Most people love to try new things. Being adventurous about trying new fitness trends is a great way to prevent boredom and overcome certain performance plateaus. But it can be risky. The fitness community is not well-regulated and, in some instances, individuals lacking knowledge of physiology have created fitness options that are not effective and possibly unsafe.

Let's look at a few of the most popular fitness trends and sort myth from fact.

Guidelines for flexibility have changed drastically within the last few years. Static stretching before starting exercise is no longer recommended for the general exerciser. According to the American College of Sports Medicine, your best bet is to stretch either after exercise or independent of it.

What about warm-ups? Any active person should do at least five minutes of cardiovascular exercise of low-to-moderate intensity to reduce the risk of injury. If you are already suffering from an injury, your therapist may give you specific stretches to perform prior to, after or separate from exercise.

If you're interested in higher-level flexibility, consider yoga. Most forms of yoga are safe and effective if done properly. Be aware, though, that certain classes pose more risks than others.

Ashtanga or “power yoga” classes can involve abrupt dynamic movements that are not suitable for anyone with a low level of flexibility. Lower-level yoga classes are more appropriate for those individuals.

Also popular are Bikram yoga or “hot yoga” classes, which are performed in a room where the temperature is 90 degrees or higher. These classes can be dangerous for people with heart conditions, high blood pressure, diabetes, and other chronic health limitations, particularly during the colder months. Before signing up for these classes, consult your physician.

Resistance exercise has undergone a revolution as well. Functional strength training is replacing the tried-and-true methods of weight training. Incorporating balance, agility, or exercises that challenge coordination into strength training routines may allow the body to respond better both in daily living and in sport-specific situations.

Examples of trends in strength training include the stability ball, the half-ball (such as the BOSU©), kettle bells, and even high-frequency-vibration equipment.

If you're not interested in purchasing strength equipment, try performing bicep curls, lateral raises, and upright rows while standing on one foot. This technique often can provide similar benefits.

The most common trend in cardiovascular exercise involves monitoring the heart rate and focusing on training intensity. The reliability of heart-rate monitors on exercise equipment is questionable, so using an actual heart-rate monitor that straps around the chest and includes a watch to provide feedback can be helpful. This equipment ranges from the very basic, which displays only the heart rate itself, to the extremely complex, which incorporates a global positioning system. What you choose depends on your needs and performance level.

Not since the aerobics craze in the '80s have exercise classes been so popular. Spinning classes, pool classes, "cardio boot camp," "piloga" (a combination of Pilates and yoga) classes, and ballroom dancing classes are just a few examples.

Be cautious about the suggested benefit of a class. In most cases, you are likely to gain some benefit, but it may not be the benefit you are looking for. For example, if a class claims to offer aerobic exercise but is largely based on strength, the likelihood that it will improve aerobic fitness is slim.

Contact an exercise physiologist or a health or fitness professional if you have questions about the benefits of a particular fitness class.

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