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Using power in specific sport situations

Using power in specific sport situations

It is important to select the most appropriate methods for your chosen sport, for the development and refinement of power, and to allow enough time for the training to take effect. This training phase should last 8-12 weeks – depending on competition needs.

Remember that this type of training is the ‘icing on the cake’ and that it should follow the basic preparation and strength development phases – if maximum sports performance is to accrue.
The components that need to be improved in this phase include the following:

Starting strength – the ability to exert maximal forces instantly, required by a sprinter or field sport athlete, for example.

Explosive strength – the rate at which the player develops force – a requirement of all athletes.

Reactive strength – the combination of eccentric and concentric strength can be measured in the time it takes to reverse direction from an eccentric (braking) contraction to a concentric (accelerating) contraction.


For example, rebound jumps in basketball or volleyball, or foot contacts when sprinting (this is less than 0.9 of a second at elite level). This combination of eccentric – concentric contractions is known as the stretch shortening cycle (SSC) and is the prime element of plyometric training.


What exercises are used?

The exercises used are more dynamic and specific. If the athlete only trained for maximum strength (using heavy weights) then he/she would only be capable of expressing large amounts of force and would not be able to do this quickly (they would not improve their speed of force production).

Being bulky and strong is no guarantee of sporting success (unless you happen to be a sumo wrestler!)


Developing different types of specific sports strength

Starting strength

As in the strength development phase, it is important to use multi-joint dynamic weightlifting exercises that employ triple extension of the joints (ankle, knee, hip). Relevant exercises would include: cleans, snatches, jump squats and lunges. This triple extension is key to numerous sports activities, such as running and jumping.

If the athlete has not learned the (difficult) technique of the Olympic lifts, the next best option is to use the squat and dead-lift exercises, as they are also multi-joint exercises and involve triple extension.

Plyometric exercises – these are highly specific sports power developing exercises. As noted, they develop the stretch/shortening cycle and the explosive power capabilities of muscles. Suitable exercises to improve starting power include: hopping, bounding and depth jumps.

Explosive strength:

As well as weight training, explosive strength can be developed via ballistic exercises, such as medicine ball throws and plyometrics, such as 3 bounds (exaggerated running strides) performed after an 8-10 stride run-up.

Reactive strength:

Reactive strength is trained by using fast explosive jumps, with repeated contacts. For example two-footed jumps over small hurdles, or fast repeated throws against a wall with minimal pause (ground contact).


Plyometric training tips:

It is important that contact with the ground is made, either with the balls of the feet (for vertical jumps) or flat-footed (for horizontal jumps).

Contact with the ground should be light and quick. Time spent with the feet in contact with the ground is time wasted when a player is sprinting or jumping.

How to plan the ‘getting strength to where you need it phase’:

An effective way to schedule power training is to include ballistic and/or plyometric exercises within the same training sessions as weight training. This is variously called, ‘power combination, complex or contrast training’. These work outs have been identified as being particularly useful at targeting and enhancing the power output of fast-twitch muscle fibre (this fibre type contracts 30-70 times a second and is crucial for speed and power). The weight used should be in excess of 70% of 1 repetition maximum (1RM).

This training method, although effective, is also highly intensive, and requires a reduction in the number of exercises performed, and the volume of repetitions per session. This will maintain quality and reduce injury potential, or over-training.

I tend to advocate performing a set of lifts, followed by a set of ballistic/dynamic drills or jumps – this is the ‘contrast’ methodology (the complex one would involve all the sets of one of the pairing of exercises being performed before the other ie all leg presses before the tuck jumps. I recommend a maximum of two sessions of this type of training per week.

It is extremely important to allow adequate rest between sets of lifts and drills, usually 3-5 minutes. Why so much time? The central nervous system (CNS) and energy systems, responsible for generating fast, powerful, movements, fatigue relatively quickly and require sufficient time to recover. Without this amount of recovery time, quality of movement cannot be repeated.

The key to improving explosive power is quality of movement. ‘Less is more’ is a very important proviso for coach and athlete to follow.

The use of speed training in the development of power

For the highly conditioned athlete, performing sprints over short distances is a great way to develop power at this time in the training year – in one session. Its inclusion is highly demanding and should only be used by athletes with at least a couple of years of background of strength conditioning training.

The format for such a session would be:

1) weights

2) plyometrics

3) acceleration sprints.

I would recommend no more than a 300m total volume of acceleration work (specifically of 15-30m sprints) in such a session (10 x 30m sprints, for example).

This ‘triple-whammy session’ is a short-term method for improving power and speed, but it should not become a main feature of the overall training programme. Over-using it will fatigue the athlete, risk injury and lead to diminishing sports performance.

I therefore recommend a three-week period of this type of training – performed twice per week. At the end of the three weeks, I would organise a-week-to-10-day recovery period. A further three-week cycle, followed by another short recovery period, can then be used, if necessary.

Examples of ‘Getting strength to where you need it sessions’

These work outs are based on power combination methods, and combine pairings of weight training and power drill (plyometric) exercises. These pairings work the same muscle groups, suggested reps, and sets and recoveries are provided. These work outs are tough and should only be tackled by the well conditioned.

Note: 1RM refers to one repetition maximum – the maximum amount of weight you could lift once on a particular exercise.
1) Basic level power combination session

Rest: minimal between lifts and power drills – if the athlete has some conditioning background.

Lifts 80% 1RM - 5 reps Power drills - 5 reps Circuits 2-3 Recoveries between Recoveries after each circuit - 5 min
Leg press Tuck jumps 4 min
Bench press Clap (plyo) push-ups 4 min
Squats Standing long jump 4 min


2) Medium-level power combination session

Rest: minimal between paired exercises.

Lifts all 80% 1RM - 5 reps Power drills - 5 reps Circuits 2-3 Recoveries between sets Recoveries after each circuit - 5 min
Power cleans Tuck jumps 4 min
Bench press Medicine ball chest pass against wall 4 min
Squats Depth jumps 4 min

3) Advanced power combination session

Perform sprints after completion of the circuits – see below.

Lifts all 85% 1RM - 4 reps Power drills Circuits 2 Recoveries between sets Recoveries after each circuit - 5 min
Power cleans Hurdle jumps 5 min
Bench press Medicine ball drop and push* 5 min
Split snatch Split jumps 5 min

* This exercise requires the medicine ball to be dropped from another athlete standing over the performer – who is lying on their back. They catch the ball over their chest and immediately throw it back to their partner who catches it. This exercise develops the plyometric response in the chest and arm muscles.

Allow 10-15 min recovery after the last circuit before performing sprints.
Example of sprint session:

2 x 4 x 20m from standing start with two minutes’ rest between each sprint and 10 minutes’ rest between sets.

An option – if the facilities are available – is to perform a set of weight lifts, followed by a power drill set, and then, with minimal recovery, a short sprint. This is only possible if a suitable running surface is situated immediately next to the lifting facility.



This article was taken from the Peak Performance newsletter, the number one source of sports science, training and research. Click here to access these articles as soon as they are released to maximise your performance

Gym exercises to improve swimming performance

Swimmers need to follow a programme of exercises that replicate their actions in the water as closely as possible.

To optimise strength and power, competitive swimmers need to supplement their pool training with land training in the gym. For best effect, swimmers need to follow a programme of exercises that replicate their actions in the water as closely as possible.

Strength and conditioning experts around the world all agree that, for time spent in the gym to have a positive impact on your sports performance, you must ensure the exercises you perform - and the way you perform them - are related to your sporting movements in competition. For example, Barbell Squats involve ankle, knee and hip extensions in a vertical plane which are directly related to the mechanics of a vertical jump; thus the squat is a useful exercise for developing jump performance.

If we perform a basic analysis of the mechanics of the front crawl stroke, the main actions that produce forward propulsion through the water are:

l. the 'arm pull down' through the water, which propels the swimmer forward and

2. the 'leg kick', which alternates hip flexion and extension of the legs.

In addition, competitive swimming involves:
The 'dive start and push off turn', which involves dynamic ankle, knee and hip extension.

When designing your strength programme, you should focus mainly on exercises related to these movements. Other exercises may use the same muscles as those involved in swimming, but only exercises which use the right muscles in a related mechanical movement will provide optimum training benefit.

A limitation of land training with weights for swimming is that the type of resistance you encounter when moving in the water is different from the resistance occurring when you move a weight through the air. In the water, the faster you pull or kick the greater the resistance applied back by the water; on land, a given weight requires a constant force to move it, regardless of the speed of movement.

Hydraulic-type resistance equipment that mimics aquatic resistance is expensive and not widely available. The best compromise when using regular equipment is to try to mimic the speed and nature of the swimming stroke. To this end, you should aim to perform the strength exercises with a smooth and constant force and select weights which allow the movement to be performed at a swimming-related speed. For example, the leg-kicking motion during front crawl is quite fast, so hip flexion and extension exercises which can be performed at a good speed would be best.

The following exercises are related to the mechanics of the front crawl stroke. For each component, the relevant exercises are described and their mechanical relationship to the stroke explained.

Arm pull down exercises

1. Cable rotational front and back pulls

Front pull.

This is the mechanical equivalent to the pulling-through-the-water action in front crawl, as the hand comes diagonally across the body as it pulls down. For this exercise you need a high pulley machine with a simple handle grip.

Kneel down on one knee to the side of the machine. Take the hand nearest the pulley and grasp the handle with the hand high and slightly out to your side. Before you start the exercise make sure your back is straight, your shoulders are wide and your chin is tucked in. Pull the handle down and lower your arm across your body in a rotational movement until your hand is next to the opposite hip. Smoothly return the bar to the start position and continue, performing sets of 5-8 reps for maximum strength or 12-15 for strength endurance.

Try to keep your posture solid throughout the movement. Maintain a slight bend in the elbow as you pull, but focus your effort on the shoulder muscles only.

Rear pull.

This exercise involves the opposite movement to the front pull and is useful for promoting a balanced strength about the shoulder joint. Specifically, the front pull trains the internal rotator cuff muscles and the rear pull trains the external muscles. To avoid shoulder injuries a balanced rotator cuff strength is important. For this exercise you need a low pulley machine with the simple handle grip.

Stand to the side of the machine and grasp the handle with the opposite hand. Make sure your back is straight, your shoulders wide and your chin tucked in. Start with your hand by the inside hip and fix a slight bend in the elbow. Pull the handle up and away from your body, rotating the arm up and out. Finish with the handle high and out to the side, with the palm of the hand facing forwards. Smoothly return the handle back and across to the opposite hip and continue. Again go for sets of 5-8 reps for maximum strength or 12-15 for strength endurance.

Keeping your posture solid during this exercise is quite difficult, as it is tempting to use your trunk muscles to help the rotation movement. However, you can train your core stability skills by keeping your navel pulled into your spine and relaxing your upper body so there are no additional movements apart from the arm raise and rotation.

In combination, the front and rear diagonal pull train almost every muscle in the shoulder joint and shoulder girdle. This makes them very useful exercises for any sport.

2. Medicine ball single arm overhead throw

This exercise develops the power of the latissimus and pectoral muscles in a functional manner for swimmers, involving a movement similar to the front crawl stroke. The aim of the throw is to improve the rate of force development in the shoulder by accelerating the arm hard to throw the ball. For this exercise you need a partner and 2-4kg ball. The small rubber ones are best as they can be held in one hand.

Because the ball is quite heavy for one hand you will not be able to throw it far or move the arm very fast. This makes it ideal for swimming as the pull stroke is not that fast.The training effect comes from your attempts to accelerate the arm movement as fast as you can, thereby improving the power of the pull.

Lie on your back on the floor, with knees bent slightly so your lower back is comfortable. Grasp the ball in one hand with your arm up and behind your head, slightly bent at the elbow. Vigorously pull the arm up and down across your body, throwing the ball over the opposite knee. Get your partner to return the ball, and perform sets of 8-12 repetitions with each arm in turn.

Do not lift your head or pull up from the stomach as you throw. Focus on producing the power from the shoulder and pulling across the body as you do in front crawl.

3. Swiss ball body pulls

This is a 'closed kinetic chain' movement, where the moving limbs remain in contact with a fixed object - in this case the hands with the floor. Such movements are thought to be particularly functional for sports performance, so offering greater training benefits.

This exercise is performed in a horizontal prone position, with the arms pulling down under the body, matching the position and action of a swimmer in the pool.

Position yourself face down, with your lower legs on the Swiss ball and your hands on the floor supporting your weight, body parallel to the floor. This is the equivalent of a press-up position with your feet up. Slowly roll the ball up your legs while your arms extend out in front of you until you achieve a stretched position, with a straight line through your arms, shoulders, back, hips and legs. At this point your body will make a shallow angle with the floor and the ball will be positioned on your thighs. Then, keeping this perfect alignment of your body, push down through your hands into the floor and pull yourself back to the press-up position. The ball should roll back down your legs as you do this. Perform sets of 8-12 repetitions.

The difficult part of the exercise is the pull back up. At this point you must use your stomach muscles to support your spine and focus on using a strong pull of the shoulder muscles to raise your body back to the parallel position. This exercise is not easy, but it is very beneficial for many sports, helping to develop core and shoulder strength.

Leg kick exercises: Hip extension and flexion kick

These exercises mimic the upwards and downwards phases of the swimmer's kick action, where the glutes and hamstrings extend and the hip flexors flex the leg at the hip. For these exercises you need a low pulley machine with an ankle strap attachment. Each leg is worked independently to increase the specificity for swimming, and the weights used should be relatively light so you can kick with good speed, as in the pool.

Hip extension.

Stand facing the low pulley machine, with the ankle strap attached to one leg. Lift this leg off the floor, taking up the slack of the cable, and place your balance solidly on the other leg. Hold onto the machine's frame with your hands to stabilise your upper body and check that your back is straight, with shoulders relaxed.

Pull the cable back dynamically by extending the leg backwards until you feel you need to lean forwards, then bring it back in a controlled manner to the start position, retaining good posture. Continue pulling the leg back, focusing on the gluteals and hamstrings to kick back powerfully.

Hip flexion.

Stand with your back to the low pulley machine, with the ankle strap attached to one leg. Lift this leg off the floor, taking up the slack of the cable, and place your balance solidly on the other leg. Use a stick to support yourself, and check that your back is straight with your shoulders relaxed.

Pull the cable dynamically by kicking the leg forwards. Pull the weight, using your hip flexor muscles at the top and front of the thigh, until your leg reaches an angle of about 30^ or you start to lean back. Smoothly return your leg to the start position, retaining good posture, and continue.

Perform sets of 10 reps at a fast speed and build up to sets of 20 or 30 for power endurance of this movement.

'Dive start and push-off turn' exercise: Barbell squat jumps

This exercise involves dynamic extension of the ankle, knee and hip joints and trains the calf, quadriceps and gluteal muscles to improve vertical jump performance. The vertical jump is mechanically related to the dive start and push-off turns involved in swimming: with the dive or turn, the ankle, knee and hip extension propels you forwards in the horizontal plane, while with the jump the leg extension propels you upwards in the vertical plane. Essentially, it's the same movement rotated by 90û!

The point of using a barbell to add weight to the squat is to help you to generate peak power. If you perform the jump squat with body weight only, the jump will be very fast and high. With the addition of a moderate weight (about 30-40% of the 1 repetition max weight for the squat exercise), the jump will not be as high or fast, but the muscular power required to leave the ground will be maximal. This is based on the knowledge that peak power is achieved when the force used is about one third of the maximum force for that movement. Again, your goal is to attempt to achieve the fastest extension of the legs to maximise power production and training benefit. If you use 30-40% of 1 RM weight, I recommend 3-5 sets of 5 repetitions.

Stand with the barbell across the back of your shoulders. Squat down, bending at the hips and knee, making sure the weight goes down through the back half of your foot. When you reach the half squat position, drive up dynamically, rapidly extending your legs so that you leave the floor briefly. Absorb the landing with soft knees, then go smoothly into the squat again. Continue for 5 repetitions.
The bottom line:

Strength and power training is essential for elite swimming performance.
To optimise the benefit of land-based training, you must select exercises with mechanical relevance to the swimming action, particularly those movements which propel the swimmer through the water, such as the arm pull and leg kick.

As the resistance in the water is different from the resistance provided by weight equipment on land, unless you have special hydraulic equipment, you must also focus on mimicking the speed and smooth movement of the swimming stroke when performing land-based exercises. Various exercises for the arm pull, leg kick, dive and turn movements are suggested, all with a good functional relationship to the swimming action.

While this is not a definitive or exhaustive selection of exercises, especially as it focuses solely on front crawl, it involves highly specific swimming movements in terms of mechanics, positions and speed. When you design strength programmes for swimming performance or any other sport, be sure to think about each exercise in terms of its relevance to performance.

Raphael Brandon

This article was taken from the Peak Performance newsletter, the number one source of sports science, training and research.

Lactate threshold VO2 (LTVO2) and economy to explain 99% of the variance in LT velocity

WHAT REALLY DETERMINES RUNNING PERFORMANCE?
What is the single most important factor that determines running performance?

Is it VO2 max? Not exactly. Is it genetics? Only partly. Is it Power Bars? Not likely. Mental toughness? Well, it helps. Reindeer milk? Bee pollen? Caterpillar fungus? Try again.

Dr. Edward Coyle, of the University of Texas at Austin, knows THE ANSWER. Dr. Coyle has been unravelling the mysteries of endurance performance for 20 years. In a series of 8 studies with runners, cyclists, and race-walkers, Coyle and his colleagues looked at everything from aerobic enzyme activity to gross mechanical efficiency, and how each of these factors contributes to racing speed. In a 1995 paper in Exercise and Sports Science Reviews, Dr. Coyle condensed the results of 2 decades of research into 3 words.

LACTATE THRESHOLD VELOCITY

Lactate threshold velocity? That's right, lactate threshold velocity (LT Velocity) is the single most important determinant of distance running success. In fact, a study with distance runners by Farrell et al. found that over 94% of the variation in racing speed was explained by differences in LT velocity, as compared to only 79% by variation in VO2 max.

So, what exactly is LT velocity?

LT velocity is simply how fast you can run at your lactate threshold. Your LT velocity is directly determined by just 2 factors: your lactate threshold VO2 and your running economy. A study using competitive cyclists found lactate threshold VO2 (LTVO2) and economy to explain 99% of the variance in LT velocity.

LTVO2 is the highest rate at which you can utilize oxygen before lactic acid starts to build-up in your muscles. LTVO2 also happens to be approximately the level of oxygen consumption that you can maintain during a marathon. (Oxygen consumption is measured as milliliters of oxygen consumed per kg of bodyweight per minute.)

To illustrate the advantage of a high LTVO2, say 2 runners have identical VO2 max values of 60 ml/kg/min, but one runner's LTVO2 occurs at 50 ml/kg/min, while the other runner's LTVO2 occurs at 40 ml/kg/min. If the 2 runners try to race the Boston Marathon at a speed that requires 48 ml/kg/min, runner #2 will build-up lactic acid and will have to slow down, and runner #1 will elbow him as she cruises past.

LTVO2 is not the answer by itself, however, because we don't all use the same amount of oxygen at a given speed. Just as some cars are more economical than others in their consumption of gasoline, some runners are more economical than others in their consumption of oxygen. A more economical runner consumes less oxygen to maintain a specific pace.

For example, say 2 runners with identical LTVO2 values of 50 ml/kg/min are racing the Cherry Blossom 10-miler at 6 minutes per mile pace. Sounds like they should both be working equally hard, right? Not necessarily. If runner #1 has an oxygen requirement of 48 ml/kg/min at 6 minute pace, and runner #2 requires 55 ml/kg/min, then runner #1 will be comfortably below LTVO2 and will be able to maintain the pace, but runner #2 will start to accumulate lactic acid and will have to slow down. In this case, runner #1 has a higher LT velocity because she uses her LTVO2 more economically!

What determines LTVO2?

LTVO2 is the highest rate at which you can use oxygen before lactic acid accumulates in your muscles and blood. In a study comparing elite versus good cyclists, Dr. Edward Coyle and colleagues found that 75% of the variation in LTVO2 is explained by VO2 max and aerobic enzyme activity. VO2 max sets the upper limit to your LTVO2, and aerobic enzyme activity and other factors inside the cells determine how close your LTVO2 is to that upper limit.

VO2 max is the maximal amount of oxygen that your cardiovascular system can transport, and which can then be utilized by the working muscles. VO2 max is determined by the amount of blood your heart can pump (the amount of blood pumped per heart-beat times the number of heart-beats), and the amount of oxygen that can be extracted from the blood and used by the muscles.

The good news is that you can increase your VO2 max substantially through training. The bad news for those of us who have been running a long time is that VO2 max tends to increase during the first few years of training but then plateaus.

Since VO2 max plateaus after several years of training, but lactate threshold continues to increase, there must be adaptations occurring inside the muscle cells that allow you to run at a higher percentage of VO2 max without building up lactic acid. The most important adaptation is an increase in aerobic enzyme activity.

Aerobic enzyme activity represents how much energy is being produced aerobically. Aerobic energy production takes place in the cells' mitochondria. Aerobic enzyme activity is determined by the number and size of mitochondria in your muscle cells. Endurance training increases both the number and size of mitochondria, which increases aerobic enzyme activity, which increases LTVO2, which increases LT Velocity, which means you can race faster!

What kinds of workouts will improve LTVO2?

The best way to improve your LTVO2 is to train at your LT Velocity. The problem is, how do you know your LT Velocity? You could go to an exercise physiology lab, and after measuring your lactate at various running speeds, the physiologist could tell you what pace coincides with your lactate threshold. Unfortunately, not many of us have access to a lab. Fortunately, you can estimate your LT Velocity fairly accurately using your race pace for 15K to the 1/2 marathon.

Let's say Alison just ran 70 minutes in the Cherry Blossom 10-Mile Race. To increase her LTVO2, Alison should allocate a portion of her training to running at about 7 minutes per mile. My favorite lactate threshold workout is the classic tempo run popularized by exercise physiologist and coach Jack Daniels in the 1980's. This workout consists of a continuous run of 20-40 minutes at LT Velocity. Alison would warm up, and then do a 3 to 6 mile tempo run at a pace of 7 minutes per mile, followed by a short cooldown jog.

Rather than doing a continuous tempo run, you can gain a similar benefit by breaking the tempo run into 2-4 segments, for a total of 20-40 minutes. For example, 3 repetitions of 10 minutes each at LT Velocity, with a 4-minute jog between reps, will also boost your LTVO2. Low-key races of 5K to 10K make a great substitute for tempo runs. A well-designed schedule would include a tempo run or race 2 out of every 3 weeks. This schedule will improve your lactate threshold, but also help prevent overtraining.

Now we know how to increase LTVO2. So far, we have solved half the puzzle. Next month we will look at what determines your running economy, and how to improve it. For now, get out on the roads and do some tempo runs. Your race times will go down as your lactate threshold VO2 goes up!

(This column originally appeared in Running Times Magazine.)

Is there an optimal training intensity for enhancing the maximal oxygen uptake of distance runners?:

Midgley AW, McNaughton LR, Wilkinson M.

Department of Sport, Health and Exercise Science, University of Hull, Hull, England.

The maximal oxygen uptake (V-dotO(2max)) is considered an important physiological determinant of middle- and long-distance running performance. Little information exists in the scientific literature relating to the most effective training intensity for the enhancement of V-dotO(2max) in well trained distance runners.

Training intensities of 40-50% V-dotO(2max) can increase V-dotO(2max) substantially in untrained individuals. The minimum training intensity that elicits the enhancement of V-dotO(2max) is highly dependent on the initial V-dotO(2max), however, and well trained distance runners probably need to train at relative high percentages of V-dotO(2max) to elicit further increments.

Some authors have suggested that training at 70-80% V-dotO(2max) is optimal. Many studies have investigated the maximum amount of time runners can maintain 95-100% V-dotO(2max) with the assertion that this intensity is optimal in enhancing V-dotO(2max).

Presently, there have been no well controlled training studies to support this premise.

Myocardial morphological changes that increase maximal stroke volume, increased capillarisation of skeletal muscle, increased myoglobin concentration, and increased oxidative capacity of type II skeletal muscle fibres are adaptations associated with the enhancement of V-dotO(2max).

The strength of stimuli that elicit adaptation is exercise intensity dependent up to V-dotO(2max), indicating that training at or near V-dotO(2max) may be the most effective intensity to enhance V-dotO(2max) in well trained distance runners.

Lower training intensities may induce similar adaptation because the physiological stress can be imposed for longer periods. This is probably only true for moderately trained runners, however, because all cardiorespiratory adaptations elicited by submaximal training have probably already been elicited in distance runners competing at a relatively high level.

Well trained distance runners have been reported to reach a plateau in V-dotO(2max) enhancement; however, many studies have demonstrated that the V-dotO(2max) of well trained runners can be enhanced when training protocols known to elicit 95-100% V-dotO(2max) are included in their training programmes.

This supports the premise that high-intensity training may be effective or even necessary for well trained distance runners to enhance V-dotO(2max).

However, the efficacy of optimised protocols for enhancing V-dotO(2max) needs to be established with well controlled studies in which they are compared with protocols involving other training intensities typically used by distance runners to enhance V-dotO(2max).

1: Sports Med. 2006;36(2):117-32.

The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athle

Laursen PB, Jenkins DG.

School of Human Movement Studies, University of Queensland, Brisbane, Australia. plaursen@hms.uq.edu.au

While the physiological adaptations that occur following endurance training in previously sedentary and recreationally active individuals are relatively well understood, the adaptations to training in already highly trained endurance athletes remain unclear.

While significant improvements in endurance performance and corresponding physiological markers are evident following submaximal endurance training in sedentary and recreationally active groups, an additional increase in submaximal training (i.e. volume) in highly trained individuals does not appear to further enhance either endurance performance or associated physiological variables [e.g. peak oxygen uptake (VO2peak), oxidative enzyme activity].

It seems that, for athletes who are already trained, improvements in endurance performance can be achieved only through high-intensity interval training (HIT).

The limited research which has examined changes in muscle enzyme activity in highly trained athletes, following HIT, has revealed no change in oxidative or glycolytic enzyme activity, despite significant improvements in endurance performance (p < 0.05).

Instead, an increase in skeletal muscle buffering capacity may be one mechanism responsible for an improvement in endurance performance.

Changes in plasma volume, stroke volume, as well as muscle cation pumps, myoglobin, capillary density and fibre type characteristics have yet to be investigated in response to HIT with the highly trained athlete. Information relating to HIT programme optimisation in endurance athletes is also very sparse.

Preliminary work using the velocity at which VO2max is achieved (V(max)) as the interval intensity, and fractions (50 to 75%) of the time to exhaustion at V(max) (T(max)) as the interval duration has been successful in eliciting improvements in performance in long-distance runners.

However, V(max) and T(max) have not been used with cyclists. Instead, HIT programme optimisation research in cyclists has revealed that repeated supramaximal sprinting may be equally effective as more traditional HIT programmes for eliciting improvements in endurance performance.

Further examination of the biochemical and physiological adaptations which accompany different HIT programmes, as well as investigation into the optimal HIT programme for eliciting performance enhancements in highly trained athletes is required.

1: Sports Med. 2002;32(1):53-73.

Impact of resistance training on endurance performance. A new form of cross-training?

In accordance with the principles of training specificity, resistance and endurance training induce distinct muscular adaptations.

Endurance training, for example, decreases the activity of the glycolytic enzymes, but increases intramuscular substrate stores, oxidative enzyme activities, and capillary, as well as mitochondrial, density.

In contrast, resistance or strength training reduces mitochondrial density, while marginally impacting capillary density, metabolic enzyme activities and intramuscular substrate stores (except muscle glycogen).

The training modalities do induce one common muscular adaptation: they transform type IIb myofibres into IIa myofibres. This transformation is coupled with opposite changes in fibre size (resistance training increases, and endurance training decreases, fibre size), and, in general, myofibre contractile properties.

As a result of these distinct muscular adaptations, endurance training facilitates aerobic processes, whereas resistance training increases muscular strength and anaerobic power.

Exercise performance data do not fit this paradigm, however, as they indicate that resistance training or the addition of resistance training to an ongoing endurance exercise regimen, including running or cycling, increases both short and long term endurance capacity in sedentary and trained individuals.

Resistance training also appears to improve lactate threshold in untrained individuals during cycling. These improvements may be linked to the capacity of resistance training to alter myofibre size and contractile properties, adaptations that may increase muscular force production.

In contrast to running and cycling, traditional dry land resistance training or combined swim and resistance training does not appear to enhance swimming performance in untrained individuals or competitive swimmers, despite substantially increasing upper body strength.

Combined swim and swim-specific 'in-water' resistance training programmes, however, increase a competitive swimmer's velocity over distances up to 200 m.

Traditional resistance training may be a valuable adjunct to the exercise programmes followed by endurance runners or cyclists, but not swimmers; these latter athletes need more specific forms of resistance training to realise performance improvement.

1: Sports Med. 1998 Mar;25(3):191-200.

Training techniques to improve endurance exercise performances.

Kubukeli ZN, Noakes TD, Dennis SC.

Medical Research Council/University of Cape Town Research Unit on Exercise Science and Sports Medicine, Sports Science Institute of South Africa, Newlands, Cape Town, South Africa. zuko@worldonline.co.za

In previously untrained individuals, endurance training improves peak oxygen uptake (VO2peak), increases capillary density of working muscle, raises blood volume and decreases heart rate during exercise at the same absolute intensity.

In contrast, sprint training has a greater effect on muscle glyco(geno)lytic capacity than on muscle mitochondrial content. Sprint training invariably raises the activity of one or more of the muscle glyco(geno)lytic or related enzymes and enhances sarcolemmal lactate transport capacity.

Some groups have also reported that sprint training transforms muscle fibre types, but these data are conflicting and not supported by any consistent alteration in sarcoplasmic reticulum Ca2+ ATPase activity or muscle physicochemical H+ buffering capacity.

While the adaptations to training have been studied extensively in previously sedentary individuals, far less is known about the responses to high-intensity interval training (HIT) in already highly trained athletes.

Only one group has systematically studied the reported benefits of HIT before competition. They found that >or=6 HIT sessions, was sufficient to maximally increase peak work rate (W(peak)) values and simulated 40 km time-trial (TT(40)) speeds of competitive cyclists by 4 to 5% and 3.0 to 3.5%, respectively.

Maximum 3.0 to 3.5% improvements in TT(40) cycle rides at 75 to 80% of W(peak) after HIT consisting of 4- to 5-minute rides at 80 to 85% of W(peak) supported the idea that athletes should train for competition at exercise intensities specific to their event.

The optimum reduction or 'taper' in intense training to recover from exhaustive exercise before a competition is poorly understood. Most studies have shown that 20 to 80% single-step reductions in training volume over 1 to 4 weeks have little effect on exercise performance, and that it is more important to maintain training intensity than training volume.

Progressive 30 to 75% reductions in pool training volume over 2 to 4 weeks have been shown to improve swimming performances by 2 to 3%. Equally rapid exponential tapers improved 5 km running times by up to 6%.

We found that a 50% single-step reduction in HIT at 70% of W(peak) produced peak approximately 6% improvements in simulated 100 km time-trial performances after 2 weeks.

It is possible that the optimum taper depends on the intensity of the athletes' preceding training and their need to recover from exhaustive exercise to compete. How the optimum duration of a taper is influenced by preceding training intensity and percentage reduction in training volume warrants investigation.

1: Sports Med. 2002;32(8):489-509.

Physiological changes associated with the pre-event taper in athletes.

Mujika I, Padilla S, Pyne D, Busso T.

Department of Research and Development, Medical Services, Athletic Club of Bilbao, Basque Country, Spain. imujika@grn.es

Some of the physiological changes associated with the taper and their relationship with athletic performance are now known.

Since the 1980s a number of studies have examined various physiological responses associated with the cardiorespiratory, metabolic, hormonal, neuromuscular and immunological systems during the pre-event taper across a number of sports.

Changes in the cardiorespiratory system may include an increase in maximal oxygen uptake, but this is not a necessary prerequisite for taper-induced gains in performance.

Oxygen uptake at a given submaximal exercise intensity can decrease during the taper, but this response is more likely to occur in less-skilled athletes.

Resting, maximal and submaximal heart rates do not change, unless athletes show clear signs of overreaching before the taper.

Blood pressure, cardiac dimensions and ventilatory function are generally stable, but submaximal ventilation may decrease.

Possible haematological changes include increased blood and red cell volume, haemoglobin, haematocrit, reticulocytes and haptoglobin, and decreased red cell distribution width. These changes in the taper suggest a positive balance between haemolysis and erythropoiesis, likely to contribute to performance gains.

Metabolic changes during the taper include: a reduced daily energy expenditure; slightly reduced or stable respiratory exchange ratio; increased peak blood lactate concentration; and decreased or unchanged blood lactate at submaximal intensities.

Blood ammonia concentrations show inconsistent trends, muscle glycogen concentration increases progressively and calcium retention mechanisms seem to be triggered during the taper.

Reduced blood creatine kinase concentrations suggest recovery from training stress and muscle damage, but other biochemical markers of training stress and performance capacity are largely unaffected by the taper.

Hormonal markers such as testosterone, cortisol, testosterone : cortisol ratio, 24-hour urinary cortisol : cortisone ratio, plasma and urinary catecholamines, growth hormone and insulin-like growth factor-1 are sometimes affected and changes can correlate with changes in an athlete's performance capacity.

From a neuromuscular perspective, the taper usually results in markedly increased muscular strength and power, often associated with performance gains at the muscular and whole body level. Oxidative enzyme activities can increase, along with positive changes in single muscle fibre size, metabolic properties and contractile properties.

Limited research on the influence of the taper on athletes' immune status indicates that small changes in immune cells, immunoglobulins and cytokines are unlikely to compromise overall immunological protection.

The pre-event taper may also be characterised by psychological changes in the athlete, including a reduction in total mood disturbance and somatic complaints, improved somatic relaxation and self-assessed physical conditioning scores, reduced perception of effort and improved quality of sleep. These changes are often associated with improved post-taper performances.

Mathematical models indicate that the physiological changes associated with the taper are the result of a restoration of previously impaired physiological capacities (fatigue and adaptation model), and the capacity to tolerate training and respond effectively to training undertaken during the taper (variable dose-response model).

Finally, it is important to note that some or all of the described physiological and psychological changes associated with the taper occur simultaneously, which underpins the integrative nature of relationships between these changes and performance enhancement.

1: Sports Med. 2004;34(13):891-927.