Response Variability and Detraining Effects of Standardized Exercise Programs

Research Article

Austin Sports Med. 2021; 6(1): 1048.

Response Variability and Detraining Effects of Standardized Exercise Programs

Martín–Guillaumes J1, Montull L2*, Ventura JL3, Javierre C3, Aragonés D4 and Balagué N2

1Federación Española de Deportes de Montaña y Escalada (FEDME), Barcelona, Spain

2Complex Systems in Sport Research Group, Institut Nacional d’Educació Física de Catalunya (INEFC), Universitat de Barcelona (UB), Barcelona, Spain

3Department of Physiological Sciences, Medical School, University of Barcelona, Barcelona, Spain

4Institute of Sports Science, Johannes Gutenberg–University Mainz, Mainz, Germany

*Corresponding author: Montull L, Institut Nacional d’Educació Física de Catalunya (INEFC), Universitat de Barcelona (UB), 12 Avinguda de l’Estadi, 08038 Barcelona, Spain

Received: May 10, 2021; Accepted: June 14, 2021; Published: June 21, 2021


Purpose: To compare inter–individual response variability and detraining effects on markers attributed to aerobic and anaerobic performance after shortterm standardized aerobic, strength and mixed training programs.

Methods: Thirty–six male students were randomly assigned to either an aerobic, strength, mixed, or control program (9 per group). They performed two consecutive cycling tests (incremental and plateau) to exhaustion at three points: 1 week before training, after 6 weeks of training, and 3 weeks after the training was finished. Maximal oxygen consumption (VO2max), maximal workload (Wmax), and time to exhaustion performed at Wmax (W × time) were compared between groups by repeated–measures ANOVA with Bonferroni post–hoc tests. The inter–subject response variability within each training group was evaluated by comparison with the 95% confidence interval of the control group. Detraining effects were evaluated using the hysteresis areas, which were compared between each training group and the control group by Mann–Whitney U test.

Results: Differences were observed in Wmax for the aerobic (F(2,7)=19.562; p=0.001; n²=0.85) and mixed (F(2,7)=13.447; p=0.004; n²=0.99) programs, and in W × time for the mixed program (F(2,7)=15.432; p= 0.016; n²=0.89). There was high inter–subject response variability for all variables and training programs, except for a homogenous positive response to Wmax in the mixed program (X²=6.27; p=0.04). Detraining effects of Wmax were also better maintained after the mixed program.

Conclusion: A mixed program of aerobic and strength training demonstrated higher improvements in the studied markers of performance, with lower interindividual response variability, and longer detraining effects compared with aerobic or strength programs.

Keywords: Mixed training; Personal constraints; Aerobic and anaerobic markers; Hysteresis


AER: Aerobic Training; CI: Confidence Interval; CON: Control Group; HIIT: High–Intensity Interval Training; MIX: Mixed Training; STR: Strength Training; VO2max: Maximal Oxygen Consumption; Wmax: Maximal Power; W × time: Wmax Tolerated Per Time.


The benefits of physical activity are well recognized, leading to standardized exercise programs being increasingly prescribed to improve health and performance [1]. Their adequate selection claims for empirical evidence and a good understanding of their individual effects, including those at different timescales. However, the effects of Aerobic (AER), Strength (STR), and Mixed (MIX) training programs have only been studied based on their group mean improvements on performance and physiological variables [2], with no meaningful comparison of their inter–individual variability in training response and detraining effects.

Although some individuals show great improvements in performance and physiological markers after short–term exercise programs, others experience little or no change [3]. In addition, a low training response in one performance or physiological marker does not necessary imply a low training response in others [4–7]. This inter–individual response variability has been previously studied for AER and STR training programs. Although sports performance tests can be classified as reduced according to their aerobic or anaerobic metabolic predominance, both systems are present in greater or lesser involvement depending on the characteristics of the tests [8]. Thus, on the one hand, the tests where most of the energy is used to perform the workout comes from aerobic routes, are related to aerobic metabolism. On the other hand, the tests where most of the energy is used to perform the workout comes from anaerobic routes, are related to anaerobic metabolism. Early research using maximal oxygen consumption (VO2max), one of the common and reliable physiological markers of cardiorespiratory performance, indicated variations from almost no gain [3] to a 100% increase in large groups of sedentary individuals after standardized AER training programs [9–11]. STR programs have also been shown to induce interindividual differences [12], particularly in muscle response [13–15]. However, to our knowledge, inter–individual variability of training responses to MIX programs have not been assessed. The importance of this knowledge gap is emphasized by the fact that MIX programs are commonly followed by elite athletes and are widely recommended in a variety of populations, including prepubescent children [16], adults [17], older adults [18], or cardiac rehabilitation patients [19]. Beyond greater adherence, exercise variability has been associated with higher physiological [20] and cognitive adaptations [21], such as motor patterns retention [22].

Three abilities have been identified that explain inter–individual variability in response to exercise: the ability to perform with minimal training, the speed of adaptation or trainability, and the upper achievable limit [23]. These factors have not been causally related to DNA sequence variations, leading Bouchard and Rankinen [10] to observe that pre–training phenotype and contextual aspects may contribute to variability in training response. For instance, age, sex, race, and anthropometric measures can create differences in AER performance [24,25]. Other authors highlight the potential role of psychosocial variables on performance [26]. Given that redundant and degenerate mechanisms operating at the physiological level limit the general utility of reductionist assumptions like genetic ‘causation,’ complex approaches have been proposed to explain the inter–individual differences in response to training programs [27].

A prominent feature of short–duration standardized programs seems to be the individual rate of adaptation. As Hristovski et al. [28] observed, there is no one–to–one mapping between training dose and effect because training residuals or memory effects play significant roles in neurobiological systems. Figure 1A shows that the relationship between training workload and performance follows a different path during training and detraining phases, the latter being characterized by a less steep trend, whereas Figure 1B shows that the overreaching to the overtraining bifurcation is produced by a small change to the training history.