Boredom is a frquently encountered problem with aerobic training. Unlike weight training, where progress in the form of increased muscle size and strength is apparent, gains from aerobics are more subtle: increased endurance and, if combined with diet, lower bodyfat. While the aerobic benefits are certainly desirable, the fact is, aerobic exercise is tedious.
One solution is to vary your aerobic activity. This offers dual advantages in that it not only provides a psychological boost, but you work different muscles while still maintaining an aerobic training zone. Such variety decreases your likelihood of overtraining, a common effect of daily exercise.
There's a problem with varying aerobic exercise, however, and it involves effectiveness. For example, any aerobic exercise done standing will burn more calories and, ultimately, bodyfat than a seated version. Thus, treadmill walking is a better fat burner than stationary cycling. In addition, the more muscles involved in the exercise, the greater the caloric cost. That's why cross-country skiing machines using both upper- and lower-body muscles are top-rated by many experts.
Another consideration is structural or prior injury limitations. In my case an old knee injury precludes using a stair-climbing machine, as it causes my chronic knee overuse condition to flare up. Likewise, people who have lower-back problems should be wary of seated rowing machines, which place an inordinate amount of stress on susceptible lower backs.
In the late 1970s I became a convert to the jogging craze that swept the nation. I did everything right: I ran on a soft surface, invested in an expensive pair of jogging shoes and so on. At first I was gratified by my results. Without altering my diet in any way, I lost fat. My enthusiasm rose with each compliment about my nouveau svelte look.
I gradually increased my daily runs from three to five to eight to 10 miles. I recall running 10 miles in a New York park with my brother on the day he got married (he needed to relax). What I didn't realize was that heavy-volume jogging isn't the correct prescription for a 230-pound bodybuilder. I eventually paid the price with a case of chondromalacia of the knee, a common overuse injury among runners.
Orthopedic physicians report that as many as 75 percent of their athletic injury patients are recreational runners. The problems usually occur in the knees and hips.
One physician once confided that anyone who weighs more than 125 and runs every day is guaranteed to eventually get injured." This points to jogging as being an inefficient aerobic exercise for most body-builders. You have to consider the stress placed on joints in the usual bodybuilding exercises for legs, such as squats. While normal rest between workouts provides sufficient recuperation time, adding something like a daily run or jog to the routine can push you over the injury edge.
With the plethora of machines now available for aerobic training, you can only wonder why anyone would want to jog, other than getting out and enjoying the scenery. If you do decide to jog, don't neutralize most of the health benefits by running near heavy traffic. Studies show that jogging under such circumstances is comparable to smoking a few packs of cigarettes in terms of carbon monoxide ingestion.
If your time for aerobic training is limited; that is, 30 minutes or less, consider using exercises that work larger muscle areas. This provides more oxygen intake, or VO2 max, which is a primary benefit of aerobic training. Or you can increase the difficulty of the exercises you commonly do. For example, increasing the grade on treadmill walking is not only more effective for toning thighs, hips and buttocks, but it also elicits a greater oxygen intake than seated stationary cycling.
A study reported in a 2003 issue of the journal Medicine and Exercise in Sports and Science compared the oxygen intake of a stair machine called a VersaClimber, which has an upper-body component, with those of a treadmill and rowing machine. The results showed that the VersaClimber produced a greater oxygen intake than either the treadmill or rower. This should come as no surprise because the Versaclimber involves standing while using lower- and upper-body muscles simultaneously.
Another study examined whether in-line skating was a suitable alternative to other aerobic exercises and found that if you skate at a speed fast enough to maintain your heart rate at 75 percent of maximum, you'll get aerobic benefits comparable to treadmill walking at a similar intensity.
As for the optimum intensity for aerobics, that depends on your goals. Performing aerobics at a lower intensity more frequently and for a longer time causes a greater fat loss. In practice that means at least four times a week for 30 to 60 minutes at a heart rate of 60 to 70 percent of maximum. You can figure your maximal heart rate by subtracting your age from 220. Then figure 60 to 70 percent of that as your target zone during aerobics.
For endurance and cardiovascular conditioning the most effective method is to gradually increase to a higher intensity, approaching your anaerobic threshold. That's the point of intensity where you slip from aerobic into anaerobic metabolism. The signal is a burning in the working muscles coupled with increased respiration.
The burn is caused by lactic acid because you've exceeded your body's ability to deliver oxygen to the muscles. At that point you're no longer burning fat but instead are relying on blood glucose and glycogen stored in the muscles. Approaching the anaerobic threshold constitutes an overload form of aerobics similar to adding weight on resistance exercises. It conditions your body to use oxygen more efficiently while decreasing the buildup in muscle of lactic acid, a substance that signals muscular fatigue. The net effect is increased endurance and a stronger heart reserve. You even get a spillover effect in your weight training because of increased muscle buffering factors that more efficiently deal with lactic acid produced during high-intensity weight training. In short, you can train faster, taking shorter rests between sets.
There's one caveat, however: Combining aerobics with weight training will interfere with your strength gains. The reasons are too complex to get into here, but you can minimize the effect by not overdoing aerobics (keep it to no more than one hour a day) or by taking a rest day between your aerobics sessions and your weight training.