History and perspectives on interval training in sport, health, and disease

Exercise can be conducted as low-intensity continuous training (LICT) or a variety of higher intensity work/rest formats, collectively called interval training. Interval training was developed for athletes in the early 20th century. It was systemized in Sweden as Fartlek, and in Germany as die interval Method, in the 1930s. Most contemporary forms of interval training evolved from these progenitors. In essence, interval training allows a large volume of high-intensity or race specific training to be performed while controlling the development of fatigue. Adding interval training to LICT done by athletes adds about 2%-4% to performance achievable with LICT, which represents a competitively meaningful difference in performance (e.g., 4:25 vs. 4:00 over 1 mile). More recently, interval training has been applied to health- fitness participants and even to patients with health conditions. Studies indicate that a comparatively low volume of interval training can produce substantial improvement in physiologic capacity, in as little as 20% of training time versus LICT. There are data indicating that interval training can be reasonably pleasant, have good adherence, and is safe, even in patients. Although interval training was originally designed for athletics, the fundamental patterns of work versus recovery are remarkably similar in healthy adults and patients. Although the total volume of training and both absolute and relative intensity and magnitude of homeostatic disturbance are larger in athletes, the overall pattern of effort is the same in fitness participants and patients. Interval training can thus be characterized as an important step in the evolution of exercise training.

Functional Translation of Exercise Responses from Exercise Testing to Exercise Training: The Test of a Model

Exercise prescription based on exercise test results is complicated by the need to downregulate the absolute training intensity to account for cardiovascular drift in order to achieve a desired internal training load. We tested a recently developed generalized model to perform this downregulation using metabolic equivalents (METs) during exercise testing and training. A total of 20 healthy volunteers performed an exercise test to define the METs at 60, 70, and 80% of the heart rate (HR) reserve and then performed randomly ordered 30 min training bouts at absolute intensities predicted by the model to achieve these levels of training intensity. The training HR at 60 and 70% HR reserve, but not 80%, was significantly less than predicted from the exercise test, although the differences were small. None of the ratings of perceived exertion (RPE) values during training were significantly different than predicted. There was a strong overall correlation between predicted and observed HR (r = 0.88) and RPE (r = 0.52), with 92% of HR values within ±10 bpm and 74% of RPE values within ±1 au. We conclude that the generalized functional translation model is generally adequate to allow the generation of early absolute training loads that lead to desired internal training loads.

Exercise Evaluation and Prescription

Ever since the farm boy, Milo of Crotone, lifted a growing bullock every day, to become the strongest man in the world, and six-time champion of the ancient Olympic Games, we have known about the principle of progression of exercise training [...].

Generalized Approach to Translating Exercise Tests and Prescribing Exercise

Although there is evidence supporting the benefit of regular exercise, and recommendations about exercise and physical activity, the process of individually prescribing exercise following exercise testing is more difficult. Guidelines like % heart rate (HR) reserve (HRR) require an anchoring maximal test and do not always provide a homogenous training experience. When prescribing HR on the basis of % HRR, rating of perceived exertion or Talk Test, cardiovascular/perceptual drift during sustained exercise makes prescription of the actual workload difficult. To overcome this issue, we have demonstrated a strategy for "translating" exercise test responses to steady state exercise training on the basis of % HRR or the Talk Test that appeared adequate for individuals ranging from cardiac patients to athletes. However, these methods depended on the nature of the exercise test details. In this viewpoint, we combine these data with workload expressed as Metabolic Equivalent Task (METs). We demonstrate that there is a regular stepdown between the METs during training to achieve the same degree of homeostatic disturbance during testing. The relationship was linear, was highly-correlated (r = 0.89), and averaged 71.8% (Training METs/Test METs). We conclude that it appears possible to generate a generalized approach to correctly translate exercise test responses to exercise training.

A multi-modal exercise intervention that improves cognitive function and physical performance, elderly with mobility-related disability: a randomized controlled trial

BACKGROUND

Physical exercise interventions have showed improvement on cognitive performance and mobility of old people. However, the results regarding the inclusion of cognitive activities into exercise were not evaluated simultaneously. Therefore, the aim of this study was to investigate the effect of multimodal exercise program on cognitive function and physical performance in elderly people with mobility disabilities.

METHODS

The sample of the study consisted of 70 old people randomly appointed to the exercise and control groups (35 people for each) with mobility disabilities. A new exercise program was conducted for old people in the exercise group for 6 months. Evaluation between 1st and 24th week included cognitive change, mobility, balance and walking parameters.

RESULTS

Exercise group showed better performance on orientation, memory and language point than before the intervention (P<0.05). Again, the total mental test score of the exercise group significantly increased from 18.7±3.5 to 20.1±3.5 after the intervention (P<0.001). People without a cognitive disorder increased from 8 to 11 in the exercise group (P<0.001), while the number did not change in control group. Correlation was found between exercise group and activities such as mobility, walking and balance performance (r=0.81; P<0.001).

CONCLUSIONS

A multimodal exercise program with intense mental activities enabled an improvement in both cognitive and physical performance in old people with loss of competences due to mobility.

Graded Exercise Testing Versus Simulated Competition Exercise in Trained Older Males

PURPOSE

Exercise-based rehabilitation is a standard therapy for patients with heart disease. Despite examples of patients who have extended normal rehabilitation exercise into competitive participation, there are no clear-cut guidelines for patients whether they should participate in competitive-level exercise. This study investigated the occurrence of complications, physiologic responses, and exercise patterns during simulated competitive exercise in active, older nonathletes (most with a history of cardiovascular disease) and compared these with responses during maximal incremental exercise.

METHODS

Fourteen trained older males, 7 with stable cardiovascular disease, performed an incremental exercise test and time trial of 55 kJ (equivalent to running ∼1 mile) on a semirecumbent stepping ergometer. Variables of gas exchange, hemodynamics, perception, and power output were measured in both tests.

RESULTS

Subjects attained a remarkably high physiologic and psychologic strain (respiratory exchange ratio >1.0; average peak rating of perceived exertion >8) in both tests, with no evidence of symptomatic, hemodynamic, or electrocardiographic abnormalities. Peak physiologic responses were not significantly different between simulated competition and incremental exercise. The fixed-work time trial was finished in 8.97 ± 1.85 minutes, mean power output of 100 ± 26 W. Results showed a distinct pacing pattern in the relative power output, consisting of a conservative start, an even-paced middle portion, and an end spurt.

CONCLUSIONS

Results suggest that in trained individuals with normal incremental exercise test results, competitive-level efforts may be undertaken with no apparent side effects. This may provide a strategy whereby physicians can advise patients concerning their decision to perform in competitive events.

Exercise for Primary Care

This review discusses physical activity counseling in primary care, including evidence-based perspectives on optimizing the risk-benefit ratio for the majority of patients who are not physically fit.