After 5 min warm up at 20% of peak power output, subjects performed a time to exhaustion at 85% of peak power output. Exhaustion was defined as a decrease in cadence below 40 cpm for a duration ≥ 10 s or when the subject voluntarily stopped. Subjects were not aware of the time elapsed during the time to exhaustion test. Verbal encouragements were provided by an experimenter naïve of time to exhaustion during the previous sessions.

The baseline characteristics of the study participants are presented in Table 1. No differences between the training groups existed at study entry. In both groups, men spent more hours in sedentary behavior and had significantly higher weight, height, and VO2peak compared to women. Contrary, more women than men performed at least 30 min of daily physical activity (Table 1). The included participants had higher VO2peak (11%) compared to those with no exercise logs. They also had higher VO2peak (17%) and height (1.7%) compared to dropouts, but a lower BMI (3.7%) (p < 0.05). A higher proportion of the included participants performed 30 min of daily physical activity compared to the dropouts (77.3% vs. 66.1%, p < 0.05).
Evidence from HIIT studies conducted under controlled laboratory conditions has provided proof-of-concept of efficacy [9]. However, it has been argued that HIIT has high efficacy but low effectiveness [16], and long-term exercise interventions carried out under free-living conditions have been asked for to investigate whether HIIT is feasible as a public health initiative among older adults [9, 16]. Our data showed that both training groups reported on average more than two exercise sessions per week throughout the year. Approximately 60% of the sessions in the HIIT group were performed with a self-reported high-intensity (≥15 Borg scale), indicating that older adults are able to perform HIIT over a long time-period without strict supervision. However, women had a lower proportion of sessions with high-intensity exercise compared to men. This result is in line with previous findings that women (aged 60–67 years) are less likely than men to prefer vigorous physical activity [23].

Although there is research concluding the effectiveness of the Alfredson protocol, some individuals find the completion of 180 repetitions of exercise daily to be difficult to achieve.  A study in the February 2014 issue of the Journal of Orthopaedic and Sports Physical Therapy indicated that a modified version of the Alfredson protocol with a "do as much as tolerated" approach achieved similar positive results as the full 180 repetition protocol.

Alert: Companies strictly follow their exercise rules and deadlines, and courts tend to side with them. See, for example, Deal v. Consumer Programs, Inc. (2006), decided by the 8th Circuit Court of Appeals. The court ruled that the mere submission of a written notice to exercise stock options may be insufficient when the grant agreement states that the notice must be "accompanied by full payment of the purchase price of the shares."
Rake those leaves. Raking is already an excellent calorie-burning activity, so do it! Raking is not only great for your yard and lawn, but also for your body. Because your core (your back and abdomen) has to work to stabilize your body while your arms are maneuvering the rake, raking is good exercise for both your arms and core. Weirdly, there's a page all about raking as a workout, which you can read here.
KE MVCs were performed at 60, 100 and 140 deg/s. Testing was performed 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). As pre-exercise values for the EMG RMS RF at 60 deg/s differ between sessions (P = 0.038), its time course was not analyzed. Planned comparisons failed to demonstrate significant difference between means for EMG RMS RF at 140 deg/s. VL, Vastus Lateralis muscle; RF, Rectus Femoris muscle; VM, Vastus Medialis muscle, KE, knee extensor muscles (sum VL, RF and VM). Data are presented as mean (SD).
Recruiting lasted 6 months starting from September 2013. Participants were recruited by means of family doctors to whom the goal of the study was explained. The recruitment flow chart is shown in Figure 1. Three hundred and fifty people aged ≥ 65 were invited to participate. Of these, 51.4% agreed to be included in the screening list while 48.6% refused to participate, mainly for family reasons such as illness/hospitalization/old age of a family member. Forty people were found eligible to participate in the research protocol. Randomly, twenty were assigned to VE and twenty to the control group. The latter were instructed not to take part in any physical activity throughout the study period. All the selected participants signed an informed consent. The study was performed according to the Declaration of Helsinki and approved by the local ethics committee on September 23, 2013.