During your workout you have “target” heart rate zones that are expressed as a percentage of your max heart rate. For low-intensity cardio, you want to aim for 60 to 70 percent of your max heart rate, for moderate-intensity cardio the goal is 70 to 85 percent, and for high-intensity cardio, 85 percent or above. This can help you see if you’re really working as hard as you think you are and adjust as needed to make sure you’re hitting your workout goals. Here’s how to calculate your max and target heart rate zones.

The exercise videos became a series, and Fonda eventually released 23 workout videos. Fonda's exercise videos were such a success because they were the first media of their time to send the message that it was socially acceptable for women to participate in exercise culture and become muscular. Fonda's videos also helped to spark the aerobic exercise trend of the 1980s, not to mention the period's iconic fashion trend: a neon exercise outfit with a leotard and leg warmers. The aerobic exercise craze became so widespread that a Muppets parody tape titled Miss Piggy's Aerobique Exercise Workout Album was released in 1982. The album cover featured Miss Piggy in a Fonda-esque exercise outfit, complete with leg warmers and a leotard, in a pose imitating that which was famously modeled by Jane Fonda on the cover of her first tape.
It is well known that exercise in the older population may prevent several diseases [1–4]. Reduced physical activity impairs the quality of life in elderly people with Alzheimer's Disease [4], Parkinson's Disease [5], and Depressive Disorders [6]. Moreover, musculoskeletal, cardiopulmonary, and cerebrovascular decline are associated with poor physical fitness because of the cumulative effects of illness, multiple drug intake, fatigue, and bed rest [7, 8]. The effects of physical activity and exercise programs on fitness and health-related quality of life (HRQOL) in elderly adults have been widely studied by several authors [9–11]. De Vries et al. [11] conducted a meta-analysis focusing on elderly patients with mobility problems and/or multimorbidity. Eighteen articles describing a wide variety of actions were analyzed. Most used a multicomponent training program focusing on the combination of strength, balance, and endurance training. In 9 of the 18 studies included, interventions were supervised by a physical therapist. Intensity of the intervention was not reported and the duration of the intervention varied from 5 weeks to 18 months. This meta-analysis concluded that, considering quality of life, the exercise versus no-exercise studies found no significant effects. High-intensity exercise appears to be somewhat more effective in improving physical functioning than low-intensity exercise. These positive effects are of great value in the patient population but the most effective type of intervention remains unclear. Brovold et al. [7] recently examined the effects of high-intensity training versus home-based exercise programs using the Norwegian Ullevaal Model [12] on a group of over-65-year-olds after discharge from hospital. These authors based their study on the Swedish Friskis-Svettis model [13] which was designed by Johan Holmsater for patients with coronaropathy to promote their return to work and everyday activities and improve their prognoses. This model includes three intervals of high intensity and two intervals of moderate intensity, each one lasting for 5 to 10 minutes. Included in each is coordination. Exercises consist of simple aerobic dance movements and involve the use of both upper and lower extremities to challenge postural control [13]. Exercise intensity was adjusted using the Borg Rating of Perceived Exertion (RPE) Scale. Moderate intensity was set between 11 and 13, and high intensity was set between 15 and 17 on the Borg Scale.
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