In line with the previous literature, our study showed that walking was the most common exercise type among older adults [24, 25]. This result is not surprising as walking is among the most cost effective and accessible means of exercise [26]. In addition, walking has been identified as a relatively safe exercise alternative to older adults [25]. We found that walking was the most common exercise type in both training groups. However, the MCT group had a higher proportion of walking sessions than the HIIT group, while the HIIT group had a higher proportion of sessions with for instance jogging and cycling. This might indicate that some older adults in the HIIT group feel that it is easier to achieve a high-intensity level when performing jogging and cycling compared to walking. Absolute workload at a given intensity varies greatly among individuals with different levels of cardiorespiratory fitness (CRF) [27], so that e.g. walking at 5 km/h corresponds to moderate intensity for an individual with relatively high CRF level, while the same speed exhibits near-maximal intensity for an individual with low CRF. Therefore, the type of exercise an individual need to perform in order to achieve a feeling of high intensity varies from one individual to another [27]. Since ageing often results in CRF decline [28], it is likely that many older adults will reach a feeling of high-intensity when walking. However, those with a high CRF level might need to perform other exercise types, for instance jogging and cycling, to reach the same intensity level during their workout session.
In total, 1567 participants (790 women) met the inclusion criteria, fulfilled baseline testing and were randomized 1:1 into an exercise training group or to a control group. The exercise training group was further randomized 1:1 to either MCT or HIIT. Participants in the exercise groups were instructed to fill in exercise logs after each exercise session they performed. Data in the present study is based on the exercise logs from the first year of the intervention. Therefore, only participants in the exercise groups were included in the present study (n = 787). Dropouts in the exercise groups during the first year (n = 123) and those with no exercise logs (n = 46) were excluded. A total of 618 participants (291 women) were included in the analyses (Fig. 1). The study was approved by the Regional Committee for Medical Research Ethics (REK sør-øst B: 2015/945) and all participants gave their written informed consent before participation.

Neuromuscular function tests were performed pre and post-exercise to quantify muscle fatigue. As previous studies documented the extent of isometric muscle fatigue induced by OLDE [8, 11, 17, 18], we chose to focus only on isokinetic muscle fatigue. Therefore, knee extensors (KE) MVCs were performed at 60 (MVC60), 100 (MVC100) and 140 (MVC140) deg/s pre (after the warm-up) and post-exercise (13 ± 4s after exhaustion). Subjects were asked to perform two maximal isokinetic knee extensions at each angular velocity (starting position corresponded to knee angle at 90 deg; range of motion was the same as the OLDE). The highest peak torque value of the two trials was considered, and a 20 s recovery was set between each set of KE MVCs. The order of contractions was randomized between sessions as follow (60-100-140 deg/s, 100-140-60 deg/s or 140-60-100 deg/s) and identical for testing pre and post-exercise of the same session. This randomization allows obtaining a time course of KE MVC torque recovery following the time to exhaustion test at each angular velocity was obtained at a different time point at each session: either shortly after exhaustion (13 ± 4 s after exhaustion), 20 s following exhaustion test (P20) and 40 s following exhaustion test (P40). An overview of timing can be found in Fig 1. Twenty seconds after completion of the last KE MVC, a maximal isometric MVC of the knee flexors was performed (isometric KF MVC). Visual feedback of the torque and strong verbal encouragement were provided for each MVC [please see reference 9 for more details].

I've been strength training for over 15 years now. In college, between martial arts and four months of lifting weights for 6 hours per week I gave myself overuse injuries in my shoulders and knee. I've tried everything, including Mike Mentzer's books, Arnold Schwarzennegger's Bodybuilding Bible, Stuart McRobert's Beyond Brawn, Sisco and Little's Power Factor Training, routines from Men's Health, Flex, and Muscle & Fitness magazines - you name it. Super Slow (and its cousins Slow Burn and Power of 10) are the ONLY form of exercise I can handle for more than two months without having those pains flare up with a vengeance and force me to quit. I've done Super Slow for years without the slightest ache except for normal muscle soreness.
Studies show that with fibromyalgia, the initial rise in oxidative stress will begin to decrease as you continue your workout; however, with CFS, prolonged exercise can increase the oxidative stress and the associated pain. This is where you might feel malaise after exercise as well. You can see why it is necessary to start slow and work up with consistency. Having severe M.E. myself, I know it can be done and it does take persistence. 
The simplest way to workout at home is to use your own body. There are a variety of effective body weight exercises that can help you build strength, endurance and burn calories. The downside is that, without added resistance, it's tough to work hard enough to really challenge your body and burn calories. One way around that problem? Circuit training. By going from one exercise to the next, without little or no rest, you keep your heart rate up, burn more calories and get the most out of your exercise time.
If you’re sick of doing endless repetitions of traditional squats, check out this video to challenge your muscles in new ways and spark some creativity. “We asked certified personal trainer and Women’s Health’s Next Fitness Star, Selena Watkins, to pull together 15 dance-inspired versions of this classic booty toner, and the results are giving us a whole new appreciation for an old-school move,” says the magazine. This routine is just a sampler of some of the squat variations you could complete. Pick three or four and incorporate them into your next leg day to spice things up.
Jump up ^ Magnoni, L. J; Crespo, D; Ibarz, A; Blasco, J; Fernández-Borràs, J; Planas, J. V (2013). "Effects of sustained swimming on the red and white muscle transcriptome of rainbow trout (Oncorhynchus mykiss) fed a carbohydrate-rich diet". Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 166 (3): 510–21. doi:10.1016/j.cbpa.2013.08.005. PMID 23968867.
Most gyms assault their members with a cacophony of distractions – thumping music, blaring televisions, and grunting patrons. We are careful to maintain a clean and distraction-free facility. There is no music and there are no mirrors or televisions. The temperature is kept at 68 degrees. The sessions are one-on-one with a focus on privacy. Instructors are dressed professionally at all times and closely monitor and record every aspect of their client's performance.
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.