It is well established that daily physical activity has significant health benefits, both in prevention and in the treatment of many chronic diseases. However, in certain situations, the specific choice of an exercise modality can be crucial to induce specific beneficial adaptations.
When we engage in physical activity, our body undergoes temporary stress that triggers an adaptive response. The repetition of these stresses is responsible for the beneficial adaptations associated with regular exercise. Thus, it is essential to understand which structures will be solicited and will undergo stress depending on the type and intensity of the chosen exercise, in order to induce the desired adaptations.
The Exercise Modality
The choice of exercise modality should be based on the desired objectives as well as acute physiological changes, to ensure they are in line with the individual’s capabilities. Traditionally, exercises are divided into two main modalities: endurance exercise and resistance exercise.
Endurance exercises are long-duration, moderate-intensity activities that heavily involve the muscular energy systems as well as the cardiovascular system during the exercise. In contrast, resistance exercise involves the skeletal muscles and the nervous system, and is therefore often associated with activities requiring external weights, such as weightlifting.
However, it would be reductive to say that all exercises belong exclusively to one of these categories because the majority of practiced exercises can often be a mix of both modalities. For example, a HIIT (High Intensity Interval Training) type exercise performed in a gym may consist of a sequence of weightlifting exercises at high cardiovascular intensity interspersed with rest periods.
Endurance Exercises
Endurance exercises are often performed at an intensity between 55 and 75% of the maximum heart rate, which allows for the recruitment of aerobic muscular energy systems that produce energy via the mitochondria from carbohydrates/lipids.
More specifically, skeletal muscle will produce more energy from carbohydrates, derived from muscular glycogen, and lipids, derived from adipose tissue, using oxygen from the ambient air. At low intensity, lipids are primarily used and as the intensity increases, carbohydrates will be used more. For skeletal muscle to produce this energy, a high intake of lipids and oxygen is required, which will be ensured by an increase in heart rate and an increase in the diameter of blood vessels, allowing for an increased amount of blood flowing within the muscles.
Therefore, endurance exercises are particularly beneficial for:
- Improving cardiovascular and metabolic health
- Loss of fat mass during an appropriate nutritional management
- An increase in endurance capacity
The simplest way to place oneself at the right intensity is to use a heart rate monitor and calculate one’s maximum heart rate by the formula Fcmax = 220 – age. However, not everyone has a heart rate monitor, and it is possible to rely on the talk test, meaning we are able to hold a conversation but need to catch our breath sporadically.
HIIT Exercises
HIIT exercises consist of alternating high-intensity exercise periods, about 85-95% of maximum heart rate, with rest periods or low-intensity exercise. In common language, they are often referred to as interval exercises that stimulate both the skeletal muscle and the cardiovascular system at higher intensities than during endurance exercise but over shorter periods. However, this type of exercise allows for similar adaptations in the cardiovascular system and metabolism as endurance exercise.
In addition to more specific endurance adaptations, HIIT exercises can induce a gain in muscle mass similar to low-intensity weight training exercises.
Thus, this type of exercise can be recommended to improve performance in individuals with limited time available for sports practice, as well as to improve capacity and cardiovascular health in individuals engaging in weight training who want to maintain their muscle mass. Finally, it can also be recommended to promote fat loss in people with limited time or who do not enjoy endurance exercises.
In general, HIIT exercise modalities are:
| Repetitions | Exercise (duration, intensity) | Rest | |
| REHIT | 2-3 | 20 sec, sprint maximum | 2-3 min |
| Tabata | 7-8 | 20 sec, sprint maximum | 10 sec |
| Wingate | 4-10 | 30 sec, sprint maximum | 4 min |
| Gibala | 10 | 60 sec, greater than 90% of maximum HR | 60 sec |
| Norvégien | 4 | 4 min, 85-95% of maximum HR | 3 min |
These modalities are diverse and can therefore be adapted to the individual and their capacities to avoid inducing excessive fatigue.
Exercices RET
Resistance exercises include weightlifting with external weights or body weight, and thus, they are beneficial for both the musculoskeletal system and the nervous system.
During this type of exercise, moving a load causes an increase in the tension applied to the muscle, which stimulates muscle protein synthesis (and thus hypertrophy). Consequently, this type of exercise should also be accompanied by an appropriate protein intake, the doses of which are described in this article (https://aminogram.com/apport-proteique-dans-la-pratique-sportive/). Moreover, performing these movements is also accompanied by a significant exchange of nerve signals between the skeletal muscles and the central nervous system, which can alter its functioning. This notably allows for improved proprioception, that is, the ability to sense one’s body in space, and therefore balance, the ability to move, etc.
Considering its benefits, this type of exercise can be recommended for:
- Individuals with chronic diseases aiming to increase or maintain their skeletal muscle mass and therefore their functional capacity.
- Sedentary individuals or those practicing recreational sports activities aiming to increase their skeletal muscle mass for health and/or aesthetic purposes.
- Athletic individuals looking to improve their muscle mass and/or enhance a specific sports quality related to their sport, such as movement speed or maximum strength.
Depending on the individuals’ goals, several resistance exercise modalities exist and they are organized into blocks of repeated movements, interspersed with rest periods. Traditionally, weight training exercises are divided in this way:
- For strength gain, between 3 and 5 sets of 4-5 repetitions close to the maximum (80-90%) interspersed with 1 min 30 sec-2 min of rest.
- For muscle hypertrophy, between 3 and 5 sets of 10-12 repetitions between 70 and 80% of the maximum, depending on the training level, interspersed with 1 min-1 min 30 sec of rest. It is also possible to perform this type of exercise with lower weights in the case of individuals having difficulties lifting heavy loads.
Conclusion
As described in this document, the different exercise modalities involve precise physiological structures and result in specific beneficial adaptations to each of them. It is therefore important to know the characteristics of these modalities in order to advise individuals in the most appropriate way based on the beneficial adaptations sought, as well as the goals and physical capabilities of each individual.
