Children who participate in physical exercise experience greater loss of body fat and increased cardiovascular fitness.[23] Studies have shown that academic stress in youth increases the risk of cardiovascular disease in later years; however, these risks can be greatly decreased with regular physical exercise.[24] There is a dose-response relation between the amount of exercise performed from approximately 700–2000 kcal of energy expenditure per week and all-cause mortality and cardiovascular disease mortality in middle-aged and elderly populations. The greatest potential for reduced mortality is in the sedentary who become moderately active. Studies have shown that since heart disease is the leading cause of death in women, regular exercise in aging women leads to healthier cardiovascular profiles. Most beneficial effects of physical activity on cardiovascular disease mortality can be attained through moderate-intensity activity (40–60% of maximal oxygen uptake, depending on age). Persons who modify their behavior after myocardial infarction to include regular exercise have improved rates of survival. Persons who remain sedentary have the highest risk for all-cause and cardiovascular disease mortality.[25] According to the American Heart Association, exercise reduces the risk of cardiovascular diseases, including heart attack and stroke.[22]
Isokinetic KE MVCs were performed at 60 (panel, A), 100 (panel B) and 140 (panel C) deg/s. Isokinetic KE MVCs were measured pre-exercise (pre, average of all three sessions pre-exercise values), shortly after exhaustion (13 ± 4 s after exhaustion), 20 s following exhaustion test (P20) and 40 s following exhaustion test (P40). Data are presented as mean (SE). * significantly different from pre, $ significantly different from exhaustion and # significantly different from P20, 1 item for P < 0.05 and 3 items for P < 0.001.
* Strength building is an expensive metabolic process. Although we see it as building muscle, our body is making global metabolic adaptations. It is upgrading its metabolic efficiency by synthesizing more enzymes to make metabolism more capable. This includes aerobic metabolism, anaerobic metabolism, gluconeogenesis, glycogen breakdown and transport, blood buffering agents, and of course new muscle fiber growth. All of this new synthesis is extremely metabolically expensive; that is why your body will not make these changes unless an intense stimulus is applied, and the organism is left undisturbed afterwards to make these changes.
This is one way to spend your “rest” day. So instead of lounging on the couch all day you’ll schedule some sort of low-intensity activity like light walking or gentle yoga. The reason why you might want to do this, instead of nothing, is that incorporating gentle movement into these days can help with circulation (which can ease soreness and reduce muscle fatigue). And remember, whether it’s gentle activity or complete rest, your body needs time to recover—when you work out, you’re breaking down muscle fibers, and recovery is when the real magic happens as your muscles rebuild stronger.

Endurance performance (i.e. exercise duration > 1 min) is extensively studied in exercise physiology using cycling and/or running exercise (e.g. [1–4]). Despite being close to real competition events by involving the whole-body, the use of cycling and/or running exercise presents some important limitations to understand the role of the central nervous system (CNS) in the regulation of muscle fatigue and endurance performance. Indeed, as whole-body exercise involves greater systemic responses than isolated exercise [5], it is difficult to interpret some specific experimental manipulations aiming to understand CNS processes regulating muscle fatigue and endurance performance (e.g. manipulation of III-IV muscle afferents [6, 7]). Furthermore, due to the need to transfer the participant from the treadmill/bicycle to the ergometer, the true extent of muscle fatigue at exhaustion is underestimated [8], leading to inconclusive results on how peripheral (i.e. fatigue produced by changes at or distal to the neuromuscular junction [9]) and central (i.e. decrease in maximal voluntary activation level [9]) components of muscle fatigue might interact between each other’s (for review see [2, 9]). Therefore, due to the aforementioned limitations, the development of a new exercise model is required to better investigate the CNS processes regulating endurance performance.
* After you reach your peak of development, you lose muscle tissue every day up until your death. The rate at which you lose muscle tissue significantly affects how fast you "age". Strength building exercise will slow this natural loss of muscle tissue. Would you rather age quickly or slowly? What kind of shape would you prefer to be in when you're in the Fall and Winter of your life?
The aim of this study was to assess the effects of vigorous exercise on functional abilities by means of a Senior Fitness Test (SFT) in a group of elderly adults. Twenty healthy and inactive people performed vigorous exercise (VE: 12 men and 8 women, aged 69.6 ± 3.9 years). At the beginning of the study (T0) and after 3 months (T1), each subject's functional ability was tested for muscular strength, agility, cardiovascular fitness, flexibility, and balance. The VE was designed with continuous and interval exercise involving large muscle activities. Functional exercises were performed between 60% and 84% of heart rate reserve (HRR) for a duration of 65 minutes. Five out of the 6 SFTs performed were found significantly improved: Chair Stand (T0 12.4 ± 2.4, T1 13.5 ± 2.6, p < 0.01), Arm Curl (T0 14.2 ± 3.6, T1 16.6 ± 3.6, p < 0.01), 2 min step (T0 98.2 ± 15.7, T1 108.9 ± 16.2, p < 0.01), Chair Sit-and-Reach (T0 −9.9 ± 7.7 cm, T1 1.7 ± 6.3 cm, p < 0.01), and Back Scratch (T0 −15.8 ± 10.9 cm, T1 −8.4 ± 13.1 cm, p < 0.01). Our results suggest that a high intensity protocol and functional exercises can improve functional mobility and muscle endurance in those over 65 years of age. SFTs are an effective method for assessing improvements in the functional capacity of elderly adults.