Re-appraisal: the benefits and damage produced by cortisol

This year has been frustrating in an undramatic but challenging way.  Undramatic because I have remained free of overt injury apart from some persistent though relatively mild problems with my joints and ligaments, but challenging because it has not been easy to identify why my fitness improved so slowly and then degenerated so rapidly.  I achieved a greater volume of training –  approximately 2000 miles (including the mileage equivalent of my elliptical cross-training sessions estimated on the basis of 100Kcal = 1 mile)  than in any year in the past four decades.  Taking account of my slower training paces, it is probable that I have actually spent more time training this year than during any year in my entire life.  Yet through the summer I was frustrated by the tardy rate of improvement in fitness.

There were few occasions when I experienced the exhilaration of running fluently and powerfully.  I felt tired much of the time and experienced persistent aching of the connective tissues in my legs.  My short term goal was a half marathon time faster than 101:50.  Despite the fact that I was unable maintain a pace of 5 min /Km (corresponding to 105:30 for the HM) for even a few Km as the date of the event approached, I nurtured the hope that a three week taper with some drills and faster running to sharpen my pace, would allow me to defy any rational prediction based the evidence of my limited fitness.  However, in the event, rational prediction was indeed confirmed and despite a spirited finish, I recorded a time of 107:45.

In the aftermath I took some consolation from the fact that I had coped with a large volume of training without injury, though I was aware that I would need a few easy months to allow my body to recover.  I cut my training volume to an average of slightly less than 30 (equivalent) miles per week, including an increased proportion of elliptical cross-training.   After a month or so, I added a modest plyometric program as described in my previous post.   The encouraging outcome was a modest improvement in hopping and jumping, indicating some gain in musculo-tendonous resilience and eccentric strength, but the dominating feature of the final few months of the year has been a devastating loss of fitness.     Although I had cut my training volume substantially, the cut was less ruthless than the cut forced upon me by an episode of arthritis a year ago, yet the loss of fitness has been far greater.  I am now at my lowest ebb since summer 2011 when a hectic and exhausting six months at work had left me with neither the time nor energy for solid training.  In 2011, my lack of fitness illustrated the fact that for the elderly, fitness is hard won and easily lost.  But in 2013, I am facing the disconcerting question:  has fitness  become even more difficult to gain and easier to lose as I have moved from my mid to late 60’s, or did I do something wrong this year?

I had used submaximal tests throughout the summer to ensure that I was just one step short of over-training, as indicated by autonomic measures of stress, such as heart rate at submaximal effort and resting heart rate variability.  However, perhaps I should have taken more notice of the chronic tiredness and aching legs.    I suspect that my mediocre half marathon performance demonstrated that I was not merely over-reaching but that a least a mild degree of over-training had interfered with my ability to benefit from training.   This lurking suspicion has been strongly re-enforced by the devastating loss of fitness since September.  It is clear that I had not built a sound base.

In the past few months, I have continually questioned whether or not I simply needed a bit more rest, but on the occasions when I have cut back the training volume even more drastically for a few weeks, the deterioration in fitness has accelerated.   So the evidence suggests that I was not merely in a state of functional over-reaching from which the body bounces back with renewed vigour after a brief respite.  I had almost certainly over-trained. I was in need of a more profound rest.  Yesterday, I ran 11 Km, the longest distance I have run in recent times.  My pace was very slow – around 6:30 min/Km – but for the first time since September, my legs did not ache.  I hope this indicates that I have now passed the nadir, and can again begin re-building, but very cautiously.

Do miles make champions?

Arthur Lydiard’s simple dictum, ‘miles make champions’ is undoubtedly true.  Indeed the rapid crumbling of my fragile fitness base as I have cut back the training volume since September confirms the crucial role of training volume.  But just as every wise proverb can be countered by one that draws the opposite conclusion, miles can also undo would-be champions.   In the summer, the most striking contrast with my training of recent years was the much greater proportion of long runs, mainly at a quite slow pace.  I think it is likely that I did too many long runs this year.   As I discussed in a post in October, Dudley’s studies of rats who ran at various intensities for various durations, showed that the increase in the mitochondrial enzymes that are essential for aerobic metabolism reaches a plateau after a sufficiently long duration of running. The plateau was achieved late, and was highest, in the rats that ran at the modest pace of 30 metres/min which they could maintain comfortably for over 90 minutes.  A somewhat faster pace of  40 m/min, which was near to the peak pace that they could maintain for 90 minutes, produced a slightly lesser gain in aerobic enzymes.   Paces below 30 m/min achieved an even lower plateau. On the other hand, at paces faster 40 m/ min the gains in fitness were more rapid but the duration for which the animals could sustain the pace was less and consequently the total gain in fitness was less than that achieved at 30 m/min.

Rats differ from humans in many respects, and the actual paces of animals with legs of only a few centimetres in length are of little relevance to humans, but the muscle physiology of rats is essentially similar to ours. It is likely that similar principles govern the effects of training.  There appear to be two major conclusions.  First, the greatest gain in aerobic capacity is achieved by a ’good aerobic pace’ that can be maintained comfortably for 90 minutes.  Second, there is a limit to the benefit in aerobic capacity obtainable by increasing the length of training sessions.   There may be other benefits of long runs, such as strengthening of connective tissues. But the occurrence of the plateau in development of aerobic enzymes suggests that at that beyond around 90 minutes something inhibits the further development of aerobic enzymes.  Perhaps the most plausible limiting factor is the accumulation of cortisol.

Skoluda and colleagues have demonstrated that endurance athletes exhibit a sustained elevation of cortisol, and furthermore, the magnitude of the increase correlates with greater training volume, measured in either hours per week or distance per week.   Cortisol is a catabolic hormone that promotes the breakdown of body tissues, including muscle, while inhibiting the synthesis of new protein.    To evaluate the plausibility of the proposal that cortisol limited the synthesis of aerobic enzymes in Dudley’s rats and also played a part in my mediocre half marathon and the subsequent crumbling of my aerobic base, it is necessary to re-examine some of the details of role of hormones in the regulation of energy metabolism discussed in the first of my posts comparing the Paleo diet with a high carbohydrate diet.

Cortisol

At the commencement of exercise, there is an acute elevation of cortisol, together with adrenaline, that mobilizes the body’s resources to meet the demand for increased energy.   The generation of  glucose from glycogen is stimulated, thereby releasing the fuel that can be utilized most rapidly for muscle contraction.  Cortisol also stimulates the metabolism of fats and of amino acids.   Conversely, protein synthesis from amino acids slows down and body systems that serve longer term survival needs are put on hold.    The immune system and the gut suffer first, though as long as the muscle continues to generate the amino acid glutamine, which helps sustain both immune cells and the lining of the gut, these body systems continue to function reasonably well.   However, as the duration of exercise extends into the period when glycogen stores show signs of depletion, cortisol level rises further.   Now the body’s priority is ensuring adequate supply of glucose for the brain.  The increased level of cortisol inhibits the glut 4 carrier proteins that transport glucose into muscles.    The muscles are increasingly reliant on the relatively slow production of energy via fat metabolism.  Meanwhile, synthesis of glutamine drains the pool of intermediate metabolites that participate in the Krebs cycle, the closed-loop of metabolic transformations that plays a central role in energy metabolism and also in the synthesis of amino acids.  Although fat metabolism can keep the Kreb’s cycle going, it cannot top-up the pool of intermediate metabolites.  This topping-up requires input from pyruvate which is generated by the metabolism of glucose.  In the absence of concurrent glucose metabolism, glutamine levels begin to fall, impairing the function of both the immune system and the gut.

Thus, the immediate effect of the elevation of cortisol is the provision of fuel for exercise, but as glycogen supplies diminish the priority is provisioning the brain, and the rest of the body suffers.  How long does it take for this to occur?   Cook and colleagues recorded salivary cortisol levels in recreational runners both during and after a marathon. The highest level was almost 6 times higher than typical morning levels, recorded 30 minutes after completion of the event, but the level had risen steadily throughout and was already very high by 25 miles.  Similar levels were recorded following a non-competitive marathon.  Thus, an appreciable elevation of cortisol is likely even during long training runs, consistent with Skoluda’s finding that endurance athletes have chronic  elevation of cortisol that rises in proportion to training volume.

What are the potential adverse medium and long term consequences?  The acute anti-inflammatory effect of cortisol is likely to hinder the repair and strengthening of muscles and other body tissues.  In particular, the synthesis of aerobic enzymes is inhibited.  Suppression of immune function creates the risk of infections.  Sustained elevation of cortisol will sustain a balance that favours breakdown rather than building up of tissues, and thereby promote further loss of fitness.  Furthermore, prolonged exposure to high levels of cortisol decreases the sensitively of the receptor molecules that mediate the effects of cortisol on body tissues, and might ultimately promote chronic  inflammation, harming joints and connective tissues while promoting the deposition of atheroma in blood vessels.

In my own situation, I suspect that a continuing bias towards catabolism rather than anabolism has hastened my loss of fitness, while the continued aches in my legs probably reflected chronic inflammation in the ligaments.  On the other hand, I have been pleased to note that I have not suffered any exacerbation of asthma this year.  I hope that any tendency towards increased formation of atheroma in my blood vessels has been minor.

Next year, I plan to train for a marathon.  But if I am to achieve a more robust fitness base and even more importantly,  to enhance rather than harm my long term health, I need to adopt a different training strategy.   I should start with a more careful scrutiny of the past year.

Closer scrutiny of the training log

While the most immediately apparent feature of my training during summer of 2013 was the relatively high proportion of long runs, a more careful inspection of my training log reveals a potentially more significant issue.   After the resolution of arthritis in the early months of the year I had gradually increased my training volume up to 30 (equivalent) miles per week, and was coping well.  Then, in March I increased the volume quite rapidly, by almost 15%  each week for 4 weeks, up to 50 (equivalent) miles per week by early April.  The submaximal test revealed that my fitness continued to improve fairly steadily until mid-April, but then suffered a slight decline in May, so I reduced the weekly volume back to 45 (equivalent) miles per week.  Once again fitness began to improve, albeit slowly and I was feeling tired much of the time.  I continued at that level of training until mid-August when I once again increased to 50 (equivalent) miles per week, but that produced only a marginal further increase in fitness by late September.   At the time, it appeared that I had pushed myself to the limit but had not quite over-stepped the mark.  However, in retrospect, I think I had overdone it.  The damage was probably done in March and early April when I had increased training volume by 15% per week. At that time, all had appeared well, as my fitness continued to improve. Indeed from mid-March to mid-April I saw the greatest gain in fitness in any month of the year.  It appeared I had got away with a relatively minor infringement of the 10% rule.  But the increases in weekly volume reflected another feature, an increase in the number of long runs.  By late April, I was occasionally slipping in two moderately long runs within a single week.  I suspect I was accumulating a surfeit of cortisol that led to the transient decline of fitness in May, the mediocre half marathon in September and  the subsequent devastating loss of fitness.

Plans for the future

I have about nine months until my target marathon next autumn.   This gives me five months to build a solid base, leaving four months for specific marathon preparation. The cardinal goal of the final four months will be developing the capacity to sustain marathon pace for 26.2 miles.  The goals of the preceding five months of base-building  are more varied.

First, I need to ensure that my connective tissues are well conditioned and free of any trace of lingering inflammation.   I will need to adjust my training over the next few months according to how well the recent recovery is maintained.  I will continue with moderately demanding weight sessions and some mild plyometrics.  It is likely that I will do a greater proportion of my aerobic training on the elliptical cross trainer next year, and I will build-up the long runs very gradually, aiming to increase from the current 11 Km to 25 Km by late spring.

Secondly I aim to develop the ability to utilise fat in preference to carbohydrate at low and mid-aerobic paces, thereby minimising the risk of excessive elevation cortisol during long training runs.  The main element of the strategy to achieve this goal will be a gradual increase in training volume, especially in the low and mid-aerobic zones.    I will also maintain my current nutrition, consuming a diet that matches the Mediterranean diet as described in my post two weeks ago.

My third goal will be the development of aerobic capacity, including the ability to utilise lactate.  The gradual increase of training volume in the low and mid-aerobic zones required to promote utilization of fat will also contribute to this goal.  In addition, I will do regular sessions similar to Hadd’s 25×200/200 sessions, in which brief epochs that are effortful enough to generate a modest amount of lactate, alternate with recovery periods long enough to allow the metabolism of the lactate.  Because there is minimal accumulation of acidity the session is only moderately stressful.

Fourthly, I will attempt to build up the strength to maintain a reasonable marathon pace without the need to increase cadence to an inefficient level.  At present, my cadence exceeds 200 steps per minute even at 5 min/Km.  My strategy for developing the strength required to lengthen my stride includes a mixture of short hills, long hills and sprinting in addition to weights and plyometrics.  A key feature of all of these sessions will be generous recovery after each effortful epoch, to maximise the stimulation of anabolic hormones and minimise cortisol production.

Above all these specific goals, I will aim to start the marathon specific training in a robust and relaxed state.

28 Responses to “Re-appraisal: the benefits and damage produced by cortisol”

  1. Jerry Griffin Says:

    Good for you — your persistence and intelligence are both admirable.

    Brief comment about my own experience. At 74 years old, I have reduced my running to a minimum; I felt that the pounding of long distance running was no longer beneficial for me. I’ve switched to CrossFit — three times a week — plus rowing on the Concept2 erg to keep up with the need for long slow distance work’s aerobic effects. I track the sorts of metrics that you do, and find that my Polar fitness metrics are better now than they were when I was doing triathlons in the mid-2000’s. So, based solely on my own experience, I conclude that intense, highly-varied interval work can be valuable — though I doubt that it can ever replace the pleasure of running that has obviously been so satisfying to you.

    • canute1 Says:

      Jerry,
      Thank you for your comment. It is re-assuring to hear that a program of intense and varied interval work, together with sessions on the erg have allowed you to maintain a level of fitness superior to when you were training for triathlons. As for the joys of running, it is a shame when age forces the decision to relinquish any enjoyable activity. In my own case I would certainly like to run at least one more marathon while I can, but if needs be I will settle for running through the local woods and along the river bank. Nonetheless I have been intrigued to find that rather repetitive elliptical sessions have their own interest, while lifting weights is quite satisfying. I hope you continue to enjoy your varied program.

  2. Mike Says:

    I see you are aiming to lengthen your stride – is this not a consequence of running faster, rather than the cause?

  3. canute1 Says:

    Mike,
    The arrow of causality points both ways. When you decide to run faster, both your cadence and your stride length increase automatically, though the proportional increase in stride length is much greater than the proportional increase in cadence. Typically, if speed doubles, stride length increases by about 75% while cadence increases by about 15%. The brain apparently adjusts these relative increases to minimise total energy expenditure.

    Of the three main energy costs of running (getting airborne; overcoming braking and repositioning the legs) the one that increases most rapidly with increasing speed above paces of 4 m/sec is the cost of repositioning the legs. This cost increases in proportion to the product of speed and cadence, so at high speed it advantageous to increase stride length proportionally more than cadence.

    However there is an additional factor: it requires good strength and coordination to deliver the effective push required to generate a long stride. If you cannot deliver an effective push, you are forced to produce an inefficient increase in cadence.

    As I have got older, I have lost the ability to deliver an effective well-coordinated push (like most elderly runners). Even at sprinting pace my maximum step length is barely 1 metre. To achieve a pace of 5 min/Km I am forced to increase cadence to more than 200 steps/min. This is inefficient. If I could increase the effectiveness of the push to drive my body up and forwards off stance, I could run more efficiently.

  4. Jerry Griffin Says:

    I’m aware of your investigations into the Pose method of running. I am a Poseur. I’ve never tried consciously to increase my stride length, nor to increase my cadence beyond the 185 – 190 rate. Somehow, I just think “faster”, lean into it, and it happens. I suppose I should measure what actually happens when I lean into it …

    • canute1 Says:

      Jerry,
      If you can increase speed above 3.5 m/Sec without increasing cadence above 200 steps per minute, you are capable of a stronger push than me. I wonder whether you Cross-Fit training has preserved your leg strength and coordination.

      Leaning itself cannot generate push though of course it does encourage you to drive off stance and get the swinging leg forward in time to avoid a face-plant. Furthermore when your leg is angled backwards from your trunk, you are in a mechanically sound position to push. Some coaches encourage conscious hip extension in late stance, but I find that very tricky to achieve, without delaying lift-off.

  5. ajh Says:

    Thanks for your comment on my blog. I’m impressed by the specificity of your goals, hope they are acheived. Do you have a target time in mind for the marathon? I think this year I’ll be aiming at a 5 or 10Km maximum.

    • canute1 Says:

      Andrew,
      I think that aiming for 5 K or 10 K is a sensible start, and maybe these are the ‘healthiest’ distances for recreational athletes to focus on. I would certainly not run a marathon primarily of the sake of my health, though I hope that careful avoidance of over-training will allow me to train for a marathon in a healthy way. I will set a time target at the end of May after I see how well I recover from my present state.

  6. Mike Says:

    Your comments on stride length are interesting. Are you planning on reaching out further in front, pushing off more behind, or both?
    It is my understanding that both tactics just increase energy wastage – fast runners only look like they are reaching/pushing, but it is largely an illusion that we are still fooled by.

    • canute1 Says:

      Mike,
      The push is not an illusion. Running requires a forward push to overcome the inevitable braking that occurs when the foot is on the ground, and an upward push to get airborne. The only way these pushes can be delivered is by pushing back and down against the ground. Contrary to the implication of Pose, gravity cannot deliver a net horizontal impulse and it certainly cannot lift you upwards. Experimental evidence such as that provided by Peter Weyand in Journal of Applied Physiology, 108:950-961, 2010, confirms that faster runners generate a stronger push. Note than only a minor fraction, typically around 45% of the push, can be provided by elastic recoil.

      The tricky issue is how to deliver this push. Skilful runners such as Usain Bolt do consciously push. His statement ‘Get tall, knees up, dorsiflex, get your toes up, plant, push again’ reveals that he consciously pushes when his foot is planted. (Unfortunately the original U tube clip in which he makes this statement is now inaccessible though this quote appears on several blogs including my own:

      http://canute1.wordpress.com/2012/03/11/does-usain-bolt-run-pose-style/

      However for most recreational runners, consciously pushing is counterproductive as it tends to result in a longer time on stance. Consciously reaching out with the swinging leg also tends to increase time on stance because the foot lands too far in front of the body creating a greater braking force and therefore demanding an unnecessarily large push back against the ground to overcome it. I think that for most recreational runners it is better to focus on getting off stance quickly. This necessarily demands a greater vertical push while diminishing the need for horizontal push by virtue of less braking. Perhaps ironically, despite the faulty theory underlying Pose, I think Pose is a quite a good style for recreational runners because it discourages conscious push, though the drills actually help develop a stronger push.

      However if you lack the strength and coordination to get off stance quickly (as I do), you need to do some preparatory drills and exercises. In the elderly, weight lifting helps recovery of strength and plyometrics improve coordination and resilience. I am employing both of these strategies but so far with limited success. I wonder whether perhaps at present my brain will not allow me to exert a strong push in order to protect my fragile joints.

      • Mike Says:

        I think we largely agree – your 3rd paragraph sums up my understanding of how we run. Once up to speed we push up more than back, and the leg only ends up behind us because it takes time to slow it down, not because it is pushing to any extent. Leg strength is what it is all about, and strength is of course a skill, and it is nice if as much as possible of that strength is plyometric.

  7. Jerry Griffin Says:

    Working in feet and miles rather than meters, I think you are suggesting that speeding up beyond a 7:40 m/m pace requires either a cadence probably exceeding 200 steps/min, or a stronger push than you currently can muster. I don’t know, but since I have often run with a metronome as well as the Polar gps gear, I should be able to figure it out.

    I will say that AT THE MOMENT, I am surprisingly strong, sometimes surpassing in strength and speed the 20-to-40 year-olds in my CrossFit sessions. I don’t know why; I have no expectation that it will last; just that it is currently so. I seem to be an anomaly, often (for instance) ranking # 1 or # 2 in the world indoor rowing rankings in my age group, and testing as physiologically (?) more like a 35-year old than 74. OTOH, I struggle with the same concerns that you do, including observing the effects of aging, rapid deconditioning, and repeated resetting of goals to take into consideration my failures to meet my training goals and my own expectations.

    BTW — it is obvious to me from your previous posts that for many years you were a FAR superior runner than I; perhaps you are now, as well. I think my fastest 5K pace ever is around 7:05 m/m (i.e., about 22 minutes, accomplished during a sprint triathlon several years ago), and I have never raced a 10K or a marathon. Go figure!

    • canute1 Says:

      Jerry
      I look forward to hearing what you discover about your stride length and cadence.

      I am also impressed by the fact that in strength and speed you can outdo the youngsters in the CrossFit sessions. Individuals differ in their proportions of type 1 (slow twitch) and type 2 (fast twitch) muscle fibres. Furthermore the type 2’s tend to degenerate faster with age. Maybe you were naturally endowed with abundant type 2 fibres and your continued participation in CrossFit has helped to maintain them. On the other hand I think I was naturally endowed with a preponderance of type 1 fibres. Type 1 fibres do most of the work during long slow runs and probably made me a better marathon runner than track athlete. However as I have grown older, and many of the sparse type 2 fibres I was born with have withered away, I have lost the power in my stride.

      • Jerry Griffin Says:

        I’ve never been sure about the fibres. I’m definitely not fast, explosive, or powerful, at least not now. I’ve always been much more an endurance type, like you, inclined to long rows, long cycles, long runs (sorta). Still, I may have had a bunch of type 2s that I never activated, since I never competed in anything until into my mid-60s, so I never found out what I was equipped to do. I’m also inclined to the theories about ATI — Acquired Training Intolerance. I have a friend, formerly a 15-minute 5K runner, who in his early 60’s suddenly can barely run 400m. There is some evidence that people who’ve spent their lives running sometimes suffer a disorganization of their cell structure, leading to an inability to sustain certain types of activity like running and rowing. Ever heard of it? He is about to have a biopsy to see whether he’s got cellular disorganization.

    • canute1 Says:

      Jerry,
      There is little doubt that fitness can be lost in dramatic and apparently irreversible steps. Sometimes these losses are clearly associated with identified over-training and in such cases there is often evidence of muscle damage, though why this should be irreversible is difficult to determine.

      At a cellular level, one of the markers of age-related degeneration is loss of the length of telomeres: the caps on the ends of chromosomes that tend to get shorter as the body ages. Some studies report that former athletes with acquired training intolerance have shorter telomeres in the satellite cells. Satellite cells are a type of stem cell and are essential for repair of muscle damage. These cells fuse with damaged muscle fibres and then replicate. Shortening of telomeres might indicate a reduced ability of these cells to replicate. However the question of the degree to which telomere shortening might be reversed by diet and/or exercise remains controversial.

      One of the reasons I pay so much attention to the issue of over-training is my wish to understand more about the nature of apparently irreversible losses of fitness, and to determine whether or not they are truly irreversible. But at this stage these complex issues are poorly understood.

  8. Robert Osfield Says:

    Seasons Greetings Canute :-)

    I feel frustrated for you with your struggle to build and then maintain fitness. I wonder if there are other things going on than chronic elevation of cortisol. Could it be that your arthritis might be lingering in a low level way impacting your ability to train?

    With your coming year I think it might be worth looking at introducing doubles or even trebles of daily training to reduce the length of each individual session so that you can modestly refuel between sessions and avoid risk of elevated cortisol. If I had the time to do it I would do doubles myself.

    • canute1 Says:

      Robert,
      Happy New Year. I hope that it is a good year for you and your family, and in particular, hope that training for and racing the WHWR goes well.
      I agree that doubles is a potentially a good strategy to minimise cortisol accumulation. Indeed I am about to begin my second session for today – a short low intensity elliptical session.
      Some studies show that the gains in aerobic enzymes in animals are at least as great after doubles as after a single session of equivalent total length

  9. Ewen Says:

    All the best for 2014 Canute. Your strategy for the marathon preparation makes sense to me. I hope the problems that kept me from taking up residense in a mansion in Forrest are held at bay throughout the year.

    My fitness has declined recently due to a troublesome recovery from a hamstring injury. I reached a level lower than I’ve been since 2006 – 845 heart-beats per km for an 8k run (best last year around 700 for the same distance when training).

    My comeback strategy revolves around repeating the same daily distance and modestly longer ‘long’ runs. At the moment, 8k per day, 5k if I need an easier day, 11 or 12k for a ‘long’ run. I’m judging how well I’m coping with the training by how well I back up from day to day. When I back up well from day to day for a number of weeks, I plan to increase the daily distance to 9k, then 10k. The long run to perhaps 15k. Regular modest tempo runs (at the Parkrun) and occasional ‘all-out’ races are part of the plan. Hoping my weekly volume of running can be comfortable at around 65-70 km with additional rowing on the Concept2 erg for cross-training.

    • canute1 Says:

      Ewen,
      Best wishes for 2014. Sorry about the mansion in Forrest But the other frustrations you have experienced in the past year have perhaps been even more important. For both of us, the early months of the new year will be about careful re-building of fitness. I think that for both of us the cross-training is likely to be important.

      I wonder about the relative merits of the erg and the elliptical. There is little doubt that the erg provides a very good ‘whole body’ work-out. The elliptical places the greatest demand on the leg muscles, while making only gentle demands of the joints. I think that is what I need at present. However, I anticipate that my aging elliptical will grind to a halt before I do, and then I will face the question of whether to replace it with another elliptical or with an erg.

      • Ewen Says:

        Interesting conundrum. Buy both! I like the erg for the following reasons:
        1. Very similar to actual on-water rowing and they have a great website to compare your own performances with others’ around the world.
        2. Uses the quads more than the hammys. I was able to row when I had the hammy and lower calf niggles. Uses the core, back and arms.
        3. HRs are generally lower than running (sitting down). MAF effort HR for me running (130) is about 120 on the erg, although I can get up to mid-140s sprinting at the end of a session.
        4. 5k or so on the erg (22-3 minutes) is enough to get a good x-training workout. The computer has in-built sessions.
        5. If I want an easy row I can watch TV while doing it as the head is only moving back and forwards, not up and down.
        6. Running fitness benefits erg performance and vice-versa.

      • canute1 Says:

        Ewen
        I am pleased to hear that you find that running fitness benefits erg performance and vice-versa. My own observations show that this is to a large extent true in the case of the elliptical cross trainer. A few years ago, I tested my pace at 2nd ventilatory threshold before and after a 6 week aerobic program on the elliptical during which I did virtually no running. My pace at 2nd ventilatory threshold while running increased by 5% (and beats/Km decreased by a similar proportion).

        However, similar to your observation that ‘MAFeffort’ HR on the erg is lower than when running, I also observe that the 2nd ventilatory threshold occurs at a lower HR on the elliptical compared with running. I think this is because I am using a higher proportion of type 2 fibres and hence generating more acidity at a given HR, even in the aerobic zone. Acidity provides a strong stimulus to respiration. If this hypothesis is true, then it should be possible to develop capacity to metabolise lactate with a lower level of stress on the heart (though at the cost of greater respiratory discomfort) on the elliptical. I wonder if this is also the case on the erg.

  10. Why do marathon runner slow down – the role of muscle damage | Canute's Efficient Running Site Says:

    […] « Re-appraisal: the benefits and damage produced by cortisol […]

  11. Ewen Says:

    That could be so Canute. I know my arms and to a less extent, legs, go lactic at a lower HR on the erg but I thought that might be due to relatively weak arms (compared to well trained running legs). My mileage on the erg is quite low – about 6k a week over 3 sessions would be an average.

    • canute1 Says:

      Ewen
      I find that I breathe more deeply on the elliptical than when running even after a period when I have spent more time on the elliptical, so I think that recruitment of type 2 fibres is the main issue rather than either strength or familiarity with the action. As you say, on the erg you work your arms quite hard. I suspect that type 1 fibres are much less developed in the arms than the legs even in people with relatively strong arms.

  12. EternalFury Says:

    Hello and Happy New Year!

    I did not run my planned marathon last December. I developed a niggle in my left foot and decided to skip the event.
    The whole thing came about as I got a new job and started to prepare for a relocation more than 1,000 miles away, leaving a job I had held for more than 14 years.
    The cumulative stress of training and turning my life upside down probably led to the niggle.

    I agree with the content of this post.

    All of us are in dear need of 2 new sensors:

    – A lactate sensor
    – A cortisol sensor

    And when I say “sensor”, I mean devices that will monitor “lactate” and “cortisol” in the same way current HR monitors log HR.

    Until then, we are going to keep running along the red line, sometimes crossing it without realizing it.

    • canute1 Says:

      EF
      Thanks for your comment. I am sorry to hear that your developed a niggle in your foot that stopped you from running the marathon in December. I hope that 2014 is good year for your running, that you remain injury free and the new job and new location work out well for you.

      Yes we need better sensors that monitor the physiological changes that indicate risk of harm. Maybe measures that can be applied after run, or perhaps once per week would prove to be of greatest utility.

      I continue to use my submaximal test which I think does give a reasonable estimate of autonomic indices of stress. However my conclusion at the end of 2013 was that despite successfully staying just below the level of excess autonomic stress, I failed to monitor the cumulative damage to my aging legs. I am at present experimenting with a test of maximal voluntary contraction of glutes, hams and quads which is simple and less stressful than a maximal countermove jump. I think that MVC of the major muscles is fairly sensitive to cumulative damage, but I am not confident that I can obtain reliable measures using the primitive equipment available to me.

      • EternalFury Says:

        I am with you. I have been very careful in 2013, monitoring my HRV and my PMC very carefully. Yet, I crossed the red line, apparently. Before we got started with the move and all the nasty packing it entailed, we had a trip to Disneyland scheduled…where I walked 8-10 hours a day every day. I bet that’s where I lost it…I still wanted to run a little and I went for a 7 mi run after the 3rd day! Yes, I have no common sense, apparently. Getting injured 10 days before a marathon, during a taper, no less, is the most regrettable thing ever.
        But the past is the past.
        I am now in Colorado, literally a mile higher compared to my previous location. My body is currently struggling to build more red blood cells.

        I am always on the look out for more sensors because I have such a strong will and high tolerance to pain that no matter how much I listen to my body, it is possible that I go beyond physiologically sufficient levels of stress without realizing it.

    • canute1 Says:

      EF
      The injury during taper must have been frustrating, but I suppose everything can be a learning opportunity. ;)

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