Archive for July, 2010

Join the Resistance Part II

Posted in Sports science, Training tips
Thursday, July 22nd, 2010


push-up-med-ball.jpgIt’s important to note that all of the test programmes and exercises cited in the preceding article did not involve sport specific movements. As such the link between endurance sports and resistance training is not clear cut. If we use a runner as an example with multiple joint actions and numerous muscle groups requires the various actions to work together to maintain control and balance where standard weight training only focus on a particular muscle group in a constant plane of motion. For example leg extensions will make ones quadriceps stronger however the strength gain is not specific to the way the quadriceps are activated while running and is not weight bearing. One could suggest this type of training is like coaching rugby players individually on their own position and without practicing together as a team expecting them to play in sync.

Resistance exercises aimed at improving running performance should not just attempt to increase general muscle strength; they should enhance specific activities of the nervous and muscular systems which promote faster, more coordinated movements (3).

While free weights are much more sport specific than machines integrated actions in medicine ball work, plyometric and kettlebell training can offer use for certain sports (8). It is also important that sport specific movements do not interfere with technique when the movements are similar but not identical (8) furthermore strength exercises of high force at low velocity do not provide benefits for sports requiring acceleration and vice-versa (8,2).

Plyometric Training

Plyometrics are any exercise that helps to develop the stretch shortening cycle of a muscle (4). They start with the stretching of a muscle, an amortisation phase (the period of time from the beginning of the lengthening phase to the beginning of the take-off phase) and then a muscle contraction phase (4). In this sense the faster the stretching phase, the faster the contraction phase. Such exercises can include jumping, bounding or throwing. During the early part of an athletes career the aforementioned exercises can be improved simply by increasing strength, however once maximal strength is reached one must increase their explosive strength or power to improve (4), hence the reason for plyometric training. One study in particular found that the greatest gains from plyometric training came from professional/elite athletes than amateur athletes (4). In this sense plyometric training should only typically be conducted after years of strength training, furthermore those highly trained athletes who failed to benefit from high resistance work should implement plyometric training.

 Kettlebell Training

 

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Join the Resistance - Part I

Posted in Adventure racing, Multisport, Sports science
Thursday, July 22nd, 2010


med-ball-lunge-home.jpgThe application of resistance training largely comes down to the individual. Do you to fit into the ectomorph slot (those with low muscle mass levels)? If so, you are going to be likely more suited to plyometric and strength based work, whereas if you fit into the mesomorph slot (those with high muscle mass levels) you may be more suited to postural/core and proprioception exercises.

Your work:life balance, access to facilities and resources as well as your budget and personality will influence how much and what type of resistance training is prescribed as will your age and resistance training experience.

Muscle Mass

Bigger, stronger muscles generate more forceful contractions which produce higher power and greater speed (1). However big muscles use more of our limited energy stores which is not compatible with the demands of endurance sport.

Other important findings to keep in mind when shaping a resistance training program:

  • High peak power – endurance races are typically performed at a constant speed and peak power often secondary is important as powering over short hills attacking quickly will make your race more successful (1). Excellent for races like the coast to coast run where direction and terrain changes constantly.

  • Lower relative muscular effort – Movements require a given force by the muscles, when your muscular strength is increased less of your maximal force is required to make the movement, increasing your muscular endurance (1).

  • Reduced injury risk – Stronger muscles are more capable of withstanding injury producing forces (1).

In effect, high muscle mass is useful in sports which are of shorter duration, require frequent intense bursts of power and where body weight is largely supported (1). For example a multisports race dominated by cycling and running will require limited strength, however if this race finishes with a technical and short kayak upper body and core strength training could provide an advantage. Interestingly some sports, particularly cycling will construct optimal power to weight ratios for climbers and power to height ratios for time trial specialists (1). Muscle mass is critical for performance of all endurance athletes however the importance is deciding how much time you will devote to it given your particular sport, event or individual physiology.

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Salomon XT Wings trail shoes review

Posted in Adventure racing, Multisport, Orienteering, Product reviews, Trail running
Tuesday, July 6th, 2010


salomon-xt-wings-shoes.jpgI have tried all sorts of shoes for multisports racing and training, be it a specific trail shoe for the coast to coast or a general road shoe for laps round the park. Most of these race shoes last a couple of hard mountain runs while the more durable lack the feel for technical running and white road shoes say “I’m a triathlete” a little much for style points in the off-road scene. The Salomon XT Wings seem to fit the bill, they are durable, perform well in technical situations and look uber cool with some jeans for your après MTB at the local.

After extensive testing in the Port Hills, the streets of Sao Paolo and numerous jungle trails in Brazil my verdict is on the Wings; piece by piece:

Uppers

Quick drying mesh and sensibly integrated textile parts. Practically, there is nothing more annoying than the uppers of a new shoe shredding quickly because the mesh is as weak as tissue paper and lets out water while letting in gravel. The XT Wings upper design obviates this.

Protection

The rubber belt offers an ideal blend of flexibility and protection. Shoes with super tough protection plates sound great but typically render the shoe hopeless for technical trails, further more they restrict the foots natural movement. When you lack feel for the trail, efficiency of movement is compromised.

The rubber toe cap provides enough protection for all but the biggest hits without adding excessive weight. (more…)

VO2 MAX & interval training

Posted in Sports science, Training tips
Tuesday, July 6th, 2010


What is VO2max again?

The amount of oxygen(milliliters) you can use in one minute per kilo of body weight is the individuals VO2max or the highest rate of oxygen consumption attainable during maximal or exhaustive exercise(2). An athlete who is fit will have higher a VO2max than an untrained athlete at higher exercise intensities (3). As an athlete increases their exercise intensity their oxygen consumption increases until it reaches its maximum capacity. It is this point where VO2max is reached, however it is important to note that the exercise intensity can still increase however without further oxygen uptake (3). It is important to note that VO2max on its own is an inappropriate predictor of athletic performance (2,3) however it does provide a indication of athletic potential where lactate threshold will provide a better indication of athletic performance relative to the individuals ability (2).

Factors affecting VO2max

Genetic endowment contributes largely to ones VO2max due to the body’s ability to either utilize available oxygen or deliver oxygen to active tissues.

Utilization Theory

Maintains that VO2max is determined by the body’s ability to utilize the available oxygen. In effect, VO2max is limited by a lack of sufficient oxidative enzymes within the cell’s mitochondria (2).

Presentation Theory

Maintains that it’s the ability of the body’s cardio-vascular system to deliver oxygen to active tissues that is the key determinant, VO2max depends on increased blood volume, maximal cardiac output and better perfusion of blood into the muscles (2).

While both theories have their role in determining VO2max it is concluded that oxygen supply is the major influence in determining endurance performance as only weak relationships exist between oxidative enzymes and increase in VO2max (2).

Age

VO2max decreases with age, at an average rate of decline of 1% every year after age 25 and is typically attributed due to the effects of aging on the cardio-vascular system (2).

Intensive training during younger years does not offset this process, actually elite athletes have shown a more rapid decline (1.5% per year) once their careers are finished (2). This is not all doom and gloom, conversely master athletes show only minor loss (0.5-0.6% per year) while maintaining the same relative intensity of training (2).

Interval Length/Rate of Recovery and VO2max

vVO2max is the velocity at VO2max. When work intervals are conducted below vVO2max the total load on the cardio-vascular system can be directly related to the length of the work interval (1). On a study of work intervals over 30 seconds, 1 minute, 2 minutes, 3 minutes all carried out at moderately high but not high vVO2max intensities it was found that the shortest intervals produced sub maximal load on the circulatory and respiratory systems as well as low lactate levels (1). From this we must suggest intervals lower than vVO2max are more appropriate as the lactate production and elimination should be trained for longer endurance events and maximum speed at vVO2max is not as necessary as for a 5 kilometer runner.

In using the longer intervals VO2max will be attained in the first interval and subsequent recovery intervals will need less time to depress oxygen usage. Why? When moving at less than 90% vVO2max but above 90% of vVO2max it takes roughly two minutes.

From a practical point of view one should decrease work intervals during the session instead of increasing recovery interval as this will decrease average oxygen consumption rates and mean levels of lactate production effects which are counter productive in terms of VO2max and lactate threshold (1).

If VO2max or lactate threshold are unimportant and you only want to improve running economy the recovery to work ratio should be high(1) e.g. a 400m runner with little need for lactate threshold and aerobic capacity would have short work intervals and long recovery intervals to increase economy and speed.

Importance of vVO2max and Interval Progression

Long intervals can produce problems as they may display a false positive. Athletes with high vVO2 will be able to run quickly at VO2max, hence is fairly efficient making vVO2max a good indicator of performance (1). For example an athlete with excellent economy (running speed) may have a poor VO2max and is unable to reach high speeds at VO2max (1), a vital attribute for racing.

French researcher Veronique Billat has suggested the best way to convert interval training into performance increases is utilize vVO2max efforts in training to improve vVO2max, VO2max and lactate threshold and economy (1). While this training may cause lactate threshold to remain consistent the velocity at lactate threshold will increase due to improvements of vVO2max, furthermore training at vVO2max increases strength and power, strength boosts economy as when muscle fibers are stronger fewer are recruited to move at similar paces (1).

Ofcourse for the majority of athletes performing 3 minute intervals at vVO2max is not attainable from the get go; they need to build up to such an intensive session.

Billat suggests the use of 30 seconds at 100% vVO2max followed by 30 seconds at 50% of vVO2max. Interestingly even when the 30-30 is performed till exhaustion (when vVO2max cannot be sustained for 30 seconds) it is still less taxing than 5 x 3minutes at vVO2max (1). This 30-30 session can then progress to a 60-60 at which point one can begin training the classic 5 x 3 minutes at vVO2max.

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