Running with foxes

I have now completed 10 weeks of the first 12 week training block in my three year campaign to prepare myself for a marathon in the autumn of 2012.  It is too early for a quantitative evaluation of this first block, but nonetheless, it is possible to begin to formulate some initial impressions and to begin to explore the question of what modifications I will make to my plans in the next training block. 

The specific goal of the first block has been to increase my leg muscle strength and power in order to recover some of the stride length that I have lost with the passing years.  At present, when I sprint my cadence rises to around 245 steps per minute but my stride length scarcely exceeds 1.5m.  This certainly reflects a loss of leg strength with age, and is almost certainly inefficient.  In addition to the goal of increasing strength and power, increasing my aerobic fitness is a background goal that will be on the agenda for the entire three year campaign.

I have been following a program that includes specific leg strengthening sessions, mainly using body-weight resistance exercises; sprinting and uphill strides; together with a weekly longish run in the low aerobic zone and two tempo sessions on the elliptical cross trainer.  I had described the program in slightly greater detail in my posting on 13th December.

The first question in assessing progress is how closely I have followed the intended program. I had set myself the target of completing at least 90% of the specified sessions.  In fact I have achieved 100% of the specified sessions, so far, and in addition, have managed to do a few extra low or mid-aerobic running sessions.   However, despite doing slightly more sessions than intended, I have been near the limit of what my body is currently fit enough to handle. 

Approximately 50% of the sessions are quite demanding, and on several occasions I had to decrease the intensity of sessions to limit the accumulation of fatigue.  The first occasion was near the end of the first month, when increasing tiredness led me to make a 10% reduction in target power-output during the elliptical sessions.  After this small reduction in intensity, I coped well for the second month.  Then, over the Christmas period, I added a few additional running sessions, and subsequently, at the beginning of the current week, my legs felt very heavy.

Ice and snow

The icy conditions of the past two weeks have also contributed to the challenge.  A high pressure zone located over central Europe has deflected the westerly breezes that normally bring us moisture and warmth from the Atlantic at this time of the year.  Instead a chilly north-easterly sub-arctic air-stream has delivered the iciest few weeks that Britain has experienced for several decades.  In the east midlands we have has less snow than other parts of Britain, but nonetheless, intermittent desultory snow falls have left the ground with a thin and somewhat treacherous coating of ice.  When running, the first challenge has been to remain upright.  High cadence and short time on stance have been essential.

On Tuesday evening when I arrived home from work, it was snowing properly; large soft flakes were covering everything with a beguiling white blanket.  It was too good an opportunity to miss so I slipped on my trainers and headed out for a run.  Although it was already about 4 hours since the sun had set, the snow was reflecting every iota of residual light, so I headed for the riverside path below the escarpment.  No signs of human habitation were ether visible or audible, but I suspect that it was reflected light from the village beyond the escarpment that filtered through the trees to light my way.  There were fresh fox tracks on the path, and after about 800m I caught up with the fox.  We looked at each other quizzically for a few moments.  Despite the low light level, he looked splendid with his russet fur contrasted against the white snow.  Then he trotted off through the trees and I continued on my way.   I returned home feeling mentally refreshed but aware that my legs were very tired after the increased training volume in the previous week.

By midweek, my heart rate was 3-8 bpm higher for a particular workload on the elliptical cross trainer, indicating that I was becoming over-stressed.  Rather than decrease the intensity of sessions on this occasion, I shortened the sessions by about 25%.   On Saturday (yesterday) my energy level was back to normal when I set out for my weekly sprinting session, at the end of an easy 10Km low-aerobic run.  Unfortunately, on account of the depth of snow cover, my pace could scarcely be called sprinting.  My peak pace was only 3:10 min/Km (compared with my more usual 2:40 min/Km in recent weeks).  Indeed 3:10 min/Km is similar to my 10K pace of 40 years ago.  My cadence was 240 steps per minute, indicating that my stride length was only 1.3 m. Almost certainly the deep snow was holding me too long on stance. It was a session more likely to develop leg strength than good neuromuscular coordination.  Nonetheless I felt invigorated.     

Today I did 4x200m uphill strides and then an easy 15 Km run.  Again the conditions underfoot slowed me, but the air temperature continued to be invigorating.  When I turned directly into the chilly northeasterly breeze after about 8Km, I could feel the sweat on my brow begin to freeze; the wind-driven snow was nipping my exposed wrists and my fingers went numb inside my gloves. It was a relief to turn back southwards with the wind behind me for the final few Km.   I have been taking heart beats per Km during aerobic runs as an index of aerobic fitness, and have typically been recording around 640 b/Km in recent weeks, but today the recording was 720 b/Km. I suspect that was mainly due to diversion of blood to my innards to keep my core temperature up.  Although my pace was slow, I actually felt quite strong.

So, in the past few weeks, the snow and ice have prevented any meaningful quantitative assessment of my fitness, but I am pleased that I am feeling stronger.  Although running in the snow has provided some enchanting moments, I hope it has cleared in two weeks time when I am scheduled to repeat the various tests of leg strength and aerobic fitness to evaluate the outcome of this 12 week training block.

Leg strength and power

Despite the moderate evidence of gains in leg strength revealed by the mid-block tests reported on 13th December, the continuing shortness of my stride leads me to anticipate that I will have to devote further sessions to increasing my leg strength and power.   Following the mid-block tests I had decided to persist with the body-weight resistance exercises and to introduce a small amount of low intensity plyometrics into the weekly schedule.  I have done this, but do not expect to see much evidence of gain from the low intensity exercises done so far. I am regarding this as preparation for the next phase.  At this stage I anticipate that building leg strength will continue to be a major focus of the next three month block. 

My provisional plan will be to continue with twice weekly resistance sessions, one session focused on the legs, the other on core strength.  I will almost certainly augment the body weight exercises with exercises employing greater resistance.  I am quite impressed by the potential value of resistance work with stretch cords.  It appears to me that the sustained resistance provided by cords minimizes the risk of jerky movements that might occur with free weights.

I will also include 2 or 3 brief session of about 20 minutes each week in which I will do low to medium intensity plyometrics; other explosive exercises; and running-specific drills.  The low intensity plyometrics will include exercises such as line jumps (jumping forward and back over a line with a focus on quick movement with minimal time on the ground) and two-footed jumps over very low hurdles.  By doing these jumps with two feet, each leg is required to lift only half my body weight and I am able to get off stance very rapidly – much more rapidly than when hopping or when running.   I hope this will encourage efficient co-ordination between the stretch receptors in my tendons and the motor neurons in the spinal cord that are responsible for initiating muscular contraction.

My medium term plan formulated in November includes preparation for a 10 Km race in the spring.  Provided my legs can cope with the demands I will be making of them, I will gradually replace the current elliptical interval and tempo sessions with interval running sessions.  However I am mindful of the fact that during the current training block, there have been times when my legs have become tired and heavy, so I will reserve the possibility of continuing to do the interval sessions on the elliptical cross trainer, where the absence of eccentric stress extracts a lesser price from my legs muscles while allowing aerobic development.

22 Responses to “Running with foxes”

  1. Ewen Says:

    You seem to be coping well with the icy blasts from the north. We have quite the reverse – 38C today. Interesting about the beats/km being elevated because of the cold. Mine are also elevated, but because of blood going to the skin for cooling I guess.

    I’ll be interested if you get some quantitative data on stride improvement. I feel mine has improved by doing the drills and short hill sprints – I put the 7 sec improvement in the 1500 down to that, as I haven’t done any interval work yet.

    I notice you’ve adjusted some sessions because of fatigue – are you still using HRV as an indication of overtraining?

  2. RICK Says:

    Cantute I think a side on video of you running at say 10k and also mile pace would give you a very good evaluation of your stride and what is needed to improve it.
    reading Peter Coe’s books makes me think you might be able to gain a few cm or more through improved ankle dorsa flexon and improved flexability in your hips.
    Oh and well done Ewen:]

  3. canute1 Says:

    Well done in the 1500m.

    With regard to the higher b/Km in the cold, I suspect that both the drag of the snow and the need to keep my core temperature up were responsible – and I agree that your higher b/KM in the heat is probably due to greater blood flow to the surface. So b/Km is only reliable under fairly consistent conditions.

    With regard to regular assessment of training stress, I have not been doing the orthostatic test regularly simply because it takes about 10 min each morning and I my current time budget does not allow it. However, I get a fairly good estimate of autonomic status from my frequent elliptical sessions – which are done under consistent conditions. HR at a steady power output of 100 watts is remarkably consistent from day to day provided I am not stressed, and therefore provides a good marker of sympathetic tone. At a constant power output of 175 watts, the amount of high frequency fluctuation (indicating parasympathetic function ) is similarly consistent but increases after several exhausting days, which I think is a sign that my parasympathetic system is acting more vigorously to protect my heart – so I take things a bit more easily the next day.
    So for the time being I am happy to use these two measures, though I will return to a more detailed consideration of this issue in the future.

  4. canute1 Says:

    Thanks for those suggestions. I have been doing hip swings regularly for quite some time – in an attempt to maintain reasonable hip flexibility. I was amused by that amazing photo in the newspapers a week or so ago, of President Zuma celebrating marriage to his third wife. He was in full tribal regalia doing a spectacular hip swing. He was not getting his ankle quite as high as I can manage – though I think he is actually a year or two older than me – and his regalia was definitely far more splendid than my running kit, so I can understand why the photo editors from the newspapers were impressed.

  5. canute1 Says:

    Since you posted your comment suggesting that I might improve my stride length by improving ankle dorsiflexion I have been pondering what you (and Peter Coe) considered to be the role of ankle dorsiflexion in increasing stride length. In addition to examining my own foot dynamics and thinking, I have also re-read some of Coe’s writings.

    The first point to make is that one should distinguish dorsiflexion during swing phase from that during stance. Let’s start with stance. Dorsiflexion occurs in early stance. Although each movement that occurs during stance contributes to the integrated action that gets us airborne and initiates the swing of the leg, I do not think ankle dorsiflexion during stance plays major role in determining stride length.

    The dorsiflexion in ealry stance is well illustrated by the photos of Julianne Henner (US representative in the 1500m in the Barcelona Olympics) in fig 1.5a and 1.5b of Martin and Coe’s book ‘Better Training for Distance Runners’. Julianne is a midfoot striker, and in fig 1.5a is shown landing with her heel barely off the ground. I land a little further forward and suspect I have the weigth a little more toward the ball of the foot in accord with the recommendation of Al Lyman in your comment on my Dec 31st posting. However, in both Julianne (and I believe, in myself) the dorsiflexion results in the heel touching down by midstance (as shown in fig 1.5b). This touch-down of the heel is the action that I had described in my caveat regarding Al Lyman’s description, and which led JonP to become a little angry with me because it is contrary the Pose emphasis on keeping the weight on the ball of the foot. In fact there is no consensus among experts in biomechanics regarding how much load should be borne by the heel. However, my own belief is that at least for distance runners it is helpful to allow the heel to bear a small amount of weight so that load is distributed along the longitudinal arch at midstance. That touch down of the heel is achieved by a passive dorsiflexion of the ankle.

    But for the present discussion, the question is: does this dorsiflexion play any role in increased stride length? I think the plantar flexion in late stance plays a much larger role in promoting the upwards and forwards push required for an adequate stride length. Understanding the mechanism of this plantar flexion presents an interesting challenge. The crucial thing is probably the release of stored elastic energy that lifts the heel of the ground, and produces supination at the sub-talar joint, locking the midtarsal joint to produce a firm lever that propels the foot up and forwards. To the extent that the elastic energy had been stored during the period of dorsiflexion, one might describe the period of dorsiflexion as relevant. However, I think it is the ability of both the quads and the hamstrings together with the soleus and gastrocnemius, to sustain a powerful eccentric contraction at footfall that achieves the storage of elastic energy. So, I am left with the conclusion that strengthening these muscles is a major requirement for ensuring adequate stride length. Almost certainly plyometric hops and jumps are the most efficient, but also the most risky, way to achieve this.

    The issue I am less clear about is the role of dorsiflexion during swing. Because there is plantar flexion in late stance, it will be necessary to reverse this after lift off. If there is dorsiflexion immediately after lift off, gastrocnemius will be tensed and, because gastrocnemius cross the knee joint, this will promote efficient flexion of the knee joint to bring the foot up behind the buttocks. I suspect this is important for a sprinter, though for a distance runner, perhaps less so. If dorsiflexion of the ankle is maintained in the final stage of swing, the gastrocnemius will be under tension at footfall and this will promote storage of elastic energy. However, unless the flexion of the knee at footfall is substantial, dorsiflexion of the ankle at this point will result in heel striking. So I think that ankle dorsiflexion prior to footfall would only be feasible for a midfoot or forefoot runner if there is a substantial paw-back. I regard a deliberate paw-back as a useful thing for a sprinter, but I am less sure about its role for a distance runner. So overall, I think that developing dorsiflexion during swing phase is probably important for a specialist sprinter, but I am less clear about its value for a distance runner who needs to increase stride length.

  6. Ewen Says:

    Thanks Canute — it’s good that you seem to have the training stresses in balance.

    Regarding b/Km… one thing I’ve noticed, is that after a particularly hard session (or a race), I have a lower b/Km the following day than I’d usually have for that session (considering weather conditions). Also a lower than usual standing HR prior to running. Any thoughts on the reason for that?

  7. Rick Says:

    Canute checkout page 17 [ fig 1.11] effects of early and late takeoff.

    I strongly feel that dorsiflexing the ankles on landing reduces braking for the simple reason you are pulling your leg bone forwards helping the leg rotate forwards over the ankle joint. lack of flexability in the ankes will be like putting the brakes on, Arthur lydiard talks about the importance of ankle flexon in this [ exercise 3] hill drill session and also in his books

  8. Rick Says:

    DEFLEX ???

  9. canute1 Says:

    I agree. Thanks for clarifying what you had intended. In my initial response I was discounting the importance of any work done by active dorsiflexion in early stance, but accept that it is important to allow passive dorsiflexion. My belief in the value of passive dorsiflexion is related to my belief that the heel should be allowed to drop to the ground by midstance. I therefore agree that flexibility of the ankle is important as it would be expected to diminish braking, as you say, as well as allowing the longitudinal arch to take a bit more of the load. In addition, the passive dorsiflexion will increase the tension in the calf muscles which will help facilitate the subsequent plantar flexion in late stance.

    Today I did a bit more experimenting with active dorsiflexion during the swing phase, while sprinting. I achieved a longer stride – my maximum stride length was 1.95m, which I was pleased with, though I suspect I had a stride much greater than 2m as a youngster. So I accept that active dorsiflexion of the ankle during swing is helpful when sprinting though I remain uncertain how important this is for the distance runner.

    That Lydiard Foundation hill training video is great. Thanks.

  10. canute1 Says:

    I usually find b/Km for a particular run is greater on the day after a heavy training session, suggesting increased cortisol and increased adrenaline (i.e. stress). I would anticipate that if the stress is really excessive there might be parasympathetic excess leading to a lower HR. I observed that phenomenon last summer when I overdid things on my return to training after illness, but I think it is very unlikely that is what is happening to you after a race or heavy session. So I am afraid I cannot offer an adequate explanation. If I had to guess regarding possible mechanisms, I would look into the question of how quickly blood volume increases after a training stimulus. An increase in blood volume would lead to enhanced stretching of the heart muscle during diastole, and this would increase efficiency of cardiac contraction. However I have never observed this hypothetical effect in myself

  11. Rick Says:

    Glad to here your stride has increased.
    I was thinking If you find it hard to land on your ball of the foot without plantarflexon maybe the shoes you wear are designed for heel striking and have too high a heel.
    I cut down the heels on most of my shoes and find I can run with a much better running action.

  12. canute1 Says:

    Rick, Today when sprinting I was wearing racing flats, and that certainly helps.
    However for long runs I wear the light weight Adidas Supernovas, which have a modest heel – I do not think the model I have are still made, but it is similar to the Supernova light 6. Ideally I would like something with even less heel thickness, but I haven’t found anything that is wide enough in the toe box to accommodate my distorted forefoot while also having minimal heel.

    When running long distances a somewhat longer time on stance is desirable – even the elites spend longer on stance at slower speed. Due to the requirement of conservation of angular momentum, longer time on stance inevitably results in landing a bit further in front of the COM – and this precludes substantial active dorsiflexion before footfall if one aims to land on the forefoot or midfoot.

  13. Ewen Says:

    Canute, sometimes I find the b/Km is higher following a long slow or long mid-paced run. I find it’s lower following a high intensity run – for example, high tempo pace, a short race, or intervals. I’m wondering if it’s a minor training effect – that the heart/circulation has adapted from the stress of the session and provided a ‘bounce’ to a lower HR?

    Thanks Rick for the Lydiard and D-flex videos. Interesting.

  14. canute1 Says:

    I agree that the reduction in b/Km following a single intense training session or race suggests that a single session is enough to produce an appreciable training effect. As mentioned in my previous response, I think the most rapid training response is increase in blood volume. However other short term effects might occur after intense sessions. For example, testosterone levels rise after intense exercise but tend to fall after prolonged exercise. Protein synthesis within 24 hours can be appreciable. Also, intense activity might produce rapid neural adaptations. So it is clearly plausible to get observable beneficial effects on b/KM within 24 hours following intense activity, though one probably cannot continue to pile up the benefits because once the total volume becomes too large, the damaging effects of fatigue will set in. In my own experience, I am more used to observing increase in b/km following hard sessions, but maybe I need to look more closely at what happens following short, sharp sessions.

  15. Simon Wegerif Says:

    Hi Canute, and a happy new year to you and your readers!

    For your future consideration of autonomic function vs short term accumulated fatigue and medium term fitness improvement, I would like to make you aware of a new publication in Eur J Appl Physiology Dec 2009 by Martin Buchheit et al ‘Monitoring endurance running performance using cardiac parasympathetic performance’. It would be especially interesting to see how changes in b/km also correspond to these parasympathetic index changes.

    kind regards

  16. canute1 Says:

    Simon, Thanks for the details of the paper by Buchheit and colleagues. It confirms that both changes in resting and recovery HR variables are related to improved fitness, though the relationships have only moderate predictive value for an individual. It seems to me that the really interesting variables are the values recorded while actually running. However, variation in HR due to fluctuation in work rate makes the interpretation of HRV while running, more complex. So paradoxically, while HR during exercise is widely used as a measure of effort during sessions , HRV during exercise has not yet proven to be a useful index, as far as I am aware. However, my own observations do suggest that parasympathetic indices when working in upper aerobic zone might be potentially a useful indicator of fatigue. Do you know of any good studies of parasympathetic indices during vigorous exercise?

    • Simon Wegerif Says:

      Hi Canute

      Vagal modulation of heart rate during exercise: effects of age and physical fitness by Mikko Tulppo in AJP-Heart is one of the most cited studies. Most researchers have found a rapid exponential withdrawal of vagal modulation with increasing workload up to the first ventilatory threshold (for reasons that are not widely understood) then an apparent absence of parasympathetic HRV up to VT2, followed by a small increase, likely due to non-neural mechanical stretch of the sinus node. The area under the graph of parasympathetic HRV vs workload has been proposed as an index of work capacity by Dr Mike Lewis of Swansea University. I have not seen any references to the action of Porges ‘vagal brake’ to limit HR during exercise. Hope this helps!

  17. Rick Says:

    The Effect of Running Shoes on Lower Extremity Joint Torques

  18. canute1 Says:

    Rick, Thanks. I have been intrigued by that journal article since I first saw it mentioned in the Guardian a few weeks ago. The fact that shoes with built-up heels and motion control posts cause greater torque is what I would have expected, but the magnitude of the increase is far greater than I would have expected.
    The simple conclusion is that we should wear shoes within minimal heels, but there are probably other interesting conclusions to draw. The control of pronation is a less clearcut issue. However there is little doubt that a moderate amount of pronation is good and should not be prevented. I have been thinking about doing another post on shoes and foot dynamics.

  19. Rick Says:

    Hi Canute,
    In the report it says when wearing the shoes the runners took longer strides than when bare foot, does than mean the shoes encouraged heel striking?
    I still wonder why the main running shoe companies do not make a range of shoes for ball of the foot and midfoot strikers!
    Out of interest my modified nike explosions use to allow me to run for about 10 miles befor my feet started to hurt, now with the cut down heels i can manage about 16 miles before my feet start to feel the pounding from the roads!
    my lunar trainers are may be the best shoe i have come across for my long Distance runs.
    i look forward to your next post on shoes.

  20. canute1 Says:

    I do not think the longer strides when wearing shoes are likely to be due to heel striking. The pace was the same barefoot and shod, so the cadence must have been higher when running barefoot. When cadence is higher the duration of each stride is shorter and the proportion of time on stance is likely to be a little longer leading to lower vertical ground reaction force, as was observed. Thus I think it is likely that the runners automatically increased their cadence to minimize the pressure on the soles of their feet when barefoot.

    The investigators showed that the longer stride only accounted for a minor proportion of the larger torque at the joints. While the difference in stride length (and cadence) is not the major factor in producing the difference in torque at joints, it is another factor that needs to be taken into account when evaluating barefoot v shod running.

    Up to a certain point (probably around 200 steps per min) increasing cadence is likely to be helpful, but beyond that point, increasing cadence at the expense of stride length is probably inefficient. So in this respect, barefoot running might be less efficient some circumstances – for example when sprinting. However, at moderate paces, barefoot running is likely to be slightly more efficient.

  21. canute1 Says:

    Thanks for the recommendation of Tulppo’s study. I will get hold of it and read it carefully. I note that it is usual to see diminished parasympathetic influence above VT1. In contrast, my HR quite often shows high frequency fluctuations of moderate amplitude, which I assume reflect parasymapethic influence, when I am maintaining a constant pace at HR midway between estimated VT1 and VT2. Here is a Poincare plot representing 3 min of data recorded during an easy tempo run with HR midway between VT1 and VT2. SD1 = 7.9 ms and SD2 =7.0 ms.

    [Sorry, the insertion did not work – the Poincare plot showed a cluster of points with almost as much spread across the 45 degree line as along the 45 degree line]

    Sometimes, when I am finding it a major effort to maintain HR above VT2 even for a period of a few minutes, I exhibit prominent high frequency fluctuation of HR– in my case these high frequency fluctuations at HR above VT2 appear to be a sign of impending fatigue and I take it as a sign that I should have a few easy days. So far, I think the evidence tend to suggest I have a fairly active parasympathetic system which I hope represents a mechanism protecting me against undue stress on the heart. However I am a bit disconcerted by the evidence suggesting that high frequency HRV during exercise might not reflect healthy parasympathetic activity.

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