superimposed vibration at low (35% 1RM) and high (70% 1RM) contraction intensities.

Results

The main finding of the study was that vibration applied during knee extension exercise improved the mechanical performance of the quadriceps muscles, as manifested by increased dynamic muscle strength and power. Additionally, peak torque was significantly higher during the vibrated than the nonvibrated trials.

The improvement in strength and power after vibration training could be explained by the finding that the median frequency of the quadriceps muscle electrical activity was significantly higher in the vibrated than nonvibrated trials. This suggests that vibration increases muscle fiber conduction velocity and/or increased recruitment of muscle fibers with faster conduction velocities such as fast powerful muscle fibres.

A very novel finding from this study is that superimposing the vibration-like stimulus during low-intensity exercise simulates the response induced by higher-intensity exercise, evidenced by increased electrical activity in the quadriceps muscle.

The increase in contraction force implies that reflex feedback from the muscle receptors in contracting muscle is increased. One might expect such increases in exercising muscle activation level to elevate the oxygen requirement, and vibration tended to increase the rate of muscle deoxygenation during exercise, which is indicative of increased oxygen utilization.

Conclusions

Neural adaptations are the earliest changes that occur in the exercised muscle (first 3–5 wk of a training
program), permitting gains in strength and power without significant increase in muscle cross-sectional area. The acute enhancement of neuromuscular performance following vibration is probably related to an increase in the sensitivity of the stretch reflex. This would result in more rapid activation and training of a larger number of high-threshold motor units. Vibration-induced discharge of the muscle receptors also recruits previously inactive motor units into the contraction, as well as re-recruiting motor units that are already fatigued, and even increasing their firing patterns.

It is also an intriguing possibility that a chronic vibration training program may potentially increase the neuromuscular adaptations arising from light/moderate training. This would be of importance for individuals, such as the elderly, osteoporosis and rehabilitation where people are unable to complete more intense exercise programs.

Tuesday, 4 December 2007

Breathing vibration - can it make us stronger?

Introduction
Acute vibration stimulation enhances skeletal muscle activity and strength performance (Issurin & Tenenbaum, 1989; Bosco et al., 1999; Mileva et al., 2006). Vibration stimulation has also been applied to the respiratory musculature with demonstrable increases in respiratory activity in rabbits (Jammes et al., 2000), reduced breathlessness at rest in healthy humans (Edo et al., 1998), and reduced breathlessness during exercise in chronic obstructive pulmonary disease patients (Fujie et al., 2002).
We therefore investigated whether a vibration stimulus applied through air as it passes into the airways elicits increments of maximal breathing performance.

Methods
We recruited 12 healthy subjects (8 female, 4 male; 22-50 years old) from the University and they completed 3 maximal inspirations followed by 10 inspirations against a vibration stimulus (VIB; youbreathe, Exoscience Ltd., London, UK), an inspiratory resistive-load training device (RES) or resting breathing (CON; no load). 3 forced inspirations were repeated and compared to pre-training for maximal breathing power.

Results
Maximal breathing power was significantly greater (15%) after 10 breaths of vibrated resistance (VIB) when compared to PRE (VIB) and POST control (CON) and POST resistive-loading training device (RES). There was no effect of either resistance or control breathing on maximal breathing power.

Discussion
10 breaths of vibration lead to increased maximal breathing power suggesting that applying a vibration stimulus increases the voluntary force generating capacity of the inspiratory muscles, in a similar manner observed when vibration is applied to other skeletal muscles (Mileva et al., 2006).
The mechanisms underlying the changes in maximal breathing power require further study, however mechanisms such as shifts in neuromuscular recruitment via increases in stretch reflex sensitivity may have a role (Cardinale, 2003). This would enhance recruitment of higher-threshold motor units and the activation of previously inactive motor units. Confirmation of the mechanisms involved will require the acquisition of respiratory muscle EMG, transcranial magnetic stimulation and testing of peripheral reflexes.
Thus, vibration leads to an increased maximal breathing power suggesting there is an increase in neural inspiratory drive possibly via upregulation of the respiratory motoneurones.

Saturday, 24 November 2007

Fitness for Skiing

It is ski season again and lots of people are doing their best to lose weight and build their fitness ready for the slopes and the après ski. I like everyone else wanted to get in shape for my annual ski trip so this sparked my interest about training for skiing and the resources available on the internet. Actually good resources about fitness for skiing was sparse and terms of quantity and quality. Clearly their are many components to a fitness programme so I will go through what is required including cardiovascular fitness, muscular strength and endurance, power and balance. I will also discuss the relative merits of vibration training, and whether there is any point in adding vibration to your programme. The advice I am going to give today is based on the idea of a 8 week programme (this is way too short but I am a realist).

Cardio fitness

Any activity that involved activity for a long duration, say 6 ours per day for 6 days, is going to require cardiovascular fitness. Add to that the fact that most skiing is done at high altitude, meaning that oxygen will be more scarce, which means that having good cardio health and fitness is an absolute necessity for skiing fitness.

Also having high cardio fitness also means that your powers of recovery will be better from each bout of skiing that you do. This means that you will be more ready to ski again after lunch or as you progress through your holiday.

I would suggest a minimum of 3 cardio sessions per week, probably 1 long slow session for up to 1 hour, 1 short fast session of around 20 mins and even 1 interval session lasting about 30-40 mins. Many of the equipment at gyms these days have interval programmes built in. The interval programmes are also good because they relieve the boredom of training indoors.

Other gadgets you can try are altitude simulation equipment, such as hybreathe (a portable altitude simulator) or one of the many altitude tents available.


Muscular Strength

Strength is an absolute must for skiers, especially novices. Most of your time will be spent climbing off your bottom and it takes a hell of a lot of strength to perform basic turns if technique is not yet perfected. Quad strength is absolutely paramount but also core strength and some upper body strength for using your poles.

Strength is the muscles ability to develop force, which in terms of skiing means lifting more than your normal body weight, often on just 1 leg. You will often be travelling at speed meaning that when you perform turns you will be lifting multiples of your body weight, and before you can actually turn you have to work eccentrically to stop your body from collapsing (I will talk a little bit more about this in the section on vibration training).

To develop strength there is no alternative than to lift heavy weights, close to your maximum with low repetitions – 2 sets of 5 reps is probably ideal. You need to train for strength minimum 2 times per week. The exercises I would include squat or dead lift, bench press, bicep curls and some core exercises front and back. You can supplement with other exercises to keep your training interesting. You can also find machines that incorporate vibration training into your strength by using machines with Vibrex, this technology is very new so might not be available to everyone yet.


Muscular Endurance

Once you have increased your strength it is then time to develop your muscular endurance as when you are skiing it will be for maybe 6 hours per day so being fatigue resistant is important. Muscular endurance is the ability to lift a submaximal force many times. You will be performing turns and stopping repeatedly so this could be the most important part of your programme, we have all felt our legs start to burn when we are only half way down a slope!

To develop muscular endurance ideally you need to lift around 50% of you maximum about 15 times, and I personally would do 3 sets of this per session. Keep the exercises the same as your strength training. As a shortcut you can even put the exercises in a circuit and include this as one of your cardio sessions.


Power

To develop power there seems to be good evidence that this is where vibration platforms can be very useful. Please click here for a PDF document showing different power exercises that can be performed on a platform. I would stick to dynamic squats, dynamic wide stance squats, dynamic one leg squats (this will also help with your balance) and jumping on the platform. As mentioned earlier the vibration platform will also help with eccentric strength, which is the strength you need to stop your body from collapsing especially when performing turns at speed.

When training for power you need to reduce the quantity of sessions you do as it is important your muscles are fresh each time you train. I would train 2 times per week on power.

If you don’t have access to vibration training, then you can use conventional exercises, lifting around 30% of your maximum but the key is to explode through the lift, and try to throw the bar away (obviously it would be good to have some help with this as safety is the most important thing. Lift about 7 reps per set and perform 2 sets of each exercise.


Balance

Everybody forgets about balance but this is one of the most important elements of a skiing programme. The key to good balance is having a strong internal focus. If you keep focussing on things outside your body then you will fall easily. Keep your attention inside your body and you will find your balance improving very quickly. A good place to focus is on your breathing, just behind your tummy. This is a good thing to remember when you are skiing also.

Again the vibration platforms are very good for developing balance for example doing one-leg squats and jumps. Also another vibration related product I cam across is called flexi-bar. This is very good for developing balance and it will help your core also.

Flexibility

Another frequently forgotten element of the ski training programme is flexibility. Good flexibility is important for proper efficient muscle action, and also to enable you to fall with less risk of injury.

After every training session stretch each muscle of your body (especially the ones you have been working) and hold each stretch for at least 20 seconds to develop good flexibility. If you are creative this is a good chance to develop your balance and a strong internal focus.

Breathing Muscle Training

One of the more recent innovations is in breathing muscle training. There are now several devices such as powerlung and powerbreathe. For extra benefit I would recommend a vibration breathing device such as powerbreathe as this can increase growth hormone which can enhance strength and recovery, cardio health as well as training the respiratory system.


Programme Plan

If you have lots of time you can phase your training to make sure you develop each component fully, but if you only have 6-8 weeks left I would recommend 2 cardio sessions per week (1 interval) and 2 circuit sessions per week. In the circuit sessions you can increase muscular strength and endurance whilst also training your cardio fitness.

Enjoy your skiing, see you on the slopes!

Monday, 2 July 2007

Human Growth Hormone continued

Hi,

I am going to continue to talk a little more about human growth hormone responses, but this week I want to talk a little more about breathing. When we designed youbreathe we did so with neuromuscular and hormonal responses in mind. We knew that growth hormone responded very strongly to vibration with exercise, and we knew there were effects of breathing on growth hormone responses. We always had in mind to see if youbreathe would cause growth hormone responses as the theory predicted.

We have some prelim results and it certainly looks promising. We have a couple of elite sprinters and some strength and conditioning coaches trying programmes out with youbreathe use for strength, sprint and power training. All feedback so far has been very positive.

We have several programmes developed so far but we need to continue the research to see which gives the best responses. In the next couple of weeks I will provide here a beta version for you to try in your own training regime. It makes training harder but the potential benefits will be well worth it.

We hope to be able to apply this to many clinical situations were atrophy is a problem and also maybe to obesity.

See you next time

Monday, 25 June 2007

Human Growth Hormone

Hi,

I am going to get back onto my normal thread this week by talking more generally about vibration training. I would like to talk about hormonal responses to vibration training, specifically human growth hormone. Generally there are very conflicting responses to vibration training largely because of the variation in the methods used and protocols followed. But in growth hormone responses the situation seems a lot more clear. Vibration definitely affects growth hormone responses! There still does seem to be some variability in these responses depending upon the muscle chosen to be vibrated, some muscles such as the soleus (which is a more slow type muscle) can cause a depression in growth hormone release.

One point which does seem to clarify this whole situation is that vibration combined with strength training stimulates human growth hormone release more than either vibration or strength training alone. For a long time now I have never thought of vibration training as a replacement for conventional training, but as an adjunct to other forms of training. This info about human growth hormone release seems to support that view, which is bad news for the lazy amongst us.

Also in the treatment of many clinical conditions treatment of artificial growth hormone is prescribed, with signficant side effects, but encouraging the body to produce it's own growth hormone seems a much more sensible and safe idea.

These are the reasons we developed out vibration training solutions such as youbreathe and vibrex which superimpose the vibrations on to traditional exercise. And the results we get are excellent.

OK, I promised you a download for training yourself to perform abdominal breathing, and it is done and tested now.

Please click this link for the training manual.

http://www.youbreathe.com/general/pdf/abdominal%20breathing%20user%20manual.pdf

Thanks

Wednesday, 2 May 2007

This weeks update

We have had a good couple of weeks in terms or research and what we have learnt about vibration. One of our devices has also received great coverage in Athletics Weekly magazine in the week leading up to the marathon. I find it so rewarding when someone comes back with a very positive experience using something that I did or contributed to. This is why we got into Science and this line of research. As a side note the editor of Ultra-Fit (http://www.youbreathe.com/general/images/17-2%20Vibration%20Training.pdf) magazine came back and said youbreathe had really helped him in his rowing time trial performance. These are exciting times indeed.

Many people keep asking me about vibration training and one of the most important questions I keep being asked is do I think it is bad that people are looking for quick fixes rather than doing the hard yards of a conventional training programme. Honestly I agree but what we have to realise is that our society is changing and we have to change with it. People don't seem to have the time to commit to regular training like they used to. So vibration training is one way we can try and keep the world healthy and happy even with a short amount of time and effort.

We also have an exciting week coming up for some of our other vibration inventions. We have a meeting coming up next week with the largest gym equipment manufacturer in the world who want to use our technology for their equipment. I think there hasn't been any major advances in training methods and gym equipment for a good 30 years. Vibration training is a quantum leap forwards for those who embrace it first. I hope soon everyone can have access to a vibration suite based on our technology. That would be fulfilling indeed, especially with the London Olympics coming up.

OK, will keep you updated regarding all things vibration.

Bye