The main aim of this study was to test the reliability of a novel OLDE protocol performed at high intensity (workload fixed at 85% peak power output [22]). Isokinetic muscle fatigue and its recovery up to 40 s post exercise were also measured. Subjects visited the laboratory on four different days. During the first visit, subjects were familiarized with the OLDE protocol (see One Leg Dynamic Exercise for more details), and performed after 30 min recovery an incremental test to measure peak power output. After 30 min recovery following the incremental test, subjects were familiarized with neuromuscular testing (see Neuromuscular Function Tests for more details) and the time to exhaustion test. As suggested by Andersen et al. [10], torque and electromyographic (EMG) feedback were used to ensure a quick and reliable familiarization to the novel OLDE protocol. Each of the following three visits (reliability sessions) consisted of completion of the time to exhaustion test with neuromuscular testing pre and post-exercise. An overview of these three sessions can be seen in Fig 1.
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.