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James de Lacey Strength & Conditioning
Saturday, 12 March 2016
Saturday, 2 January 2016
Squat More To Sprint Faster?
We've all been told that if we
want to sprint faster, we need to get stronger and squat more. But is this
really the case?
A 2012 study of
the 100-meter sprint involved nine physical education students, three national
level sprinters and one world class sprinter. Since this review is focused on
short sprint speed, only the 4-second distance was measured. The researchers
found significant, strong correlations between the index of force application
(the direction force is applied), horizontal GRF (ground reaction force in the
horizontal direction) and the 4-second distance. However, no significant
correlations were found between vertical GRF and 4-second distance. Average and
maximal power output were also significantly correlated with 4-second distance.
This was further backed up by a
2014 study. Sprint performances of 10 meters and 40
meters were measured comparing elite rugby league backs and forwards. Backs
were found to be significantly faster than forwards in both sprints; however,
there were no significant differences in vertical force or sprint mechanics.
Significant differences in relative horizontal force and relative power were
found between forwards and backs.
Another recent 2015 study looked at elite (international level)
and sub-elite (French national level) sprinters over 40 meters. The researchers
found the horizontal propulsive force to be significantly correlated with
40-meter sprint performance. In contrast, vertical force was not correlated
with sprint acceleration performance. More importantly, there was a tendency
towards a negative correlation between vertical force and 40-meter sprint
performance.
What does this all mean?
The data suggests that when it
comes to short sprint performance, the direction in which force and power
are applied (horizontal direction) is more important than the magnitude (how
much) of force and power produced overall. Moreover, athletes who can "push"
more in the horizontal direction are faster. In addition, producing more
vertical force over horizontal force during your sprint (i.e., accelerating
with a very upright posture orientating force more vertically while sprinting),
may negatively impact your 40-meter sprint performance.
Practical Applications
Here are a few exercises you can
implement in your training to develop horizontal capabilities to improve short
sprint speed, which is a vital performance attribute in many team and
individual sports.
- Heavy Sled Drag or Prowler Push
- Heavy 45-Degree Back Extension (specifically
45 degrees as the angle where torque is greatest at the hips better
represents the acceleration phase of sprinting than the 90-degree back
extension).
- Kettlebell Swing
- Glute Bridge and Hip Thrust (all variations)
- Broad Jump and Broad Jump with Handheld
Loading
- Bounding
- Medicine Ball Forward Scoop Toss
In this post here, I give examples of contrast pairings you
can use in your training to enhance both horizontal force and power capability.
References:
Morin, JB, Bourdin, M, Edouard, P,
Peyrot, N, Samozino, P, and Lacour, JR. "Mechanical determinants of 100-m
sprint running performance." Eur J Appl Physiol, 112:
3921-3930, 2012.
Morin, JB, Slawinski, J, Dorel, S,
Saez de villareal, E, Couturier, A, Samozino, P, Brughelli, M, and Rabita, G.
"Acceleration capability in elite sprinters and ground impulse: Push more,
brake less?" J Biomechanics,2015.
Sunday, 18 October 2015
A Different Approach for Endurance Training to Prepare Athletes for Competition: Team & Combat Sports Prep Part 2
Summing up from part
1, performing 1 week of 5 HIT sessions followed by 3 weeks of 1 HIT session a
week with a general focus on low intensity training resulted in superior
adaptations in VO2max,
Wmax and power output at 2mmol/L of blood lactate compared with
4 weeks of 2 weekly HIT sessions interspersed with low intensity training.
Below I will discuss some practical implications of the research reviewed in
part 1. The ideas below are just potential ways of implementing this way of
organising training and every idea put forth may not present the same results
as the study reviewed as team and combat sports have many other components to
train than just a big aerobic tank.
Someone's happy their aerobic conditioning paid off
My sport
involves me being powerful, why should I spend so much time and effort
developing my aerobic system?
The importance of developing a very large and powerful aerobic system
for team or combat sports may have been underrated over the years with the idea
of trying to create a powerful athlete. It is important to note an
improved lactate threshold (shown in the study in part 1 from improvement in
power output at 2mmol/L lactate) from this organisation of training means you
have less reliance on the anaerobic system (a good thing!!) allowing your well-developed
aerobic system to supply most of your energy. This means you can sustain your
power outputs throughout games and rounds and be less likely to gas out. For
example, being able to throw harder punches for longer or being able to run
faster for longer. Furthermore, you will be able to recover faster between
explosive efforts (punching, kicking, sprinting, tackling) meaning you
can perform more work (e.g. repeated sprint) and recover faster between rounds
or halves of play.
How could I use this
for team sports during pre-season?
Potentially this schedule of training could be implemented in many, non-pure
endurance based sports such as team sports. A rugby or soccer preseason may be
a good place to implement this block periodisation. For examples sake, an 8
week preseason could potentially run a 5 HIT per week on weeks 1 and week 5
which frees up a lot of time in the subsequent weeks for tough technical
training. During weeks 1 and 5 in this instance, volume of every other facet of
training would have to be reduced but the following 3 weeks would potentially
allow you to get many good quality training sessions which are either technical
or strength/speed work.
Tackling by CSM Bucuresti, example of a high intensity effort
Could I use this
during the in-season?
I think where this organisation of aerobic training really has its
merits is the week or 2 before a finals playoff series. This would lead well into
3 or 4 weeks of finals play as a lot of the heavy aerobic work is done allowing
training between matches to be recovery and technical focused along with gym
work. However, usually there is no break between the last game of the round and
the first week of finals play so the last round game would have to have no
bearing on your finals play. In addition to this, a higher risk of injury may
be present due to the lowered perceived well-being of the legs as observed in
the Ronnestad et al., (2014) study. This could be offset by supplementing some
running and cycling sessions with less lower body intensive training such as
swimming or grinder.
If your team is really lacking aerobically during the season, then this
could be implemented during a bye week but I feel this idea is really only
beneficial if your preseason was well below average (e.g. couldn’t train very
often etc). If anything, it may be detrimental to try this during a bye week,
not in terms of aerobic adaptations but in terms of its impact on fatigue
during a long season of weekly matches.
Not sure this applies to Ronda since her fights only last 14sec...
What about
combat sports?
In my opinion, combat sports may best benefit from this style of organising
aerobic training. This is because gassing out in a combat sport has very different consequences to gassing out in a team sport. One involves potentially losing, the other involves losing and potentially finding yourself in hospital. Usually, camps leading to a fight are 8 weeks. So similar to
the rugby preseason example above, weeks 1 and 5 would involve 5 HIT sessions.
The rest of the weeks would allow technical sessions to be the main focus
leading up to the fight. Furthermore, it would allow you to taper well into the
fight relieving any fatigue going in.
Overall, there are a few ways of implementing block perioidisation for
aerobic development in non, pure endurance based sports. There is no one best
way of organising training and the way you organise yours or your teams
training is going to depend on the strengths and weaknesses of your squad/athlete,
the time you have and the facilities available.
Monday, 28 September 2015
A Different Approach for Endurance Training to Prepare Athletes for Competition: Block vs Traditional Periodization Part 1
A couple of recent studies have looked into Block
Periodization (BP) vs Traditional Periodization (TRAD) when it comes to
endurance training in well trained endurance athletes (Ronnestad et al., 2014
& 2015). The major physiological determinants of endurance performance are
work economy, lactate threshold and VO2max. To improve these 3
qualities, a mixture of low and high intensity training should be performed
(e.g. extensive endurance training: 40-120mins @50-60% maximal aerobic speed or 65-75% HRmax; and
high intensity training: 4mins @100% MAS). However, it still remains unclear how
to organise low intensity training and HIT to achieve optimal performance
improvements.
Block periodization (championed by Vladimir Issurin) has
been theorised as an effective way to organise endurance training. Block
periodization refers to focusing on a few select abilities over a short
training block (1-4 weeks) while maintaining other abilities. An example of
this would be heavily developing the aerobic system (cardio endurance) while
maintaining the alactic system (used for short bursts up to around 10sec). In
contrast, traditional periodization looks to develop multiple abilities at once
which according to Issurin, leads to suboptimal adaptations in well trained
athletes.
In this post, I will just look at Ronnestad et al., (2014)
where the authors look to compare a BP model with TRAD periodization in regards
to endurance training and leave the 2015 for a separate post. Both papers show
similar findings in 2 different endurance athlete populations.
Who were the subjects
and how were they grouped?
19 well trained male cyclists were assigned to either the BP
or TRAD based on their VO2max. BP cyclists had 6 ± 4 years of
competitive experience and had a self-reported 9 ± 3h per week of low intensity
training with no HIT in the 2 months lead up prior to this study. TRAD cyclists
had 6 ± 4 years of competitive experience and had a self-reported 10 ± 3 per
week of low intensity training with no HIT in the 2 months lead up prior to the
study.
How was the
intervention organised and how long was it?
Both groups performed the same volume of both HIT and low
intensity training over the 4 week intervention. Endurance training was divided
into 3 HR zones: 1) 60-82%; 2) 83-87%; 3) 88-100% of HRmax. HIT sessions
alternated between 6x5 and 5x6mins in the zone 3 intensity with 2.5-3mins rest
between intervals. Riders were instructed to perform each HIT session with the
aim to produce the highest possible mean power output across the intervals
which was used as an indicator of performance. BP group performed a 1 week block of 5 HIT sessions followed by 3 weeks
of 1 HIT session with a naturally high volume of low intensity training. TRAD group performed 2 HIT sessions per week
throughout the intervention period, interspersed with a relatively high
volume of low intensity training.
Illustration of time and volume spent in each zone
What was measured
pre, post and during the intervention?
Cyclists reported their perceived well-being in the legs on
a 9-point scale, going from very very good to very very heavy after each
training week. Pre and post intervention, cyclists performed submaximal and
maximal incremental cycling tests to gain; VO2max, Wmax
(mean power output during last 2mins of maximal incremental test) and power
output at 2mmol/L. There were no significant differences between the groups
before the intervention in regards to these variables. I have left a few
measures out just to keep this short and less complicated.
What it's like performing the incremental tests
What were the
findings?
The BP group
significantly increased their VO2max, Wmax and power
output at 2mmol/L of blood lactate while no changes occurred in the TRAD group.
Wmax increased 2.1 ±
2.8% (P< 0.05) and VO2max by 4.6 ± 3.7% (P< 0.05) with
moderate to large effect sizes (ES = 0.85 & 1.34 respectively). Power
output at 2mmol/L improved 10 ± 12% (P< 0.05) with a moderate effect size
(ES = 0.71). Perceived well-being in the legs was significantly lower in the BP
group during the 1st week of intervention compared with TRAD.
However, BP reported improved well-being in the legs during the following 3
weeks (P< 0.05).
Summing up
Performing 1 week of 5 HIT sessions followed by 3 weeks of 1
HIT session a week with a general focus on low intensity training resulted in superior adaptations compared with 4
weeks of 2 weekly HIT sessions interspersed with low intensity training. A BP
approach could potentially be a better way of preparing for an endurance event
than the TRAD approach, especially if preparation time is short.
In the next installment, I will discuss these results a
little further and run through some practical applications for sports that are
not pure endurance sports such as team and combat sports.
References
Wednesday, 23 September 2015
Rugby Union vs League. Who’s faster and why?
You may have always wondered which rugby code has the best
athletes. Fanatics of each side will always choose their favoured code of the
two but now we can take a scientific view. While this won’t give the whole
picture as to who are better athletes, we can look into one important facet of performance
being speed. With the NRL finals and the Rugby World Cup currently underway, this
is a good time to compare both rugby codes.
This recent study by Cross et al., (2015) may give some
insight into our question of who’s faster.
NOTE: This data is only a sample of the elite rugby union
and league population.
Who were the
subjects?
15 elite rugby union and 15 elite rugby league athletes were
tested in this study. These were athletes from the New Zealand All Blacks and
the New Zealand Warriors NRL squads respectively. Of the Warriors squad; 7 have represented New Zealand, 5 have represented Tonga, 1 has represented Australia, 1 has represented the Cook Islands and 1 has represented Samoa. Hence both groups of union and league athletes being classed as elite.
What was measured and
how?
Forwards performed 20m sprints while backs performed 30m
sprints. Athlete characteristics (age, height, mass) were recorded between
forwards and backs. Sprinting data was collected through a radar gun system
(similar to a police speed gun). From the radar system, the authors were able
to measure; Vmax (max velocity), v0 (theoretical maximum velocity), vopt
(velocity at peak power production), relative Pmax (peak power relative to body
mass), relative F0 (theoretical maximum force relative to body mass) and
relative Fopt (force at peak power relative to body mass). In
addition to this, split times were able to be measured and were at 2, 5, 10, 20
and 30m splits. Some of these variables are explained in my overshoot
phenomenon series HERE.
So what were the
results?
The only difference in anthropometry was rugby union
forwards being moderately heavier than their league counterparts (ES = 1.01). Differences
in split times between rugby codes for forwards were unclear for all distances,
however rugby union backs demonstrated moderately
faster times at all split distances compared to league backs (2m; ES =
0.95, 5m; ES = 0.86. 10m; ES = 0.76, 20m; ES = 0.76, 30m; ES = 0.63). Distance
covered by rugby union backs at 2 seconds (ES = 0.75) and 4 seconds (ES = 0.70)
was moderately greater than their
league counterparts. In addition, rugby union backs displayed moderately
greater relative horizontal force (F0), power (Pmax) and greater force produced
at peak power (Fopt). Differences in velocity were unclear.
What can we take from
these findings?
The most interesting finding in my opinion is that while
forwards between codes displayed unclear differences in all of the variables
above, they were on average 7.5kg (6.7%) heavier than rugby league forwards. This
means that union forwards are able to
accelerate and reach velocities similar to league forwards while producing
higher amounts of force (ES = 0.77) due to their greater body mass.
Effectively, forwards are able to generate greater momentum (momentum = mass x
velocity) than league forwards essentially giving them greater ability to break
tackles. The authors attributed this difference to the positional demands of
rugby union forwards as they have to overcome a greater number of high force
movements such as scrums, rucks and mauls which favour athletes who can
effectively accelerate their own body mass.
The authors looked further into the acceleration differences
between backs. They determined that the increased acceleration seen by union
backs would mean at 2sec and 4sec of the sprint they would possibly be 0.44m
and 0.73m ahead of their league counterparts respectively. The authors further ascertain
that short sprint performance in elite rugby appears to be related to
horizontal force and power and speculate that acceleration capabilities would
benefit from a more force dominant force/velocity
profile.
Rugby Union wins this
one
Based on the data presented in this study by Cross et al., (2015),
rugby union backs are faster over 30m than their league counterparts. Furthermore,
while there were no differences between forwards in short sprint performance,
union forwards were 6.7% heavier allowing them to possess greater momentum. A
force dominant force/velocity profile seems to be advantageous to short sprint
performance (i.e. being really strong in the horizontal direction). This post
HERE will give you some ideas on exercises to improve short sprint performance.
Reference
Thursday, 27 August 2015
The First 10m the Most Important for Short Sprint Performance in Sport?
If you’ve ever played a
team field sport, I’m sure you’ve heard the saying the first 10m of the sprint
is the most important when making a fast action play such as chasing after a
ball or someone or making a line break. But is there any research out there to
back this up?
A new study has been
recently published last month (July 2015) by Morin and colleagues. It is titled
“Acceleration capability in elite sprinters and ground impulse: Push more,
brake less?” This paper may help us gain a better understanding into short
sprint performance and the saying “the first 10m is the most important.”
So what did the
researchers have the subjects do?
7 sprints were performed
per subject (2x10m, 2x15m, 20m, 30m and 40m) with 4mins rest between sprints.
How was the data
collected and what was collected?
A 6.6m force platform was
used in an indoor track. Vertical, horizontal and mediolateral ground reaction
force were measured using this device. Within this, backward orientation of the
horizontal force vector (braking impulse IMPh-) and forward
orientation of the horizontal force vector (propulsive impulse IMPh+).
You may be wondering how a 6m force platform could measure variables over a 40m
sprint. Well starting blocks started over the platform for the first 10m sprint
and the starting blocks were placed further and further back from the force
platform for each subsequent sprint (15-40m). In doing so, the researchers were
able to create a “virtual” 40m acceleration getting data from foot contacts
over the full 40m distance.
What were the
characteristics of the subjects?
9 elite (international
level) or sub-elite (French national level) male sprinters with personal best
100m times ranging from 9.95-10.60sec. As stated by the authors, the range of
performances is not that narrow hence the findings of this study may not only
apply to just high level sprinters.
What are some of the
relevant findings and what do they mean?
40m sprint performance
was significantly correlated to high values of overall horizontal force.
However, IMPh+ was siginicantly positively correlated with 40m
sprint performance while IMPh- was not. The result of this shows IMPh+
to be the key factor in 40m sprint performance. In layman’s terms, the faster athletes are the ones
that “push” more in the horizontal directon.
Another important finding
was that vertical force was not correlated to sprint acceleration performance
and more importantly, there was a non-significant tendency towards a negative
correlation between vertical force and 40m performance. Meaning, if you are
producing more vertical force over horizontal force during your sprint (i.e.
accelerating with a very upright posture orientating force more vertically
while sprinting), you may negatively impact your 40m sprint performance.
Finally, 40m values were
correlated with the first 0-20m and the second 20-40m part of the sprint. The
correlations were similar as above when correlating the values with the first
20m. However, no correlations were found over the second section of the sprint
(20-40m). This indicates that much
of the 40m sprint performance is determined by how much horizontal force is
produced over the first 20m, with as much IMPh+ (push) as possible.
Summing up
So it seems that
statement of “the first 10m being the most important” may be true and have some scientific
backing. This study suggests that the first 0-20m of the sprint is the most
important in regards to these mechanical variables for short sprint performance. In order to have a fast first 20m, according to this research an athlete needs
to be able to produce high amounts of horizontal force relative to body mass
with minimal force being produced in the vertical force vector. There is
potential for these findings to guide training for field sport athletes such as
soccer or rugby where short sprint speed is vital to performance.
Practical Application
One simple way to train
this attribute is the use of heavy sled drags. This will make you closer to
parallel to the ground and will force you to “push” in the horizontal
direction. I have listed some other exercises in a previous post HERE.
References
Sunday, 16 August 2015
Horizontal Exercise Combo
A little exercise combo to help develop horizontal force and velocity capabilities we used at Olimpia CSM Bucuresti Rugby.
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