HEALTH & FITNESS ARTICLES
Maximize Your Cardio
You probably have a love-hate relationship with the next level of cardiovascular training: aerobic capacity or VO2max training. It is heart-pumping hard exercise. It could leave you feeling euphoric, but it is not for the faint of heart. Fortunately, you will reap many rewards for spending a relatively small amount of time on VO2max training. By devoting only about 8% of your training time to VO2max training, you will significantly upgrade the work capacity of your cardiovascular system. Your heart will begin to pump more blood with each beat (increased stroke volume), your resting heart rate will decrease, and your metabolism will increase. Although any type of cardiovascular exercise strengthens the heart to some extent, VO2max training, in particular, improves the efficiency of the cardiovascular system. It enables the body to absorb more of the oxygen coming in and convert it to high levels of energy. The net result is decreased risk for cardiovascular disease.
During VO2max training, you move one step up the intensity scale. To stimulate cellular adaptation, you work at 70% of your VO2max. To increase your lactate threshold, you work at 80 to 85% of your VO2max. To increase your VO2max itself, you work for short periods at 90-100% VO2max intensity. Hence, your VO2max is not necessarily a fixed number. It may increase or decrease depending on how your train.
Also, understand that VO2max refers to a two step process concerning oxygen intake. The first part is the maximum amount of oxygen your body could consume at one time. The second part is how much of that consumed oxygen gets delivered to working cells and used to produce energy. In other words, simply consuming large volumes of oxygen alone does not result in increased energy production. You must train your body to efficiently process the oxygen at the cellular level. Hence, cellular adaptation and lactate threshold training are important in conjunction with VO2max training to prepare the body for increased oxygen intake and absorption.
Subjectively, VO2max training should feel “hard.” Get a medical clearance before starting this high intensity training. If you train with a heart rate monitor, work at the slowest pace that brings you up to 90% of your maximum heart rate. A faster pace will elicit your maximum heart rate, but it might put too much stress on your body and require a longer recovery period. Your goal is to work aerobically as hard as possible and minimize anaerobic energy production. A popular method for training at VO2max intensity is interval training. Interval training divides your high intensity work into short periods of hard work mixed with recovery periods of easier work. This keeps the high intensity work from becoming too stressful on your body. In addition, to avoid overtraining, limit your VO2max training to no more than 8% of your total volume for the week, and schedule 1 to 2 interval sessions for 3 to 4 weeks then replace with low intensity training for 1 to 2 weeks before resuming.
Note that the interval training to increase lactate threshold discussed in Part 2 is different from interval training to increase aerobic capacity. Intervals appropriate for lactate threshold training are mini tempo runs, or “cruise” intervals. They are longer in duration with shorter rest periods than aerobic threshold intervals. Lactate threshold training is a lower intensity method stressing aerobic endurance over aerobic capacity. For example, lactate threshold training might involve 4 sets of 1 mile runs with 1 minute walk breaks between run intervals. Aerobic capacity intervals for the same 4 mile run might involve 8, half mile runs at a faster pace with 2 minute walk breaks in between intervals.
Find a work to rest ratio that best meets your goals such as 1:2, 1:3 or 1:4. For example, accelerate for 1 minute then perform active rest exercise for 2, 3 or 4 minutes depending on your goal. Include at least a 5 to 10 minute warm up and cool down at the beginning and end of the interval portion. Consider the total length of the session. Beginners should start with longer work to rest periods. For example, warm up for 5 minutes, perform 5 intervals at a 1:3 ratio for a total of 20 minutes, and then cool down for 5 minutes. The total length of the session is 30 minutes. More advanced athletes might work hard for 3 to 5 minutes and actively rest for about the same amount of time. Work hard but not too hard. Work at a pace you could sustain for about 10 to 15 minutes. Decrease the rest period before increasing speed. Here, the goal is to increase maximum aerobic capacity and avoid too much anaerobic energy production that comes from high speed.
Listen to your body. Aerobic capacity (VO2max training) is demanding. Your body will tell you if you did too much. If you feel sore beyond one day after exercise, you probably worked too hard and need to cut back intensity for a session or two. If you do not feel sore, but you are tired and cranky, that is also a sign you are doing too much too soon. Overtraining will not help you reach your goal faster and may lead to illness or injury.
1. Work at a “hard” pace which equals to about 90% of your VO2max. You should be able to say a few words, but you will be breathing hard. This is a step up from the “comfortably hard” pace required to increase lactate threshold. However, do not work so hard that you feel intense burning in your muscles. The burning feeling is a sign of anaerobic energy production; the goal of this training is to increase aerobic capacity.
2. Keep the duration of threshold training to about 8% of the total cardiovascular training volume for the week; runners, limit interval volume to 8% of total volume or 10,000 meters whichever is less.
3. Find a work to rest ratio that fits your fitness level and goals such as 1:2, 1:3 or 1:4.
4. If outdoors, perform intervals on flat, dry terrain on a clear day. Interval VO2max training is great on treadmills and in spin classes since many machines allow you to program your workout and keep your speed and time consistent.
5. Eat healthy, high energy carbohydrates such as apples, bananas, and whole grain toast at least an hour before these workouts. Aerobic capacity training is demanding and requires a lot of high quality energy.
6. Limit periods of interval training to about 3 to 4 weeks then take a break by doing lower intensity, lower volume training for 1 to 2 weeks. Periodizing your workout program helps prevent overtraining.
Daniels, Jack. “Incorporating Sport-Specific Skills into Conditioning: Distance Running,” within High-Performance Sports Conditioning, Bill Foran ed., Human Kinetics, Inc. 2001.
This article was provided by Free Movement Fitness Inc.
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