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Intent to Move |
When training for strength and power, athlete should aim to apply as much intent as possible to their movements. By trying to lift weights as explosively as possible, an athlete will accelerate and increase the recruitment of their largest, most powerful type II motor units through the Henneman Size Principle. This higher effort and intent in training in turn increases rate of force development, preferential type II fibre hypertrophy through the SAID principle.Until recently, tracking this intent relied on a keen coaches eye and subjective feedback methods. The ability to track and monitor objective metrics such as velocity and power has become a key coaching tool for providing motivation to athletes, improving training adaptations and reinforcing this higher intent to training. |
The load velocity profile |
In most traditional strength movements, as the amount of load an athlete aims to lift increases, the velocity at which they are able to move decreases. The relationship between load and velocity follow a predictable and consistent linear pattern. The stability of this load velocity relationship has made Velocity Based Training a useful tool to be able to predict and estimate strength levels, fatigue and readiness to train. |
The load power profile |
Similarly to the velocity profile, power and load share a stable relationship, however its shape is a single factor polynomial, with the point of peak power occurring between 30 and 80% of 1RM varying based on the exercise and individual. |
Minimum velocity threshold |
The minimum velocity threshold (MVT) is the slowest velocity at which a repetition can be completed for a given exercise. This value is therefore synonymous with the 1 repetition maximum, a common test and indication of an athletes strength levels and progress in the gym. The MVT has been shown to be consistent for a number of common strength training exercises, although the homogeneity of the research cohorts, variations in lifting technique and differences in velocity values given by different tracking technologies used across exercises may suggest a wider level of individual variation in the minimum velocity values than is currently presented. |
Velocity based training use cases |
Velocity based training has many varied uses and applications in training. While the use of standardised speed zones have been historically popular for the pursuit of specific training qualities, recent research has highlighted that high variations can exist between individuals, and therefore individualisation of load velocity profiling and VBT program design can lead to superior training adaptations. |
Feedback and motivation |
By using velocity as a marker of quality in strength training, coaches and athletes can take this feedback to motivate and compete on these metrics.Two studies showed that providing real-time objective feedback to athletes could lead to instant improvements in jump performance and ultimately greater jump improvements over 6 weeks of training by simply displaying jump performance to the athletes as they completed their repetitions. A further study utilised velocity feedback on the squat exercise in a group of rugby players and showed that those athletes who were exposed to their velocity data during the training session achieved greater improvements in speed and power following the training plan. The addition of an objective target, in this case higher velocity, leads to increases in athlete intrinsic motivation as they pursue personal bests or compete with teammates in the gym environment. This extra motivation can be especially valuable for athletes in certain sports and demographics where strength training can be seen as monotonous. |
Real-time fatigue monitoring |
When strength training, sets with higher repetition ranges lead to higher levels of muscle damage, metabolite build up and greater fatigue effects. This fatigue often presents itself in the form of decreasing velocity across a training set or session. Through the use of velocity monitoring, coaches and athletes can monitor, in real-time, the amount of fatigue that is accumulating as a product of velocity decrement across a set.Velocity stops can be used to limit the amount of velocity loss that is allowed through either a percentage cut off or by setting a limit on how slowly an athlete is allowed to complete a repetition before they must end their set and begin a rest period. A velocity stop of 20% from the fastest repetition is commonly used to help athletes avoid the negative effects of consistent training to failure. Even tighter velocity stops of 5-10% are also common place during tapering or when chasing specific power adaptations. While a velocity loss of 30% and above may have benefits in increasing hypertrophy, this high volume, high fatigue approach to training does also lead to greater type 1 muscle fibre hypertrophy. |
Auto-regulation |
Physical performance levels, also known as readiness, are known to fluctuate wildly on a daily or even hourly basis. Lifestyle stressors, sleep quality, nutrition, hormonal fluctuation and general arousal levels can have a significant impact on strength, power, speed and fitness. These variations can make standardised percentage based training programs difficult to implement and often suboptimal for helping athletes maximise their performance over time.Coaches, sporting organisations and individual athletes typically monitor their daily readiness levels in order to auto-regulate their training loads and volumes. Technologies such as heart rate variability monitoring, GPS data, blood oxygen sensors, along with subjective readiness questionnaires and regular performance testing is used to adjust and calibrate the optimal training stresses on a daily basis.Velocity tracking can be a vital tool in the auto-regulation of training too. As an athlete trains, coaches can receive and analyse training data for their warm up sets, comparing their velocity and power outputs relative to individual testing baselines or recent contextual training data. Drops in velocity relative to normal during these warm up sets can signify fatigue or low readiness to train, prompting intervention and training load adjustments to match this low readiness to train. |
Testing and profiling |
Due to the stable, linear relationship between velocity and load, the load velocity profile can be used to profile an athlete's performance on given exercises over time to track progress and training effectiveness. Many of these testing and profiling scores can be extracted from the standard training process without the need for dedicated testing events. The use of spreadsheet formulas allow coaches to collect these values on a consistent basis to monitor trends in strength and power over time. |
1 Repetition Maximum (1RM). For some of the most common strength training exercises, standardised values have been developed for estimating an athletes maximum strength levels by extending an athletes load velocity profile for a given exercise and finding its intersection with the point of minimum velocity threshold. This value can be calculated using simple spreadsheet calculations and then logged over time. Many studies have found this to be a strongly linked correlation to actual 1RM values. |
Vzero. An alternative metric to the 1RM calculation, Vzero calculates the intersection between the linear load velocity profile and a theoretical velocity of 0 m/s. This can be used as a more general strength tracking value and has better utility for exercises and variations with less reliable 1RM minimum velocity threshold relationships. |
Peak Power. Training at loads that elicit peak power is a common and desirable objective in many sports. Many velocity tracking technologies calculate peak and mean power levels providing values in absolute terms and relative to an athlete's bodyweight. This can then be used to adjust training loads in order to maximise power output on every given rep, optimising the training stimulus on any given training day. Tracking peak power relative to bodyweight can provide valuable insights especially for athletes who may be gaining or losing weight in weight class sports or during off-season periods. |
Velocity based training devices and technology |
There are a range of laboratory based and commercially available technologies that offer a range of features and options for tracking velocity in the gym. |
Lab based 3D motion capture |
Largely considered the gold standard, large multi-camera, high frame rate systems can accurately track and measure movements in 3D space, giving a high precision picture of bar position, bar path, velocity and power metrics. Whilst these systems are incredibly accurate, their cost, size and technical demands in operation make them more suited for academic purposes and have limited application in day to day training for the vast majority gym settings. |
Multi-camera systems |
With advancements in camera precision and processor capacity, 3D motion sensing systems have become more widely adopted through industries such as virtual reality phone applications, video gaming and driving autonomy. |
These same advancements have led to the development of gym and health based velocity and motion tracking systems. These hardware systems are often mounted into a squat rack and programmed to automatically detect and trace athlete movements, providing feedback of movement velocity, range of motion and more. |
Linear Positional Transducers (LPT) |
One of the earliest technologies and still one of the most popular to be used in elite sport, a device containing a rotary encoder and string spool is connected to the training implement, unspooling during movement. As this string uncoils and retracts, it transmits positional data to a digital display or smart device, calculating displacement, velocity and power outputs. |
Linear positional transducers are a valid and reliable method for measuring bar speed and velocity. Some technologies offer X-axis correction to correct for device placement relative to the implement. This offers the ability to measure and display bar path data, while accounting for variance in placement of the device relative to the plane of the movement. |
Smart phone applications |
With recent advances in phone technology, camera quality, and phone computational power, the ability to track movements via computer vision without the need for additional hardware has become more widespread. A number of applications are commercially available at affordable prices and even completely free increasing the accessibility of velocity based training beyond elite and professional sporting contexts. These applications already offer high levels of validity and reliability for bar path, velocity, range of motion, and power metrics. The affordability, easy of use and reliability of the data makes smartphone applications an appealing option for coaches and athletes at every level. |
Accelerometers, IMUs and wearable technology |
Wearable technology incorporating multi-axis accelerometry or inertial motion units (IMU) are common place in a broad range of health and fitness tracking applications. Various commercially available wearable and bar mounted accelerometer devices have been validated to measure and track velocity in real time across a range of exercises. Due to their simpler construction and smaller size compared to positional transducers, these units have had a somewhat wider adoption in the fitness world outside elite sport due to portability, convenience and cost. While they have been found to be reliable and valid, some inconsistency at slow movement speeds along with interference from bar vibration at high speeds can be problematic. |
See also |
Strength and Conditioning Coach |
Strength training |
Power training |
Ballistic training |
Plyometrics |
Sports periodisation |
Weightlifting |
Powerlifting |
CrossFit |
Programming & Periodization |
References |
External links |
Developing Explosive Athletes: Use of Velocity Based Training in Athletes by Dr Bryan Mann: via Google books |
Velocity Based Training by Nunzio Signore via Human Kinetics (international publisher) |
Vine training |
The use of vine training systems in viticulture is aimed primarily to assist in canopy management with finding the balance in enough foliage to facilitate photosynthesis without excessive shading that could impede grape ripening or promote grape diseases. Additional benefits of utilizing particular training systems could be to control potential yields and to facilitate mechanization of certain vineyard tasks such as pruning, irrigation, applying pesticide or fertilizing sprays as well as harvesting the grapes.In deciding on what type of vine training system to use, growers also consider the climate conditions of the vineyard where the amount of sunlight, humidity and wind could have a large impact on the exact benefits the training system offers. For instance, while having a large spread out canopy (such as what the Geneva Double Curtain offers) can promote a favorable leaf to fruit ratio for photosynthesis, it offers very little wind protection. In places such as the Châteauneuf-du-Pape, strong prevailing winds called le mistral can take the fruit right off the vine so a more condensed, protective vine training system is desirable for vineyards there.While closely related, the terms trellising, pruning and vine training are often used interchangeably even though they refer to different things. Technically speaking, the trellis refers to the actual stakes, posts, wires or other structures that the grapevine is attached to. Some vines are allowed to grow free standing without any attachment to a trellising structure. Part of the confusion between trellising and vine training systems stems from the fact that vine training systems will often take on the name of the particular type of trellising involved. Pruning refers to the cutting and shaping of the cordon or "arms" of the grapevine in winter which will determine the number of buds that are allowed to become grape clusters. In some wine regions, such as France, the exact number of buds is outlined by Appellation d'origine contrôlée (AOC) regulations. During the summer growing season, pruning can involve removing young plant shoots or excess bunches of grapes with green harvesting. Vine training systems utilize the practice of trellising and pruning in order to dictate and control a grape vine's canopy which will influence the potential yield of that year's crop as well as the quality of the grapes due to the access of air and sunlight needed for the grapes to ripen fully and for preventing various grape diseases. |
History |
As one of the world's oldest cultivated crops, grapevines have been trained for several millennia. Cultures such as the ancient Egyptians and Phoenicians discovered that different training techniques could promote more abundant and fruitful yields. When the Greeks began to colonize southern Italy in the 8th century BC, they called the land Oenotria which could be interpreted as "staked" or land of staked vines. In the 1st century AD, Roman writers such as Columella and Pliny the Elder gave advice to vineyard owners about what type of vine trainings worked well for certain vineyards.Historically, regional tradition largely dictated what type of vine training would be found in a given area. In the early 20th century, many of these traditions were codified into specific wine laws and regulations such as the French AOC system. The widespread study and utilization of various training systems began in the 1960s when many New World wine regions were developing their wine industry. Without the centuries of tradition that influenced Old World winemaking and viticulture, vine growers in areas like California, Washington, Australia and New Zealand conducted large scale research into how particular vine training systems, pruning and canopy management techniques impacted wine quality. As research in this area continued into the 21st century, new vine training systems were developed that could be adapted to the desired wine making style as well as the labor needs and particular mesoclimate of the vineyard. |
Purpose |
While the most pertinent purpose of establishing a vine training system is canopy management, especially dealing with shading, there are many other reasons that come into play. As members of the Vitis family, grapevines are climbing plants that do not have their own natural support like trees. While grapevines have woody trunks, the weight of a vine's leafy canopy and grape clusters will often bring the vine's cordons or "arms" down towards the ground unless it receives some form of support.In viticulture, growers want to avoid any part of the cordon from touching the ground because of the vine's natural inclination to send out suckers or basal shoots and take root in that area where the cordon is touching the ground. Ever since the phylloxera epidemic of the 19th century, many vines are grafted on phylloxera-resistant rootstock. However, the "top part" of the grafted vine is still very susceptible to the phylloxera, and should a part of that vine take root both the daughter and the original mother vine will risk being infected by the louse. Additionally this daughter vine will leech resources of water and nutrients from the mother vine which can diminish the quality of both vines' grape production.Other reasons for vine training involve setting up the vineyard and each individual vine canopy for more efficient labor usage or mechanization. Vines that are trained to have their "fruiting zone" of grape clusters at waist to chest height are easier for vineyard workers to harvest without straining their bodies with excessive bending or reaching. Similarly, keeping the fruiting zone in a consistent spot on each vine makes it easier to set up machinery for pruning, spraying and harvesting. |
The impact of excessive shading |
Many vine training systems are designed to avoid excessive shading of the fruit by the leafy growth (the "canopy"). While some shading is beneficial, especially in very hot and sunny climates, to prevent heat stress, excessive amounts of shading can have negative impact on grape development. As a photosynthetic plant, grapevines need access to sunlight in order to complete their physiological processes. Through photosynthesis, less than 10% of the full sunlight received by a leaf is converted into energy which makes obstacles such as shading even more detrimental to the plant. Even if the leaves at the top of the canopy are receiving plenty of sunlight, the young buds, grape clusters and leaves below will still experience some negative impact. During the annual growth cycle of the grapevine, excessive shading can reduce the success rate of bud formation, budbreak, fruit set as well as the size and quantity of grape berries on a cluster.The grape clusters receive some benefit from receiving direct sunlight through enhanced ripening of various phenolic compounds that can contribute to a wine's aroma and quality. In addition to having decreased physiological ripeness, excessive shade will negatively impact a grape's quality by causing increases in the levels of potassium, malic acid and pH in the grapes while decreasing the amount of sugar, tartaric acid and color producing anthocyanins. Beyond a lack of sunlight, excessive shading limits the amount of air circulation that can take place within a vine's canopy. In wet, humid climates poor air circulation can promote the development of various grape diseases such as powdery mildew and grey rot. |
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