Topics: A follow up on muscle glycogen from last week, Base training program, Interval length, Persistent numbness in left foot
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A follow up on muscle glycogen from last week
There are tons of procedures and studies out there how to replenish muscle glycogen after exercise. But is there any way to do so [just like to refill liver glycogen constantly] while exercise? Or is it doable only while resting? And if yes, why? What’s the hindering point?
Do I comprehend it correctly, as soon as those 300-450 grams of CH are depleted in the muscles, my training/race will be supported only by fat, protein and liver glycogen [blood sugar]?
Pamela Hinton says:
There is another more fundamental reason that muscle glycogen is not stored while riding. During exercise, hormones (e.g., insulin) that promote storage of carbohydrate as glycogen or fatty acids in body fat are suppressed. By contrast, "catabolic" hormones (e.g., epinepherine, cortisol) that mobilize stored fat and glycogen are increased. These hormonal responses make sense because it would be counterproductive to store either carbohydrate or fat when these fuels are needed to supply ATP for muscle contractions. A similar phenomenon occurs at the level of the muscle cell. When the cell is in a low-energy state, i.e., low ATP:ADP ratio, the metabolic pathways involved in the synthesis of glycogen from glucose are suppressed, as are those involved in fat synthesis and storage. At the same time, the pathways that produce ATP from glucose or fatty acids are activated, increasing the energy available to the cell. So, regardless of how much glucose is ingested and absorbed while riding, it will be used to fuel your muscles not stored as glycogen.
Scott Saifer adds:
In trained individuals the insulin reduction and glucagon increases during exercise are extremely blunted. Gyntelberg at al (1977) showed that in untrained, insulin drops by about 60% after an hour of exercise at 60% VO2max ( 70% maximum heart rate), but only by 30% in trained individuals. Similarly for glucagon: It more than doubles during exercise in untrained and rises a mere 20% in trained individuals. At lower exercise intensities, the response is even smaller, and there's no reason to expect that at low enough intensity, a rider couldn't experience a full insulin response and glycogen storage. The more trained the athlete, the higher the power that can be produced without so reducing insulin as to make glycogen storage impossible. It is wrong to think of hormones as on-off switches. They rise and fall incrementally, causing incremental changes in the systems they regulate.
I suppose it's an open question which effect (glucose flow into powering the exercise or hormone shifts) dominates the control of glycogen formation. We know that riders who are close to fully glycogen depleted bonk, and that riders who do Brevet's can essentially ride forever without bonking. That suggests to me that they must either be not touching glycogen at all, or forming and using it constantly.
Base training program
I am preparing for my first competitive cycling season and I am trying to build up an aerobic base over the winter. I have spent a tone of time researching the internet for how to structure a base program and almost everything I have come across suggests long steady Zone 2 riding. Some sources seem to promote doing only zone 2 riding for the duration of the base period, as anaerobic training will break down the physiological changes made doing base training - while others seem to suggest a combination of LSD riding days with one racy ride per week and at least one day of intervals. My question is, which way is correct? How should I be structuring my 10-12 hour training week during the base period? Purely Zone 2 riding? Or a mix of Zone 2 rides with more intense riding days as well? And would adding weight training (anaerobic) to my program negate my aerobic base gains? I want to make sure I'm improving heading into the season without over or under training.
Thanks in advance,
Scott Saifer says:
Neither way is correct. Wenzel Coaching recommends all zone 2 during base for most riders, and our clients do quite well. (For instance, we averaged more than 25 podiums per month last year), so we know all-zone-2 works. I also know of people who incorporate more intensity into their off season and do fine as well. There are some advantages to each method, and some disadvantages.
One disadvantage of the all-zone-2 base method is that when racing season comes around, a rider on this type of plan has not done any hard riding in several months. The first few weeks of racing going hard really hurts, and since their anaerobic endurance is detrained, they blow up quickly. Both of those effects pass within 3 weeks or so. Riders on this sort of plan need lots of reassurance: "Your legs will come around. Don't worry".
Hard riding does NOT undo the base development done by easier rides, but it does make riders tired. The major issue is overall stress level and recovery ability. If you have the ability to ride hard on some of your 10-12 hours and still recover well to use up all those hours, there's not much disadvantage to harder riding. For people who have stressful non-cycling lives however, I have seen consistently that riding harder greatly increases the chance of burn-out before the season arrives. The number-one rule of base training is to listen to your body: go train when you feel absolutely great. Go shorter and easier if you feel anything but awesome. If you can mix in the higher intensity rides and still feel awesome on most of your rides, go ahead and do it. If higher intensity leaves you feeling draggy for a day or two after, skip the intensity and go with an all-zone-2 plan.
Strength training done appropriately is a good supplement to your riding program. It can drive he conversion of type IIx (untrained fast-twitch muscle fiber) to IIa (aerobically trained fast-twitch). Type IIa fiber is what gives you power for longer, harder efforts like climbing or riding a break-away or TT.
First thank you for the quick response! Your answer to my question was very helpful and answered most of my biggest questions regarding structuring a base program. A few follow up questions: If I'm not planning on racing until April, how far in advance of my first race should I shift from base to high intensity training to avoid the "heavy legs" once racing begins? And then how soon before The race should I taper my training?
Also, regarding how to implement strength training appropriately, you mention conversion of IIx to IIa - does this mean is should be doing endurance type lifting of lower weights and extremely high reps to train fast-twitch muscle fibers? Or be gradually increasing weight and decreasing reps to build mass? as the latter seems as though it would be training slow-twitch muscle?
Just some background info:
Age: 24 years
Current base phase training schedule:
Monday: Spin-Ups and one legged pedaling - 60 minutes in the gym (step-ups, squats, leg press, plans, side planks, back extensions)
Tuesday: 45-1hr unstructured ride or day off
Wednesday: 2-3 hours Zone 2 base miles
Thursday: Spin-Ups and one legged pedaling - 60 minutes in the gym (step-ups, squats, leg press, plans, side planks, back extensions)
Friday: 45min-1hr easy spinning / recover ride or day off
Saturday: 2-3 hours group ride, varied pace over varied terrain, or Zone 2 base miles
Sunday: 2-3+ hours Zone 2 base miles
Thanks in advance,
Scott Saifer says:
If you want to be really on form for your first races, do all zone-2 until three months before the racing starts. Then do a month that includes zone 3, a month that includes zone 4, and a month of hard group rides and race simulations. That will have you ready to start racing with your racing legs already on. The downside of this plan, particularly for newer racers is that once one starts doing zone 5 work every week, the peak clock is ticking. Newer racers will usually have skills and tactical issues to work out in the first few weeks of racing, so I like to use the first few races to sharpen fitness and skills at the same time. That way the physiological peak overlaps more with the period when skills and tactics are adequate to generate good competitive performances.
You can challenge and therefore train fast twitch fibers with either short sets and heavy weights, or longer sets with moderate weights. The key is to get close to failure so that the brain is looking for the last few fibers to recruit to complete the workout. I prefer longer sets with moderate weights to reduce the chance of injury. The research says however that you won't add mass if you combine strength training with endurance training on the same muscle, no matter how heavy you lift.
Be careful with the one legged pedaling. The research in that area suggests that if you find one-legged pedaling difficult, doing it will help improve your pedal stroke, but that once you are good at one-legged pedaling, continuing to do it will slow the further refinement of your two-legged pedal stroke.
Your current weight puts you in the all rounder range, closer to the sprinters and TT riders than the guys who do well in the hills. You haven't said what your goals are, but if longer hills play a role in many of the races you'll attend, losing about 5 pounds will serve you well. If the races on which you will focus are true climbing races, losing 10-15 pounds would be better. Don't lose more however.
In December my schedule will remain the same, except my Tuesday and Thursday sessions will be dedicated to zone 3 intervals. Everywhere I look it seems the recommendation is to do 3x10 at zone 3, with 5 minute rests between intervals, or something similar. However it seems to me that this is not the most efficient way to do intervals.
It seems it would be better to get a good warm up, then hit my zone 3 power number and hold it as long as possible. When I can no longer maintain the target power output, I will ride zone 1 power until I feel recuperated enough to do another zone 3 interval. I will again maintain zone 3 power for as long as possible. I would repeat this process until my hour was up, or I could no longer achieve the target wattage.
Is there something wrong with this approach? It seems to me it is the most efficient way of doing intervals and will lead to the greatest adaptation.
Thanks so much!
Scott Saifer says:
One might think, given how authoritatively some coaches assert their particular interval program structure that there was actually some research that had confirmed particular interval lengths or precise heart rate zone endpoints. Unfortunately that is not the case. No one has ever compared 12 minute intervals to 10 minute intervals, or 8 minute rests to five minute rests. This lack of testing is based on the perception among exercise scientists and more thoughtful coaches that it really can't make a difference.
I do sometimes assign a workout that sounds like what you are describing, mostly as a way to develop toughness by suffering through a hard session. Have you actually tried it? I expect that if you go long enough in zone 3 that you cannot continue, you're going to need more than a few minutes recovery to be able to do another interval of significant length, and that later in your interval you are going to hurt more than necessary for the training benefit you'll get from that workout. In other words, you could get a similar physiological benefit by doing shorter intervals with less suffering.
Persistent numbness in left foot
I have been riding and racing off road and road TTs for over twenty years now, beginning as a typical off-the-back beginner but progressing to decent Masters Expert through the years. I am now 52 years old, 6'1", and about 182lbs. I ride about 4000 miles per year and do a lot of high-intensity interval work both indoors and out.
As a respectable athlete in various sports since my youth, I have always been heavily right-handed/right-sided and conscious of a modest strength difference between the left and ride side of my body. However, in the past year I have developed a subtle but persistent numbness in my left foot, concentrated in the toes and ball of the foot. In addition, when totally on the rivet on a hard climb or time trial, my left quad loads up and fatigues significantly sooner than my right. It has, essentially, become the weak link in the chain and has begun to markedly affect my performance. It actually now feels like my strong leg is dragging the weak leg around through the pedal stroke.
Last winter in the off-season I blasted my legs in the weight room, attempting to "wake up" the muscles of the lazy leg. The presses, extensions, and step-ups seemed to help a bit but only temporarily. If I totally turn myself inside out on a time trial, the weak leg will feel slightly livelier and the numbness will subside a bit, but only for a day or two before it then returns. As I sit and write this, there is a subtle tingling in my toes of my left foot. I should also add that on cool days the left will go numb considerably sooner or at higher temperatures than the right.
I have been diagnosed with a slight leg length discrepancy (left is shorter), which causes me to drive my right hip deeper into the pedal stroke. Thankfully, however, up until now I suffer no pain or discomfort on any of my bikes, road, mountain, or TT.
I guess the bottom line is: should I seek the opinion of a specialist, thinking that i might have a serious circulation or nervous problem developing? Or is this just another one of those age-related ailments that I keep denying is happening?
Any suggestions you can offer would be most appreciated.
Steve Hogg says:
By all means seek medical advice but a solution to your problem may simple. A common reason for the problem you have is overextension of the left leg. It is very likely that you are stabbing at the pedal late in the pedal stroke. This will load up the area of the foot above the pedal and often fry the quads as well. Usually at the heads of the quads immediately above the knee.
In your case there are 3 potential reasons that may cause this in any combination.
1. Your shorter leg hasn't been compensated for with a shim. Or the shim stack you are using is not large enough.
More info regarding that here.
2. That your seat is too high. This is VERY common. If the seat is too high, next to no one will sit symmetrically on the seat and equally overextend both legs. The vast majority will protect one side by dropping the hip on that side which of course, causes the other leg to overextend even further. You say that you are very right 'centric' (if there is such a term) which makes this portability even more likely. More info about this here and here.
3. That the absence of optimal foot correction in the form of arch support and wedging is causing you to overly favour the right side with the same consequences as in 2. More about this can be found here.
Lastly, have a look at the sole of left foot underneath the MTP joints (base knuckles of toes). If there is any callousing or thickening of the skin underneath the 2nd, 3rd and 4th MTP joint, that likely indicates that they are sitting lower than they ideally should and that the resulting nerve compression plays at least a part in your problem. If so, the solution is a decent metatarsal pad just behind the MTP joints to raise and separate them.