Linear Vs. Daily Undulating Periodisation For Muscle Strength.

Periodisation is used to systematically plan an athletes training throughout the year. Different variables including volume, intensity, exercise choice, rest and frequency. which are organized into different phases of Macrocycle (1 year up to 4 years), mesocycle (monthly blocks) and microcycle (weekly) with the intentions of improving a athletes performance when needed. (Baechle and Earle, 2008). Each phase will have a specific goal depending on whether it is off-season training, pre-season training, in-season training or post-season training. There are different sorts of periodisation model that are around today compared to when Leo Matveyev first published the traditional model in 1964, which have been adopted by coaches to fit their athletes and their particular niche. (Issurin, 2014).

Linear periodisation (LP) and daily undulating periodisation (DUP) is where the focus of this review is, in finding out whether one model is superior over the other in strength gains. The LP model consists of a Preparation, hypertrophy, strength, power and a restorative phase. Each cycle has a particular goal. The DUP model is when the volume and intensity will go up and down over the course of a single week so each work out could be different reps and set ranges each time (Baechle and Earle, 2008). The early 1980’s and 1990’s is when the comparison of different models started to develop for strength training in particular. Stone et al (1982) suggested that their theoretical model due to the concepts and principles would make it superior over other training programmes. In (1983) Stowers et al conducted a study looking at the lower body (squat 1RM), upper body (bench press 1RM) and body weight over an eight week period. Group one had to do one set to exhaustion, group two, three sets to exhaustion and the third group had a periodised program where sets and reps were varied. Results suggested the periodised group had a better overall improvement out of the three groups but nothing significant.

However, all groups had made upper body gains and no significant differences in body-weight occurred either. Due to one of the groups having a periodised program, the expectation of volume data from the study could have been included in the results making it hard to specifically use the study as a reliable source considering volume is one of the main variables in periodisation comparisons. To gain a more rounded knowledge of periodisation volume data would be important to use. In a 16 week study, three groups took part in a program where participants were to train three times a week. Group 1 5x10RM at 78.9% of 1RM. Group 2 6x8RM at 83.3% of 1RM. The repetitions and intensity remained the same for the duration of the 16 weeks and Group 3 changed at 1 - 4 weeks at 5x10RM at 78.9%of 1RM, weeks 5 - 8 at 6x8RM at 83% of 1RM, weeks 9-12 at 3x6RM at 87.6% of 1RM and weeks 13-16 a 3x4RM at 92.4% of 1RM.

All groups matched in volume for the first eight weeks. The last eight weeks were unmatched being 75-90% reduced for the periodised group. The periodised group gained significant relative strength compared to the other two groups (Willoughby, 1993). Baker et al. (1994) conducted a similar study where there were three groups tested in a similar fashion to Willoughby which suggested that periodised groups would improve overall. The participants in the study were untrained males which possibly could have had an effect on the results. For beginners in strength training, it is quite common for an individual to make considerable gains, to begin with, compared to a trained individual (Gomes, 2018). Willoughby highlighted volume played a part in training adaptions, a greater understanding of how volume effects muscle strength adaptions needed further research. Baker et al. (1994) Conducted a study consisting of three groups where all three groups were all matched for volume 1: Non-periodised control (CON), group 2: LP and group 3: DUP. Similar responses in all groups were noted of increased bench press and squat strength. The sample size was limited due to an influenza epidemic. An appropriate sample size gives the research more efficient and reliable data. Use of a sample size calculation influences research findings. Small samples undermine the validity of an article internally and externally. (Faber and Fonseca, 2014) Rhea et al. (2002) Conducted a study on undulating periodisation slightly more intense than that by Baker et al. in 1994. Adjusting the intensity and the volume of the training each day, this would make the training more intense. Rhea et al. (2002) suggested Baker et al. (1994) did not get any significant results due to low intensity. Previous comparisons of DUP and LP have not been able to answer questions on the topic because during testing because groups were not matched for volume and intensity. A twelve-week study with two groups which both had to take part in three sets of leg press and bench press. Volumes and intensities were both matched. Strength increases compared. Both LP and UP increased strength significantly (p, 0.05) in both leg and bench press over the duration of the program. The DUP group increased x2 (24% vs. 14%) bench press, similarly in leg press (55% vs. 25%) compared to the LP group.

The strength of the participants was considerably different which could be a limitation to the results due to trained individuals may have limited progress than those untrained. Prestes et al. (2009) Conducted a study Comparing strength gains of LP and DUP weight training programs of 12 weeks in duration. Volume and intensity were matched. LP showed an increase of 15.16 kg (p = 0.041). DUP showed a higher percentage increase of 22.4 kg. No significant differences reported between LP and DUP groups in the bench press. Leg press 45kg maximal strength; the LP group showed a significant increase of 65.5 kg. DUP group had a higher percentage increase of 40.61%, DUP group showed a significant increase of 12.23% (28 kg) arm curl of maximal strength, LP group demonstrated a significant increase of 14.15% (6.1 k) DUP group a higher percentage increase, 23.53% (10 kg) Although the DUP group showed a high percentage increase in strength for bench press, leg press 45g, and arm curl there were no significant differences found between LP and DUP groups. Weekly undulating periodisation (WUP) had been introduced into the literature. LP and DUP were compared against it. The program lasted nine weeks in duration. The findings were that between all three groups who participated there was no significant difference but a significant difference. DUP had a higher percentage increase in bench press and leg press, and reports of Rate of perceived exertion (RPE) increased over time compared to that of the other two groups (WUP and LP) where they found that the RPE had decreased over time. The sample was a mix of men and women were unevenly matched. Due to the difference in physiological factors of muscle growth rate in men and women the results would not provide solid significance to support previous conclusions. (BUFORD et al., 2007).

A systematic review and a meta-analysis were conducted by Harris et al. (2015) on the effectiveness of different periodisation models on the lower body and upper body for muscular strength. 17 Articles were included. 12 studies compared effectiveness Resistance training (RT), DUP and LP. 3 Studies compared RT, UP and WUP. The meta-analysis showed no apparent difference across the board. Majority of studies found no significant differences between LP and DUP in strength training amongst men, trained or untrained. There are still conflicting views on which model is superior within the literature Baker et al. and Buford et al. finding no benefits to DUP and Rhea et al. and Prestes found that DUP can enhance strength. However, DUP and LP both increase strength. There is limited evidence to suggest one is superior over the other. Advantages came with both the models of periodisaion but on particular body regions for the different models. Data found in the majority of cases there was an advantage in the squat with LP model and the DUP model had slight advantages in bench press which can be considered in future programming. Further studies need to be conducted with more emphasis on controlling the variables for volume and intensity. From the current literature there seems to be a lack of evidence or participation in studies because testing for these sort of studies would require an athlete to participate at time where they possibly are wanting to be at peak performance but either them or their coach do not want to risk a trial ruining their athletic development.

Information sources and search strategy Comprehensive search on 20th July 2018 of three electronic databases was used to conduct the research, SPORTS Discus, Pubmed and Usearch. Various keywords were used in each search. Words that have an association with the main keywords were included in the topic which was relevant to the study.

EBSCO main keywords used: Periodisation OR Periodization AND Linear OR Non-linear AND Strength training Pubmed main keywords used: ((((linear periodisation) AND non-linear periodisation) AND men) AND strength training Usearch main keywords used: Undulating OR Linear Periodisation AND Non-linear periodisation AND Strength training, Comparison. Men AND resistance training. On all three databases, BOOLEAN/PHRASE and the various criteria for the search builder all included; Abstracts and article titles were checked for initial search for relevance to the subject (20/07/2018) and full-text academic peer-reviewed journal articles were used to carry out the critical review with a further search on 24th July 2018.

Inclusion/Exclusion criteria

A restriction on the background of the generic subject area had not been put on originally to obtain a relevant history of the subject, which in some cases is still relevant to the research today. When searching more specific to the studies interests a restriction of the last ten years (2008 – 2018) was placed for the most up to date literature available to be considered for inclusion. Comparative studies of different types of periodisation were included, some with different terminology to ‘linear’ and non-linear’ as authors use some of the words interchangeably. ‘Undulating’ (Non-linear) is one example. Individual who had taken part in studies being used were Men, where no specific age range was stated and could be trained or untrained to qualify for inclusion. Systematic reviews and meta-analysis are considered to be the highest hierarchy of evidence so were included. How high up the evidence hierarchy the evidence obtained is a priority in evidence-based medicine to enable the reader a guide to interpreting the results effectively to make an informed evidence-based conclusion.

The Cochrane review is used to review systematic reviews and meta-analysis using scoring system criteria. A study which is being evaluated is graded to identify any risk of bias in the study. Things included in the risk of bias are unreliable data reporting where an author may not be being totally transparent when reporting data and picking out selected data which may fit their bias. Whether a study has been blinded or not (allocation concealment), were groups controlled? Or standardized? If not stated it makes results hard to interpret and difficult for a reader to be able to make a clear judgement without the full facts. The studies can be graded unclear, low or high risk.

Critical Appraisal

To assess how trustworthy a study is The critical appraising skills program (CASP) tool was used in order to help decide if an article will get the results the reader is looking for. With the use of these tools, it helps determine how important particular evidence is. CASP tools can be used with randomised controlled trials, systematic reviews, case studies, cohort studies and the majority of academic literature where there is a checklist you can undertake to help with your decision of whether the information in a particular article is useful to you.