By Coach John Hughes
Intense exercise produces different physiological benefits than moderate exercise. Here’s why you should incorporate the appropriate types of exercise for you at the appropriate times of the year.
Your muscles atrophy over time as you age. You have two different types of muscle fibers: slow-twitch, which fire slowly and have great endurance, and fast-twitch IIa and IIb, which fire explosively when you need power. You differentially lose muscle mass in the fast-twitch fibers because as you age you tend not to do activities that require a lot of power. (Slow and fast refer to the firing rate of the muscle fibers, not your cadence.)
You recruit muscle fibers progressively. When you ride at a moderate conversational pace you are using your slow-twitch fibers. When you exercise harder, e.g., climbing a hill, you recruit your fast-twitch IIa fibers, in addition to your slow-twitch fibers. When you exercise really hard, then you are also recruit your fast-twitch IIb fibers.
Your heart is a muscle, and as it ages the muscle fibers atrophy and your heart pumps less blood per beat. Your respiratory muscles also atrophy as you age. Your cardiac and respiratory muscles also lose elasticity.
When you exercise hard, you increase the demands on your slow-twitch, fast-twitch, cardiac and respiratory muscles, all of which then maintain more fitness. Your cardiac and respiratory muscles also maintain more elasticity.
Your enzymes decrease. Your muscles get energy through different processes: aerobic metabolism of fat, aerobic metabolism of glucose, anaerobic metabolism of glucose and the adenosine triphosphate – phosphocreatine system. Each of these processes requires different enzymes. Further, the amounts of enzymes produced for the different energy systems result from how much you use that system. If all you do is moderate exercise, your body only produces enzymes for aerobic metabolism, primarily the aerobic metabolism of fat as well as fewer enzymes for the aerobic enzymes of glucose. The result is that when you have to climb a hill, you have fewer fast-twitch IIa fibers to do the job and fewer enzymes to produce power for those fibers.
Through exercise, you can slow the loss of power from the fast-twitch muscles and the loss of enzymes.
Benefits of Training with Intensity
Exercising with intensity has the following physiological benefits, depending on the intensity:
1. More economical use of time.
2. Improve your pedaling economy.
3. Improve your cycling.
4. Repair effects of aging on your muscle cells.
5. Raise your anaerobic threshold.
6. Slower decline in your VO2 max.
More economical use of your time.
For aerobic exercise, the American College of Sports Medicine (ACSM) recommends accumulating either a total 150 to 300 minutes of moderate exercise per week or a total of 75 to 150 minutes of vigorous exercise per week, or a combination. You could meet the ACSM’s recommendations with vigorous exercise in half the time it would take for moderate exercise. Moderate cardio exercise is the most important; however, you can substitute appropriate intense exercise time for some of the moderate exercise time.
Anti-Aging: 12 Ways You Can Slow the Aging Process is your comprehensive guide to aging well. The 106-page eBook is available for $14.99
Anti-Aging includes an annual plan to put together all six of the aspects of aging well: cardiovascular exercise, intensity training, strength workouts, weight-bearing exercise, stretching and balance. The book concludes with a chapter on motivation.
The book describes the physiological changes that take place as you age, how to assess your current fitness and the training principles that apply to older roadies.
Coach Hughes incorporates the latest research and most of it is new material not published in his previous eArticles on cycling past 50, 60 and beyond.
Anti-Aging: 12 Ways You Can Slow the Aging Process gives you the tools you need to slow the inevitable decline in your health and fitness.
Anti-Aging describes the physiological changes that take place as you age, how to assess your current fitness and the training principles that apply to older roadies.
Improve your pedaling economy.
Your slow-twitch muscles and fast-twitch IIa and IIb muscle fibers don’t naturally all fire at the same time. When you exercise at maximum intensity, i.e., sprinting, you’re demanding as much instantaneous power as you can get from all of your muscle fibers firing. The result is improving the coordination of the sending of signals from the individual nerves to the individual muscle fibers. This is the same as dialing in the timing of the individual cylinders in your car engine. This means you increase your pedaling economy without using more fuel or oxygen.
Because sprints improve your pedaling economy, they will benefit most riders — from casual endurance riders to racers. Start with very small doses, i.e., two or three 20- to 30-second sprints in an endurance ride with plenty of recovery between each. To continue to improve, lengthen the sprints by 10 to 15 seconds and add another sprint or two.
Improve your power and speed.
In addition to improving your pedaling economy, intensity workouts will increase your power and, as a result, increase your cruising speed. You do this by training in the Sweet Spot.
The harder you ride, the more you overload your body, which stimulates more adaptation. However, the harder you ride, the more recovery you need both between hard efforts and between hard days. The need for more recovery limits the total volume of hard efforts. The Sweet Spot is the range that balances how hard you ride with the need for recovery to produce the most total overload on your muscles.
Repair effects of aging on your muscle cells.
Aging damages the cells in your muscles, which is especially severe, because they do not regenerate easily. They become weaker as their mitochondria, where energy is produced energy, diminish in vigor and number. Researchers at the Mayo Clinic tested different training protocols on two sets of participants. One group was age 18 to 30 and the second set of participants was age 65 to 80. The age groups had approximately equal numbers of men and women. The participants did not exercise regularly before the study.
The study found that intensity training increased the number of mitochondria where energy is produced but neither moderate cardio or strength training increased the number of mitochondria.
Raise anaerobic threshold.
Your anaerobic threshold is the point at which the production of lactate significantly exceeds the body’s capacity to clear the lactate. When you exercise slightly above your anaerobic threshold, you improve your muscles’ capacity to metabolize lactate as a fuel, thus increasing your anaerobic threshold. If you already have a high AT relative to your VO2 max, then you may not see any increase in AT.
Increase VO2 max.
VO2 max, also called aerobic capacity, is the maximum amount of oxygen that your working muscles can utilize. Physiologists agree that declining VO2 max as you age is the chief cause of declining performance. You can’t deliver as much oxygen to your working muscles. Decline in anaerobic threshold is a distant second and loss of economy is third. According to one study of fit male cyclists, VO2 max declined by 30.5% from age 60 to 69 and a further 15.6% from 70 to 79. The reason for the loss is simple. As riders age, most stop doing the intensity training necessary to slow the decline in VO2 max. Continuing to include high intensity training in your riding results in about half as much loss per year of VO2 max as just doing endurance training.
Physiologically the decline in VO2 max is primarily due to the decline in your body’s ability to deliver oxygen to your working muscles. How much oxygen your body can deliver is the result of stroke volume (how much oxygen your heart delivers per beat), specifically the size and contractility of the left ventricle. The left ventricle is a muscle and like any muscle that is not worked hard the power of the left ventricle declines. This loss is greater in men than women. Decline in maximum heart rate may also affect VO2 max; however, studies of this yield inconclusive results.
My new eBook Anti-Aging: 12 Ways You Can Slow the Aging Process will be published next week. It describes in detail the pros and cons of gauging intensity by Rate of Perceived Exertion, Heart Rate and Power. It explains how to determine your anaerobic threshold (AT) or your functional threshold power (FTP) and includes a spreadsheet for you to calculate your own training zones. It explains how to do five different types of intensity workouts depending on your goals. It includes a year-round program of how to incorporate different types of intensity workouts into different phases of your training year.
Check out my book, Anti-Aging: 12 Ways You Can Slow the Aging Process.
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Coach John Hughes earned coaching certifications from USA Cycling and the National Strength and Conditioning Association. John’s cycling career includes course records in the Boston-Montreal-Boston 1200-km randonnée and the Furnace Creek 508, a Race Across AMerica (RAAM) qualifier. He has ridden solo RAAM twice and is a 5-time finisher of the 1200-km Paris-Brest-Paris. He has written nearly 30 eBooks and eArticles on cycling training and nutrition, available in RBR’s eBookstore at Coach John Hughes. Click to read John's full bio.