CYCLING PERFORMANCE TIPS
Anaerobic stress is experienced as the "burn"
associated with intense exercise. Originally it was thought to be
the result of a build up of lactic acid in the
muscle cell, but further studies in subjects with a genetic defect prevents the
production of lactic acid, also experience the same anaerobic burn. Rather than lactic acid,
the culprit is more likely another acidic intermediary metabolic byproduct,
or related to other cellular changes in the muscle cells.
Pushing the athlete's aerobic limits results in changes in the cardiovascular system as well as the muscle cells. These allow pushing even further into the anaerobic zone the next time out.
This study suggested that resistance exercise (weight training) can lead to mitochondrial changes similar to those seen with interval training. This supports the idea of using resistance training to supplement the benefits of interval training.
This study suggests their is a limit to how fast we can improve mitochondrial function. This is a graphic representation of the relationship between exercise volume, performance, and mitochondrial function. We also know that regular aerobic training changes the types and numbers of bacteria in our colon (the microbiome). These bacteria of the microbiome metabolize unabsorbed food material from our diet (generally fiber) and as a byproduct of that metabolism manufacture short chain fatty acids (which can be absorbed from the colon and provide a very modest additional source of energy for the muscle cell). But more importantly they also produce other small molecules that can impact mitochondrial development and energy metabolism.
The traditional teaching has been that aerobic training stress leads to an anaerobic state in the muscle cell which then directly induces adaptive changes in the muscle cell mitochondrial to improve performance. This article suggests the physiology behind these improvements is a bit more convoluted than previously suspected. The article puts forth a good argument that part of the improvement in aerobic performance is indirect via the microbiome. Exercise -> changes in bacteria -> production of molecules will positively influence mitochondrial metabolism and growth.
Your base level of fitness impacts how much additional benefit could be gained from interval training. The 2015 article by Place et al showed the cell changes adapting to interval stress were minimized in the highly trained athlete.
A short intervals is usually an all out effort of less than 30 seconds while long intervals are generally more than two minutes each. Short intervals are not only the most efficient from a time perspective, but are also the most effective as far as results.
In this study short intervals improved one-hour race times the most. It compared 30-second all-out, 5-minute all-out, and 40--min all-out bouts of cycling. In 10 weeks of twice-a-week, effort-matched trials, short interval training was more effective than long intervals in improving mean power output and VO2max (the best laboratory measure of how fast a cyclist can ride or a runner can run over a set distance).
Recreational athletes can train purely with short intervals, but competitive athletes also need to incorporate in their training to adapt to and be able to "ride through" the lactic acid build up that occurs with intervals over 30 seconds in length.
The duration of the recovery phase of easy spinning is related to the duration of the active phase. As the quantity of metabolic byproducts is less with a short interval, the recovery period can be shorter than with longer intervals. That is:
It is not necessary that your heart rate return entirely to normal before the next interval. If you are using a heart rate monitor, you need only wait for your heart rate to drop to 60 or 65% of your maximum heart rate. If you are using perceived exertion (i.e. how you feel), wait until your breathing has returned to it's normal depth and rate.
I couldn't find much data on interval frequency in the scientific literature, but from all I've read, Dr. Mirkin's article on interval training makes the most sense to me. He is a proponent of incorporating some interval stress into every riding day, even on a slow easy day. But also advocates listening to your body as you start each day's ride to provide clues as to how hard you should push yourself. If your legs tell you it time for a break in interval training, get off the bike, it is not a day to ride.
How did we arrive at twice a week intervals? Why not do intervals more frequently? It's interesting how standards develop. A study is done, in this case looking at interval training twice a week. Subsequent investigators use the same frequency for their studies. And without further investigation twice a week becomes the defacto "optimum". The demands of a balanced training program reinforce this frequency. You need a long day at some point during the week to get use to longer times on the saddle, an occasional day of restful spinning to minimize the risk of overtraining and burnout, maybe a ride during the week with friends, a day or two off the bike with bad weather or to take care of family or work responsibilities, and soon an ideal training week has room for just 2 (or perhaps 3) focused interval days.
But Dr. Mirkin suggests that rather than focus on specific interval training days, you incorporate periods of increased exertion (intervals really) into every ride. He came to this conclusion from his personal observation that the more traditional training schedule was not working for him. In his words: "....every time that you exercise intensely, you damage your muscles. You know this has happened when your muscles feel tight, heavy or sore on the next day. To deal with this soreness, we (he rides a tandem) followed a program of racing as fast as we could three times a week (Tuesdays, Thursdays and Saturdays). On the other four days we would recover by riding 20 to 30 miles slowly, at about 10 to 11 miles per hour. But something was wrong with this program because we were gradually losing our ability to ride as fast as we had in a previous year. We were doing too many junk miles on our four recovery days each week."
He decided that fewer rest days were actually better for their training, and found that when he eliminated rest days (at least a regimented number per week) he actually had less overall muscle discomfort. He also speculated that every ride should include some stress and the only reason to do extra easy miles was to acclimate the riders' bodies (butts and shoulders) to prolonged time on the bike and "....Slow riding or running does not increase your ability to take in and use oxygen and it does not make your muscles stronger."
He changed his training - not more rest, but more intervals, riding short distances fast enough to be very short of breath, then slowing down until he recovered his breath. To quote: "Intervals were worked into every riding day. Maybe 50 - 100 pedal strokes (which normal cadence is about a minute). And this number was based on how the legs felt. Not an arbitrary number to be mindlessly achieved. On some interval days, we would do 50 pedal-stroke repeats, resting between each long enough to get our breath back. Other days we would do 100 or 150 pedal stroke repeats. We never plan to do a fixed number of intervals. Instead we would stop the intervals as soon as our legs started to feel heavy or stiff, or when our legs did not recover and continued to feel tired a minute after finishing a fast interval."
No longer was there a mandatory one or two rest days every week but instead resting based on how the legs felt. "....your leg muscles usually start to feel better and you can ride fast after you have warmed up. However, if your legs do not feel fresh after you have warmed up for more than 15 minutes, you should just take the day off. So some weeks this might lead to more days off the bike, and other weeks riding everyday might happen."
With his approach the duration and intensity of intervals change from day to day. Even on a traditionally long slow distance ride, intervals (hills count) were incorporated. Not a focused period of time within the ride, but randomly adding a fartlick or mini-interval. Even on a rest day of planned easy spinning there would be mild tempo changes throughout the ride.
This approach means you do have to listen to your legs. You get the benefit of adding cardiovascular stress to every ride but the cost is adding the additional complexity of assessing your riding status each day, backing off, or stopping completely, if the legs are tired after the warm up. No longer the inflexible 'I must ride' approach to interval training. My guess is that a lot of us are already varying the tempo of our rides. How is Dr. Mirkin's approach different?
Find a road where little hills come one after another. Attacking these humps can be a peak experience -- like riding a roller coaster. You fly up one side, blast down the other and use your momentum to conquer the next rise. But if you use improper technique, you can get bogged down. Instead of grinning, you're grinding. You churn up, coast down to catch your breath, then bang against the next wall. Rhythm is everything. Here's how to keep yours on successive climbs:
High Intensity Training (HIT or HIIT). High Intensity Training (HIT) is an interval training adaptation that is used:
Heart Rate Intervals. If you use a heart rate monitor, you can key intervals to your maximum heart rate. Ride your intervals at 80 to 90% of your maximum heart rate and spin easily until your heart rate drops to 60 to 65% of maximum.
Endurance Ride Intervals. You not only get credit for some interval work but can decrease your total riding time on that long endurance ride by adding some interval training. Here are two tricks to consider:
Watch for opportunities. Get out of the saddle and accelerate away from stop signs, over short hills, out of turns or past the lair of a troublesome mutt. Don't script these pickups. Instead, do them when the terrain or situation asks for it. To do a pickup, choose a cog 2-3 teeth smaller (higher gear) than you'd normally use for the situation. So, if you'd usually roll over a rise in a 53x21-tooth, use the 53x19. Don't sprint all-out. That's not the purpose. Instead, simply stand and wind up the gear for 10-12 seconds. Effort should be about 80% of a flat-out sprint. You shouldn't be panting after you sit down. A few deep breaths should get you back to the ride's baseline effort. You'll be amazed at how much better you feel on longer rides when you relieve saddle pressure and treat your legs to these brisk efforts.
Pace line Intervals. These training techniques simulate what happens in road racing. They're great workouts and guaranteed monotony-busters as well. Warm up and settle into a single pace line moving at a moderate speed. Then try one of the following:
The science tells us that lack of recovery (riding at lower training intensities) not only fails to provide a return or benefit benefit from extra riding time, but might be sacrificing overall performance.
A reasonable balance might be 20% of your riding time at a moderate to high intensity pace (perceived effort of 6 - 10 or 80% MHR) and 80% at a PE of 4 or less. For most of us, the challenge will be to keep our slow and easy rides slow and easy. My guess if you will probably have to work to keep that HR down.
Recovery is important, but you do need to keep up those weekly miles. You cannot just focus on intervals and allow total total weekly exercise volumes (the total number of hours on the bike per week) fall off without impacting endurance performance (time to exhaustion riding at 75% VO2max). It is a combination of intensity of exercise (best achieved with intervals) and total time on the bike (from the long slow distance rides) that determines overall competitiveness or performance in an event or on a longer ride.
I like the Dr. Mirkin's attitude for interval training.
The following is a possible scenario:
Include short non traditional intervals into the remainder of your rides. Not intense effort, just an increase from baseline effort.
We know from weight-training studies that the first set or two provides the stimulus for most of the improvement gained during multi-set workouts. If you do five sets of bench presses, for instance, much of the benefit occurs during the first set. The second set stimulates most of the remaining improvement possible from the session. The final three sets do relatively little.
It's likely the same applies in interval training with the first set (or two) of intervals providing the bulk of the benefit and diminishing returns from additional sets. So if you're pressed for time, just got an urgent call, or just in a hurry to get off the bike, take a break after those first few intervals and come back fresh, ready to give 100%.
improve endurance performance.
Studies on the benefits of interval training for endurance performance show a wide range
of results as the studied groups are so diverse - from untrained riders to elite athletes.
In regular riders, a 5 to 10% improvement in total time to exhaustion at
an endurance pace (60-80$VO2max)was not unusual after adding intervals to a training program. And
studying sedentary individuals produced even more impressive results.
First article: (abstract, full article) - approximately 15 min of intense exercise over 2 wk (a pretty short time) DOUBLED endurance capacity (exercise at ~ 80% VO2max) in active individuals.
Second study: (abstract, full article) - in well trained competitive cyclists rather than recreationally active adults. Endurance performance in a 40 km time trial improved after interval training (a minute off of a 57 minute result). The improvement appeared to be from the muscles increased ability to buffer the acidic products of metabolism rather than any change in the riders' VO2max.
A third study, a review, supported an improvement in endurance performance without a change in VO2max. The authors indicated an increased "tolerance" for fatigue from an increase in the efficiency (using less energy per unit of distance covered).
And finally, In this study, the group assigned to 30 minutes of steady riding 3 times a week increased their time to exhaustion by 64%. But training with intervals, 3 times a week, doubled the benefit with a 129% improvement in time to exhaustion! Twice as much physiologic improvement for the same amount of training time.
For those interested, this is a great summary article on the physiology of interval training with a short section on the physiology behind improving endurance performance.
And for more on improving endurance riding.
Personal performance. Here the answer is a definite "YES", especially for interval training. The risks of too much training (over reaching and over training) are well established in the training literature. This study suggests the reason is mitochondrial (the ATP producing powerhouse of the cell) dysfunction.
This is a graphic representation of the relationship between the amount of intense interval type training, performance, and mitochondrial function.Interestingly, this degree of excessive training also affected the athlete's metabolic health, impairing their glucose tolerance. They went on to study glucose metabolism in world class endurance athletes and found it was also impaired compared with a matched control group.
Cardiovascular. If you are worried about your heart or cardiovascular system, the answer is fuzzier.
This study using accelerometer data rather than self reported interviews and questionnaires (which risk being biased.) The authors found no evidence of a threshold or plateau in an inverse association between both moderate and vigorous physical activity and a lower incidence of cardiovascular disease. Their findings suggest that long term physical activity is not only associated with a lower risk for of CVD, but the greatest benefit is seen for those who are active at the highest level.
This article in the NYT specifically stated that without a family or personal history of heart disease, there was "... no evidence there is a level of exercise that is dangerous or too much for a normal, healthy person." Although this is generally true for interval type training, there is evidence that when we are talking about exercise volume (endurance training and competing) there is an upper limit. The curve of benefits versus exercise volume doesn't just plateau but is likely to drop off as the extremes are reached . A few examples:
How do you reconcile these findings? Assuming you have no family or personal history of cardiac disease or conditions, the cardiovascular risks appear to be related to repeated stress at the ultra-endurance event level. There is little evidence that short term, high level exertion such as 30 to 60 second intervals is harmful, but also no sound evidence that intervals longer than this add any cardiovascular fitness benefits. Pushing your training (within reason) is not harmful with cardiovascular risk appearing only as you move to the ultra event level.
All cause mortality. Findings here mirror to a degree the findings with CV disease. Benefit at lower training volumes but evidence for harm at the upper extremes. One study of Harvard alumni found a lower death rate (mortality) among men expending as few as 200 Calories per week in exercise versus those leading sedentary lifestyles, but when they regularly pushed their limits with over 4000 exercise Calories per week the death rate began to rise again.
Immune system.Several studies have suggested a decrease in immune system competence with intense training (cycling 300 miles per week for 6 months or 2 intensive sessions of running per day for 6 days). This has to be balanced with the overwhelming evidence that a moderate cycling program actually stimulates and improves the immune system.
Musculoskeletal. Musculoskeletal injuries are known to all of us who exercise and participate in aerobic sports. Overuse leads to injury. And the cure is to listen to your body, and if it hurts when you are using it, decrease your activity level.
It seems wisest to chart a course with a balanced approach. Let your body tell you when it is time for an extra recovery day.
Add intervals of 3 minute duration - repeat 5 times - to your program (ridden at a pace a bit faster than your speed in a time trial and a lot more intense than your century pace). Then spin easy for 3 minutes between each effort. Twice a week. And never back to back days. For variety, longer intervals are also effective - perhaps 10 to 20 minutes at your time trial intensity with two or three repeats.
The following question from a reader suggest that riding with weight is another alternative (just like riding into the wind) to add intensity to your training, simulating an increased load and thus generating a training response. I've had similar comments from other readers.
Q.I was wondering whether you know something about the following: I am riding about 150 pretty fast miles a week, usually with a 12-15 pound backpack (because it is my commute and I carry a laptop and clothes etc.). Sometimes I ride without the backpack and noticed that I am considerably faster. While this is of course not surprising I was wondering whether 'riding with weights' could actually be a useful training technique -- I couldn't find any information about this. - MS
A. Mike, as I mentioned above, added weight (speed remaining the same) is a way to add a stress to your muscles and CV system, which will adapt, and then you will be able to perform more effectively when unburdened. It is the same reason one would weight train as part of a program, or train on a clunker and then get out a titanium frame for that important ride. Dick