The exercising sequence is presented in Figure 2, and training was conducted in three workouts per week. The program was divided into training A and B, so that on Monday and Friday, training A was performed, and, on Wednesday, training B was performed. In the next week, training A was performed on Wednesday, and training B was performed on Monday and Friday. The consecutive weeks followed this same order for the training sessions. For all listed exercises, three series until voluntary concentric failure were performed, and the number of repetitions and rest intervals between series and exercises was followed according to the weekly intensity prescribed, as shown in Figure 1. The average duration for the training sessions was 50 minutes, and, for the repetitions, it was 3-4 seconds, taking into account the concentric and eccentric phases of the movement. All sessions were individually supervised by a strength and conditioning specialist.
The strength training was performed for 12 weeks (Figure 1). The load increase occurred for three consecutive weeks. At the 4th, 8th, and 12th weeks the load was decreased to 12RM, and the participants reduced their training frequency from three to only two weekly sessions (Figure 1). These weeks were planned to provide an optimal recovery of the participants. Another important variable considered was that for both training groups, the intensity and the volume were equated, as recommended by Rhea et al. (26,27). All sessions were individually supervised by experienced strength and conditioning specialists who directly monitored training sessions.
Complementary Aerobic Training
In the 12 weeks of training, two weekly 30-minute aerobic sessions were conducted. These sessions consisted of treadmill running at a speed adjusted according to the target heart rate achieved (THR) of 60%, determined by the equation proposed by Karvonen et al. (18): THR = % (HRmax − HRrest) + HRrest, where % = selected work percentage, HRmax = maximal heart hate, and HRrest = resting heart hate. Heart rate was monitored in all training sessions by a heart rate monitor. The estimated HRmax was calculated from the Tanaka et al. (29) equation: HRmax = 208 − (0.7 × age), specific for healthy adults. It has been previously shown that a complementary aerobic training performed two times per week does not exert negative influence on the muscle strength variables (19,31). Additionally, the participants were instructed to maintain their normal food intake during the research.
All data are presented as mean ± SEM. The statistical analysis was initially done by the Shapiro-Wilk normality test and by the homoscedasticity test (Bartlett criterion). All variables presented normal distribution and homoscedasticity, so the repeated-measures analysis of variance (ANOVA) (two groups at five time points) was used, and when the difference presented was significant, the Tukey post hoc test for multiple comparisons was applied. To determine that there were no differences between the two groups for the variables analyzed, before the training began, Student's t-test was used. In all calculations, a critical level of p ≤ 0.05 was fixed. Test-retest reliability for maximal strength was determined using an intraclass correlation coefficient (ICC) (10). The software package used was Statistica 6.1.
A significant decrease in fat mass (17.76%, p = 0.04) was observed in the evaluation after 12 weeks for LP (A4L) in comparison with the baseline evaluation of LP (A1L). However, in the other evaluations for LP and RLP, no statistically significant differences were observed in fat mass (Table 2).
There was an increase in fat-free mass of 6.62% (p = 0.04) and 7.18% (p = 0.02) for LP in A4L and after 1 week of detraining (A5L), respectively, in relation to A1L (Table 2). On the other hand, no significant alterations were found in fat-free mass for the RLP group during the study (Table 2). Finally, fat-free mass was significantly increased in all evaluations for the LP group (evaluation after 4 weeks of training: A2L→8.91%, p = 0.01; evaluation after 8 weeks of training: A3L→7.32%, p = 0.03; A4L→7.58%, p = 0.03; A5L→8.65%, p = 0.01) in comparison with RLP group.
There was a significant decrease of 16.58% in body fat percentage (p = 0.01) for the LP group in A4L and a decrease of 17.19% (p = 0.01) in A5L compared with baseline (Table 2). In contrast, for the RLP group, no statistically significant differences were observed in body fat percentage between the evaluations or in comparison with LP (Table 2).
The LP group presented significant increases in bench press maximal strength of 10.66% (p = 0.04) in A3L, 14.57% (p = 0.01) in A4L, and 17.38% (p = 0.01) in A5L in comparison with A1L (Figure 3A). Furthermore, in the LP group, increases of 10.68% (p = 0.02) in A4L and 13.62% (p = 0.01) in A5L were found in comparison with A2L for the bench press (Figure 3A). For the RLP group, significant increases in bench press maximal strength were observed in A4LR (16.15%, p = 0.04) and A5LR (16.59%, p = 0.04) in comparison with A1LR. No statistically significant differences were found between the LP and RLP groups in the bench press (Figure 3A).
The LP group presented a significant increase in all evaluations during the training period (A2L, A3L, A4L) and in A5L in comparison with the baseline evaluation. This increase was 12.07% (p = 0.01) in A2L, 21.14% (p = 0.01) in A3L, 26.45% (p = 0.01) in A4L, and 29.5% (p = 0.01) in A5L (Figure 3B). The LP group also showed increases of 10.31% (p = 0.03) in A3L, 16.35% (p = 0.01) in A4L, and 19.82% (p = 0.01) in A5L in comparison with A2L (Figure 3B). Moreover, in A5L there was a significant increase in lat pull-down strength of 10.6% (p = 0.03) in comparison with A3L (Figure 3B).
For the RLP group there were increases in lat pull-down strength in A3LR (16.96%, p = 0.01), A4LR (21.55%, p = 0.01), and A5LR (21.98%, p = 0.01) when compared with A1LR (Figure 3B). Furthermore, for lat pull-down, the RLP group presented an increase of 11.12% (p = 0.01) in A3LR, 16.03% (p = 0.01) in A4LR, and 16.49% (p = 0.01) in A5LR in comparison with A2LR (Figure 3B).
In the comparison between the periodizations, LP was superior to RLP in lat pull-down strength, so significant increases were observed in all evaluations performed during the training and after 1 week of detraining in LP in comparison with the same evaluations in RLP. The increases were 12.65% (p = 0.01) in A2, 11.86% (p = 0.01) in A3, 13% (p = 0.01) in A4, and 16.13% (p = 0.01) in A5 (Figure 3B).
For the LP group, there was a significant increase of 9.96% (p = 0.04) in arm curl strength in A3L, 15.67% (p = 0.01) in A4L, and 20.42% (p = 0.01) in A5L when compared with A1L (Figure 3C). The LP group also presented significant increases of 11.19% (p = 0.01) in A4L and 16.20% (p = 0.01) in A5L in comparison with A2L (Figure 3C). An increase of 11.62% (p = 0.01) in A5L was observed when compared with A3L. For the RLP group, arm curl strength showed increases of 17.07% (p = 0.01) in A4LR and 15.7% (p = 0.03) in A5LR when compared with A1LR. No statistically significant differences were found between the other evaluation periods for the RLP group in the arm curl (Figure 3C). When the periodizations were compared, the LP group showed an increase in arm curl strength of 14.79% (p = 0.01) in A5L in comparison with the RLP group in the same evaluation period (Figure 3C).
There was a significant increase in leg extension maximal strength in all evaluations (A2, A3, A4, and A5) for both periodizations (LP and RLP) in comparison with A1. The evaluations A2L, A3L, A4L, A5L, A2LR, A3LR, A4LR, and A5LR showed increases of 22.30% (p = 0.01), 30.62% (p = 0.01), 36.84% (p = 0.01), 36.84% (p = 0.01), 18.46% (p = 0.04), 25.35% (p = 0.01), 30.26% (p = 0.01), and 31.76% (p = 0.01), respectively (Figure 3D). However, for the LP group, increases of 18.71% (p = 0.01) in A4L and 18.71% (p = 0.01) in A5L were observed in comparison with A2L in the leg extension (Figure 3D).
Local Muscular Endurance
No statistically significant differences were observed in local muscular endurance for arm curl and leg extension in the evaluations performed during the study (A1, A2, A3, A4, A5) for both groups (LP and RLP) (Table 3).
Intraclass Correlation Coefficient
According to the Fleiss (10) classification, maximal strength in bench press, leg extension, and arm curl presented moderate to good reliability for the LP and RLP groups. On the other hand, maximal strength in lat pull-down presented poor reliability for the LP and RLP groups (Table 4).
The aim of the present study was to compare maximal strength gains and alterations in body composition after two different periodizations with loads between 4 and 14RM in trained women. The volume and intensity of LP and RLP were equal and lasted a period of 12 weeks, plus a detraining week. The results show that both LP and RLP induce increases in maximal strength for the upper and lower body. However, LP produced a higher percent increase in strength, for the upper and lower body, in comparison with RLP. Therefore, although the participants of the present study had a minimum of 6 months of experience in strength training, on the basis of these results, the modifications of training loads with the periodizations applied constituted a new stimulus for them.
A variety of studies have shown the benefits of strength training programs in improving strength (21,24,28). Indeed, other authors have conducted studies with LP models (7,19,22), and the results have emphasized that LP was efficient in inducing positive alterations in body composition and maximal strength. Similarly, the present study results show that the group submitted to LP increased fat-free mass in all evaluations and decreased body fat percentage after 12 weeks of training, and that these values remained decreased after 1 week of detraining in comparison with baseline measurements. These alterations were not detected for the RLP group.
The strength gains during the first weeks of training are more dependent on neural adaptations (1-8 weeks); therefore, after this period, more significant alterations may occur in muscle mass and fat mass, assuming that these modifications can be detected earlier, but to a lesser extent (8). This is in agreement with the present study, because more pronounced alterations with regard to body composition occurred after 12 weeks of training. Similarly, other studies found increases in fat-free mass, showing an average increase of 2-4% with strength training and similar periods of analysis to those of the present study (6,19).
Hunter et al. (16) found that after 25 weeks of periodized strength training with variable intensities (50 to 65 to 80% of 1RM in the same week) and 3 days of weekly frequency, there were significant decreases in body fat (kg) and body fat percentage (%) in elderly men and women. Corroborating, Prestes et al. (25) verified that linear strength training periodization associated with aerobic training for 16 weeks promoted reductions in body fat percentage and in abdominal and waist circumference. In contrast, Kraemer et al. (19) did not observe decreases in fat body after 6 months of periodized strength training in young detrained women.
The purpose of the present research in choosing LP was based on several studies that have used this model (3,4,19,26,27), and also because of the great application in practice. On the other hand, only one study by Rhea et al. (27) was found that had directly compared the effects of LP with those of RLP. However, the goal of the loads used by the authors was to increase local muscular endurance. Therefore, to date, this is the first study to compare LP and RLP using higher loads, between 4 and 14RM.
The results of the present study show a significant gain in maximal strength levels for all tested exercises (bench press, lat pull-down, arm curl, and leg extension), with more pronounced increases in LP. In accordance with the present study, several studies have reported gains in maximal strength levels after LP with the objective of muscle hypertrophy (3,15,19).
Among the mechanisms involved in strength increases are motor unit firing rate and increased neural drive, decrease in antagonist muscle coactivation and addition of new myonuclei by activation of satellite cells and myofibers (muscle hypertrophy), and others (1,8,14).
During the initial 4 weeks of training in the present study, there was an increase in maximal strength in lat pull-down and leg extension and after 8 weeks in bench press and arm curl for the LP group, without significant modifications occurring in body composition (which were observed only after 12 weeks of training), emphasizing that the initial adaptations for strength increase were the results of neural factors, predominantly. Interestingly, another important finding was that although RLP began with higher training loads in comparison with LP, manifestations of strength gain were delayed in this group, and no body composition alterations were detected for RLP.
In local muscular endurance, no significant statistical alterations were observed for LP and RLP in arm curl and leg extension. In contrast to the present study, Rhea et al. (27) have proposed a comparison between LP, RLP, and DUP with 15 weeks of training, involving three series varying from 15, 20, and 25RM, organized according to each periodization model. The authors conclude that the gradual increase in volume and decrease in intensity (by RLP) was more effective for increasing local muscular endurance.
However, the present study shows that RLP is not the most effective periodization model for strength gains. Indeed, LP was a more effective method for increasing strength when compared with RLP. Therefore, the higher loads used in this study were possibly not a specific stimulus to increasing local muscular endurance.
Nevertheless, the present study found that LP had more significant results in the variables analyzed (maximal strength and body composition) in comparison with RLP, and these alterations were directly related to intensity applied (4-14RM). In this study, a missing comparison was a DUP group, as Rhea et al. (26,27) have shown superior results in maximal strength for DUP compared with either LP or RLP.
Interestingly, after 1 week of detraining, in which no exercise was performed, there was no decrease in maximal strength and no negative alterations in body composition. In fact, for muscle strength, a percent increase was found during this week; however, there were no statistically significant differences in these values in comparison with the evaluation made after 12 weeks. Other studies have shown that after 8-12 weeks of detraining, muscle strength can decrease significantly, with values between 12 and 68% (13,30).
Gibala et al. (12) found that after 10 days of reduced training, positive effects on strength were observed in trained individuals. In this sense, there are several questions raised by the professionals involved in strength training and conditioning. If an individual stops training, how long does it take for strength to decrease significantly? For how long can a regularly trained individual stop training without decreasing performance and fat-free mass and increasing fat mass? The answers to these questions are complex and depend on a series of factors, such as individual physical fitness, type of strength training, and nutritional and genetic factors.
Yet, at least in a population with similar characteristics to those of the individuals in the present study, a detraining week seems to be efficient for maintaining muscle strength and body composition, after a 12-week period of strength training in LP and RLP models.
Linear periodization strength training with 4-14RM for 12 weeks can induce positive effects on body composition by increasing fat-free mass and decreasing body fat, which was not observed for RLP. However, LP and RLP can induce significant gains in maximal strength for the upper and lower body. On the other hand, as regards local muscular endurance, both in LP and RLP at intensities between 4 and 14RM, no increase was observed. From this aspect, it is clear that the increases in strength manifestations depend on training specificity.
Another important finding of the present research was that after 1 week of detraining, no negative effects were observed in upper- and lower-body strength and body composition. These results have direct implications in strength training and conditioning practice, considering that, for young, trained women, 1 week may be an adequate period for application of detraining without causing a decrease in the performance of the parameters analyzed.
With regard to the model of periodization applied, LP presented more positive effects on body composition and maximal strength in comparison with RLP, when intensity was between 4 and 14RM. There is a possibility for LP to be more effective as it allows for more quality training with the lead up to heavier weights at the end. Other comparisons with DUP, LP, and RLP using different intensities and populations are required.
1. Adams, GR. Exercise effects on muscle insulin signaling and action invited review: autocrine/paracrine IGF-I and skeletal muscle adaptation. J Appl Physiol
93: 1159-1167, 2002.
2. American College of Sports Medicine. Progression models in resistance training for healthy adults. Med Sci Sports Exerc
34: 364-380, 2002.
3. Baker, D, Wilson, G, and Carlyon, R. Periodization
: the effect on strength
of manipulating volume and intensity. J Strength Cond Res
8: 235-242, 1994.
4. Brown, LE. Nonlinear versus linear periodization
models. Strength Cond J
23(1): 42-44, 2001.
5. Brown, LE and Weir, JP. Procedures recommendation I: accurate assessment of muscular strength
and power. J Exerc Physiol
4: 1-21, 2001.
6. Chilibeck, PD, Calder, AW, Sale, DG, and Webber, CE. Twenty weeks of weight training increases lean tissue mass but not bone mineral mass or density in healthy, active young women. Can J Physiol Pharmacol
74: 1180-1185, 1996.
7. Chilibeck, PD, Calder, AW, Sale, DG, and Webber, CE. A comparison of strength
and muscle mass increases during resistance training in young women. Eur J Appl Physiol
77: 170-175, 1998.
8. Deschenes, MR and Kraemer, WJ. Performance and physiologic adaptations to resistance training. Am J Phys Med Rehabil
81: S3-S16, 2002.
9. Fleck, SJ. Periodized strength training
: a critical review. J Strength Cond Res
13: 82-89, 1999.
10. Fleiss, JL. The Design of Clinical Experiments
. New York: John Wiley & Sons, 1986.
11. Fry, AC. The role of resistance exercise intensity on muscle fibre adaptations. Sports Med
34: 663-679, 2004.
12. Gibala, MJ, MacDougall, JD, and Sale, DG. The effects of tapering on strength
performance in trained athletes. Int J Sports Med
15: 492-497, 1994.
13. Graves, JE, Pollock, ML, Leggett, SH, Braith, RW, Carpenter, DM, and Bishop, LE. Effects of reduced training frequency on muscular strength
. Int J Sports Med
9: 316-319, 1988.
14. Häkkinen, K, Alen, M, Kallinen, M, Newton, RU, and Kraemer, WJ. Neuromuscular adaptation during prolonged strength training
, detraining and re-strength
-training in middle-aged and elderly people. Eur J Appl Physiol
83: 51-62, 2000.
15. Herrick, AB, and Stone, WJ. The effects of periodization
versus progressive resistance exercise on upper and lower body strength
in women. J Strength Cond Res
10: 72-76, 1996.
16. Hunter, GR, Wetzstein, CJ, McLafferty, JR, Zuckerman, PA, Landers, KA, and Bamman, MM. High-resistance versus variable-resistance training in older adults. Med Sci Sports Exerc
33: 1759-1764, 2001.
17. Jackson, AS, Pollock, ML, and Ward, A. Generalized equations for predicting body density of women. Med Sci Sports Exerc
12: 175-182, 1980.
18. Karvonen, M, Kentala, K, and Musta, O. The effects of training heart rate: a longitudinal study. Ann Med Exptl Biol Fenn
35: 307-315, 1957.
19. Kraemer, WJ, Nindl, BC, Ratamess, NA, Gotshalk, LA, Volek, JS, Fleck, SJ, Newton, RU, and Häkkinen, K. Changes in muscle hypertrophy in women with periodized resistance training. Med Sci Sports Exerc
36: 697-708, 2004.
20. Kraemer, WJ, Ratamess, N, Fry, AC, Triplett-McBride, T, Koziris, LP, Bauer, JA, Lynch, JM, and Fleck, SJ. Influence of resistance training volume and periodization
on physiological and performance adaptations in collegiate women tennis players. Am J Sports Med
28: 626-633, 2000.
21. Kraemer, WJ, Volek, JS, Clark, KL, Gordon, SE, Incledon, T, Puhl, SM, Triplett-McBride, NT, McBride, JM, Putukian, M, and Sebastianelli, WJ. Physiological adaptations to a weight-loss dietary regimen and exercise programs in women. J Appl Physiol
83: 270-279, 1997.
22. Marx, JO, Ratamess, NA, Nindl, BC, Gotshalk, LA, Volek, JS, Dohi, K, Bush, JA, Gomez, AL, Mazzetti, SA, Fleck, SJ, Häkkinen, K, Newton, RU, and Kraemer, WJ. Low-volume circuit versus high-volume periodized resistance training in women. Med Sci Sports Exerc
33: 635-643, 2001.
23. Matuszak, ME, Fry, AC, Weiss, LW, Ireland, TR, and McKnight, MM. Effect of rest interval length on repeated 1 repetition maximum back squats. J Strength Cond Res
17: 634-637, 2003.
24. Nindl, BC, Harman, EA, Marx, JO, Gotshalk, LA, Frykman, PN, Lammi, E, Palmer, C, and Kraemer, WJ. Regional body composition changes in women after 6 months of periodized physical training. J Appl Physiol
25. Prestes, J, Frollini, AB, Borin, JP, Moura, NA, Júnior, NN, and Perez, SEA. Efeitos de um treinamento de 16 semanas sobre a composição corporal de homens e mulheres. Rev Bras Ativ Fis Saúde
11: 19-28, 2006.
26. Rhea, MR, Ball, SB, Phillips, WT, and Burkett, LN. A comparison of linear and daily undulating periodization
with equated volume and intensity for strength
. J Strength Cond Res
16: 250-255, 2002.
27. Rhea, MR, Phillips, WT, Burkett, LN, Stone, WJ, Ball, SB, Alvar, BA, and Thomas, AB. A comparison of linear and daily undulating periodized programs with equated volume and intensity for local muscular endurance. J Strength Cond Res
17: 82-87, 2003.
28. Ross, R, Janssen, I, Dawson, J, Kungl, AM, Kuk, JJ, Wong, SL, Nguyen-Duy, TB, Lee, S, Kilpatrick, K, and Hudson, R. Exercise-induced reduction in obesity and insulin resistance in women: a randomized controlled trial. Obes Res
12: 789-798, 2004.
29. Tanaka, H, Monahan, KD, and Seals, DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol
1: 153-156, 2001.
30. Thorstensson, A. Observation on strength training
and detraining. Acta Physiol Scand
100: 491-493, 1977.
31. Volpe, SL, Walberg-Rankin, J, Rodman, KW, and Sebolt, DR. The effect of endurance running on training adaptations in women participating in a weight lifting program. J Strength Cond Res
7: 101-107, 1993.
Keywords:© 2009 National Strength and Conditioning Association
periodization; strength training; strength