We've all heard that "Too much of a good thing can be bad for you," but does this apply to cardiovascular exercise? After all, scores of studies have shown that cardio workouts are a great way to burn calories, tone your muscles, and strengthen your heart and lungs. It doesn't seem unreasonable to think that the more cardio you do, the more fit you'll become, right? Well, this isn't always the case. Believe it or not, it is possible to do too much cardio, but the factors that determine how much is too much will vary from person to person. Here are some of the factors to consider when figuring out how much is too much cardio:
- Current fitness level
- Overall health status
- Body type
- Intensity of the workout
- General lifestyle (sedentary or active)
- Diet (what and how often you eat)
- Sleep habits (quantity and quality)
- Fitness goals
For the reasons listed above, what may be considered too much exercise for one person will be perfectly fine for another. In addition, if you improve your fitness level over time, you may be able to handle a higher level of workout intensity within six months to a year versus what you can handle right now.
Although exercise benefits us in several ways, the body doesn't initially perceive it as beneficial. As a matter of fact, your body responds to exercise the same way it would to a negative stressor; it releases certain chemicals that are created to respond to bad stress, immediately shifting into defensive mode to maintain the body's sense of equilibrium (i.e., homeostasis). This puts an extra load of stress on the body, and if you don't take the time to adequately recover between workouts, excessive exercise will begin to produce negative physical and mental effects.
In fact, too much cardio exercise can actually cause muscle atrophy, which is a decrease in muscle mass. Stories abound of avid runners whose calf muscles actually begin to waste away due to excessive training. You definitely want to avoid this type of outcome, and the best way to do so is by applying moderation to your workouts. As with most other disciplines, the best approach is to be somewhere in the middle of the curve by avoiding the extremes on both sides. Too much exercise--or too little--will produce negative consequences.
So how can you tell when you've overdone it? While it's normal to feel a little sore or tired from an intense workout, what are some signs that you've gone too far, and may need to reel it in a little? If any of the following scenarios ring a bell, you may be overdoing it with your cardio workouts:
- Are you experiencing poor quality sleep, or do you still feel tired after getting more than eight hours of sleep a night?
- Do you feel an undercurrent of fatigue throughout the day?
- Have you been getting sick more frequently than usual?
- Are you experiencing a lower quality of physical performance when you do work out? In other words, has your stamina, strength, endurance, etc., decreased?
- Has it been difficult to recover between workouts?
- Are you experiencing chronic pain resulting from shin splints, stress fractures or other overuse injuries?
- Have you experienced an unhealthy decrease in body fat in relation to your height and weight?
All of the above symptoms can be signs of overtraining. If you've experienced any one of them (or more than one), you may need to scale back your workouts to so that you won't risk any long-term damage to your physical health.
Generally speaking, most people won't fall into the category of performing too much cardio exercise. If you engage in moderate to slightly intense exercise anywhere between 120-150 minutes a week, you're more than likely going to stay within an acceptable range of exercise frequency. However, competitive exercise enthusiasts such as marathon runners, cyclists or triathletes are generally at a higher risk of overtraining due to the intense physical demands of their chosen disciplines.
The keys to maintaining an effective and healthy exercise program are moderation and variety. Keep your cardio to a couple days a week, and don't forget to add in on your off days weight training, lower intensity workouts like yoga or walking, and sports that challenge your body and your mind - play tennis once a week, meet up after work for a basketball game. Living an active life will show you more results over the long run than blasting it out on the treadmill every day.