Category: Training Theory

Try Sprint Interval Training To Improve Your Running Performance

You have been hitting the trails, logging miles and doing everything that you are supposed to in order to improve your endurance and power.  Maybe you have a race coming up in a few weeks or you just want the personal accomplishment of getting through your regular run a little bit faster.  If you are finding that despite all your worthwhile efforts your performance has not changed in a meaningful way perhaps it is time to consider integrating sprint interval training into your program.

This week we take a look at an interesting study that shows a way for well trained individuals to really move the needle on their running performance with a minimal amount of time spent training.  As we go through the study keep in mind three things.  First, this study was conducted with subjects who were already well trained athletes.  We would expect to see positive changes in studies that take subjects who aren’t active and put them on aerobic/endurance/power based training plans.  If you are starting from a low level of fitness and get on a regular, supervised program most people will see a change for the better.  Taking a group of well trained athletes and coaxing a meaningful change in their performance is much more difficult and demonstrates the power of the training intervention.

Second, this study was done in a real world setting, not in a laboratory.  Often the changes that can be achieved in a very controlled setting working on a treadmill or cycle ergometer cannot be replicated in quite the same way in a real world setting.  If you cannot go out to the track, trail, road or gym and achieve the benefit of the specific plan studied then it might not matter all that much that it can produce an effect in the laboratory.

Third, this study achieved meaningful results with just a two week intervention.  Often we need data over much longer periods of time, weeks, months, even years to determine the impact of a particular intervention.  In the case of this study part of what was so interesting is that the trained athletes used as subjects achieved the beneficial effects of the sprint interval training program in just two weeks.  Who doesn’t want to do something that will improve their performance in such a short period of time?

The Study

In this study running performance was measured with a 3,000 meter time trial and a run timed to exhaustion at 90% of maximal aerobic speed (MAS).  The training program consisted of three workouts per week for two weeks.  In each workout the sprint intervals were 30 second all-out shuttle runs followed by 4 minutes of rest.  The subjects performed 4 rounds in their first workout, 5 rounds in their second, 6 rounds in their third and fourth workout, 7 rounds in their fifth workout and dropped down to 4 rounds in their sixth workout.

The total sprinting time over the two weeks totaled 16 minutes.  The entire 6 sessions only took 110 minutes including the rest time.  The shortest workout was 14 minutes and the longest was only 27.5 minutes.

To conduct the actual sprints, cones were placed every 5 meters for a 30 meter distance.  During the sprints the subjects would run to the 5m cone and back, then the 10m cone and back and so on until they reached the 30m distance.  They would continue running at full speed until the 30 seconds were up.

Three additional variables were also measured for each session.  1) The subjects peak power, which was considered the longest distance they ran in a 30-second period.  2) Mean power which was the total distance they ran for the session divided by the number of sets they ran that workout.  3) Fatigue index was considered the difference between the longest sprint they ran in any given workout and the shortest sprint they ran in the same workout.

Results

Maximal aerobic speed saw a 2.8% increase.  This was significant though the effect size was small.  For the timed run at 90% of maximal aerobic speed there was a 42% improvement (158.9 seconds) which was considered a large effect size.  The timed 3,000 meter run saw a decrease of 50.4 seconds which is a 5.7% improvement in time.  The effect size is considered small-to-medium.

Peak power had a 2.4% improvement (3.06 m), significant but a small-to-medium effect size.  Mean power had a significant 2.9% improvement (13.9 m) for a medium effect size.  The fatigue index showed a positive trend with a medium effect size thought it did not reach a level of statistical significance.

Putting It All Together

So what does this all mean for most runners out there?  First and most importantly it shows that a very short 2-week low volume program can produce significant improvements in performance.  Most competitive runners already have fairly lengthy training programs and a schedule of competitions to plan around.  Even if you are not a competitive runner odds are that you still have a limited amount of time to train and are still interested in improving your performance.  A simple low volume, high-intensity program like this can quickly make positive improvements in both endurance and anaerobic performance.  Additionally this study demonstrates that the improvements are not limited to untrained subjects that will respond to just about any regular training protocol, already highly trained subjects can make significant improvements with this type of training.

Secondly a program like this does not require any special equipment.  A few cones make it look pretty but some water bottles, t-shirts, a big rock all work equally as well.  It is always nice to have a new training technique that doesn’t require you to open your wallet.  This study clearly showed that the results can be achieved in a real world setting without highly calibrated expensive laboratory equipment.

Third, all you need is a clear 30 meter space to run your sprints.  This means it can be done almost anywhere.  Even if you don’t have a full 30 meters you could still follow the program and simply limit the longest available distance to 20 or 25 meters.  Even if you have to train indoors because of weather it is still simple to perform a program like this.

Fourth, it is easy for multiple athletes to perform this program at the same time.  Individuals can set up right next to each other.  This makes it ideal for those working with teams to put everyone through the program together.  There is the added benefit that running against others often motivates people to push even harder.

A program similar to this can also be used as a tapering plan allowing for high intensities and low volumes to be programmed as you get closer to competition.

So why does such a short duration, low volume program produce such good results?  The leading theory is that this high intensity training technique leads to increases in enzymatic activity in both the aerobic and anaerobic energy systems.  It is also possible that this approach improved neuromuscular capacity which can result in improved running economy.

The use of shuttle runs was an interesting choice of the authors.  It allowed for high intensity training while ensuring that the improvements seen in the actual tests were not the result of skill acquisition but due to physiological adaptations.  As previously mentioned it also allowed for a small space to be utilized and a competitive atmosphere to be established between subjects.    This leads to the question of if another form of sprint interval training could produce similar results?  There is probably nothing magical about the use of shuttle runs in and of themselves.  The high intensity that they stimulate is most likely the key factor so it would not be reaching too far to assume that if the same intensity can be maintained for a full 30 seconds on a longer sprint, similar results would probably be achievable.  This eliminates the advantage of only needing a small space along with some of the mental variety that shuttle runs introduce but coaches shouldn’t feel limited to only using that one approach to including high intensity sprint intervals.

It would be interesting to compare the results of this study to slightly different training protocols. What would happen if you used a time different then 30 seconds for the sprints?  Do you need to go all the way up to 7 sets or can similar results be achieved if the volume is kept lower and only 4 or 5 intervals are used?  Would more intervals produce greater results or what happens if the program if followed for more than 2 weeks?  Like all studies, this one could had to choose a particular set of variables to use but the positive outcomes they produced makes you want to explore how those variables can be tweaked to produce even greater outcomes or optimize the time actually committed to the program.

There you go.  If you are looking for a way to improve running performance but do not have hours to commit over a prolonged period of time now you have a technique that will allow you to turbo-charge your training with a simple to perform, short duration low volume sprint interval plan.  Who doesn’t want to see a 42% improvement in their paced running and a 5.7% improvement in their race time for such a small amount of training?

Koral, J., Oranchuk, D., Herrera, R. and Millet, G. (2018) Six Sessions Of Sprint Interval Training Improves Running Performance In Trained Athletes.  Journal of Strength and Conditioning Research. 32(3): 617-623.

Which Strength Exercise Maximally Works Your Glutes And Hamstrings: Hip Thrust, Barbell Deadlift or Hex Bar Deadlift?

Whether you are an athlete concerned about maximizing performance or focused on how you look everyone wants to pick the most effective exercises.  You’ve only got so much time in the gym and a limited amount of energy.  No one wants to waste either one when results are the name of the game.  We know what the most commonly chosen exercises are for any given movement pattern and body part.  That is no mystery, however once those choices are narrowed downed it can become more difficult to decide exactly which movement to go with.

When it comes to lower body exercises that work the glutes and hamstrings three of the most common and successful choices are the barbell deadlift, the hex bar deadlift and the barbell hip thrust.  All three are frequently used and excellent exercises.  While they are not the only movements used train hip extension and to target muscle activation of the posterior chain they are extremely popular choices because all three allow heavy weights to be used which force significant amounts of muscle recruitment.  We know how the game works, the more muscle you can recruit, the more strength and muscle you can develop.

Today we are looking at a just published electromyographic (EMG) study that compares muscle activation in the gluteus maximus, bicep femoris and erector spinae during the barbell deadlift, hex bar deadlift and hip thrust.  Measurements were taken during 1 repetition maximum efforts.  While the gluteus maximus and bicep femoris are not the on the only glute and hamstring muscles that contribute to hip extension, they are the largest components of their muscle groups and superficially located allowing for easy and more accurate EMG readings.  Their individual activation is extremely relevant regarding their movement patterns and contributions to developing maximal strength, power and athletic performance.

On all three movements muscle activation measurements were take for the entire range of motion as well as separated into the upper half of the movement and the lower half.  Measurements were only taken for the concentric, lifting portion of the movements.

For gluteus maximus activation the hip thrust was clearly the winner.  When looking at the entire range of motion the hip thrust had 8% more activation then the barbell deadlift and 16% more activation then the hex deadlift.  Neither of those values reached statistical significance but they are notable.  When looking at the upper portion of the movement the hip thrust showed 13% more activation then the barbell and 26% more than the hex bar.  The difference on the upper portion of the movement between the hip thrust and hex bar was significant.    When comparing the barbell and hex bar deadlifts there were no significant differences though the trend was in favor of the barbell deadlift showing more activation.

Bicep femoris activation showed a different trend that clearly favored the barbell deadlift.  For the entire movement the barbell deadlift showed a significant difference of 20% more activation then the hip thrust and 28% more than the hex bar deadlift.  When looking at only the lower portion of the movements the barbell deadlift was clearly more effective then the hex bar and had a very significant 48% more activation then the hip thrust.  For the upper portion of the movement the barbell deadlift continued to be the leader with a 39% advantage over the hex bar.  What was interesting is that despite the hex bar showing more activation then the hip thrust for the lower portion of the movement , on the upper portion of the movement the hip thrust had 34% more bicep femoris activity then the hex bar deadlift.  Clearly biomechanical changes throughout the movements alter the muscle activation.

On all three lifts and in all three conditions erector spinae activation was similar and showed no significant differences or major trends.

Applications And Limitations

This study pretty clearly shows that for maximum muscle activation of the gluteus maximus the hip thrust is way to go.  For maximum bicep femoris activity then the barbell deadlift should be the main choice.  While that information is great to know and can certainly direct program design decisions, you shouldn’t walk around thinking that you shouldn’t do barbell or hex bar deadlifts for glutes or that you always need to choose barbell deadlifts over hex deadlifts or hip thrusts for hamstring involvement.  All three movements still work both muscles groups significantly.  Both muscle groups are significantly involved in hip extension and all three are still effective choices for hip extension loading.

The differences seen in the upper versus lower portions of the movement suggest that if you are training for a sport you might need to think more specifically about unique biomechanical demands of that sport.  How much bend is there at the knee or what is the hip/torso position when you need maximum muscle recruitment and power?  We saw more hamstring utilization in the lower portion of the hex bar deadlift but more in the upper portion of the hip thrust.  If you have to choose only one to do which one more closely resembles the specific demands of the sport you are training for?

There are also other considerations that may come into play in choosing exercises besides maximum muscle activation.  Many individuals have some history of low back injury and depending on what type of pathology they have, the loads that are placed on spinal disks and other structures may be an over-riding factor in exercise selection.  The back is a longer lever arm in the barbell deadlift as compared to the hex bar deadlift.  Even though the hex bar showed lower muscle activation levels, being able to align the load closer to the center of the body and enabling the lifter to find a more upright torso position may make the hex bar a far superior choice for many individuals.  I frequently choose to use the hex bar over the barbell for clients that can deadlift but I have concerns over how I am loading their low backs and their individual capabilities to find the correct body positions to protect themselves.

This study was also done with 1 repetition maximum lifts which are generally associated with maximum strength.  While we can expect to see similar results with higher repetition ranges and sub-maximal loads or with different speeds of movement this study does not look at those variables.  There may be differences that need to be teased out in future studies.

This study does not look at quadriceps activation.  When choosing a deadlift variation you may be concerned with how the quadriceps contribute to the movement and want more or less involvement from them.  There are also potential issues relating to the height of the bench used in the hip thrust.  A lower or higher bench could alter maximal muscle activation depending on the height and limb lengths of the lifter.  There are also potential differences with populations.  This study was done with a small number of experienced males.  There could be differences with other populations.

Despite the limitations of this study and the other factors that need to be taken into considering when selecting an exercise this study is quite interesting and provides some useful data to help direct our programming.  Now get out there and do some heavy deadlifts and hip thrusts.

Andersen, V., Fimland, M., Mo, D-A., Iversen, V., Vederhus, T., Hellebo, L, Nordaune, K. and Saeterbakken, A. (2018) Electromyographic Comparison Of Barbell Deadlift, Hex Bar Deadlift, And Hip Thrust Exercises: A Cross-Over Study.  Journal of Strength and Conditioning Research. 32(3):587-593