A Critical Commentary on the Practical Application of Resistance Training Studies

Abstract

11 variance between each participants' training protocol. They continue by stating that an additional quadriceps exercise of either a knee extension or leg press was performed, with a training load between 60 and 80% 1RM for 5-10 repetitions, totalling 20-40 contractions per exercise. From this detail are we to assume that stimulation and training effect of the quadriceps is equal between an isolated (knee-extension) and a compound (leg press) exercise when training with 20% greater or lesser load and performing half or double the number of repetitions and contractions? Other research has proposed that the quadriceps have significantly greater involvement in an open-chain knee-extension exercise compared to closed-chain leg press exercise 15 which suggests any such assumptions would be inaccurate. Häkkinen and Kallinen 9 continue by stating that the training program included 3 to 4 other exercises each workout for the main muscle groups of the body, however they fail to clarify what these exercises are. From both a scientific and practical aspect we should consider how useful the results from this study are if we don't know exactly what exercises, loads, repetitions, or contractions different participants performed. A further study considered muscular hypertrophy over a 12 week intervention between middle-aged and elderly participants training using a unilateral (UNIL) or bilateral (BIL) knee extension exercise. 10 The authors state that both UNIL and BIL groups trained 2 x / week for 12 weeks where the training intervention progressed every 4 weeks beginning with a load of 40-50% 1RM for 10-12 repetitions for 3-4 sets (weeks 1-4). This progressed to 60-80% 1RM for 6-8 repetitions, for 3-5 sets (weeks 5-8), and finished with a load of 70-90% 1RM for 3-6 repetitions for 4-6 sets (weeks 9-12). Again the authors did not clarify that participants trained to RM or MMF. We might consider the possible variances in training protocol between participants; for example during the first 4-week phase, one person might have performed 12 repetitions for 4 sets at 50% 1RM, whilst another might have performed 10 repetitions for 3 sets at 40% 1RM; if both participants have a hypothetical 1RM of 100kg this equates to total training volume of 2,400kg (12 x 4 x 50) and 1,200kg (10 x 3 x 40), respectively. We could further consider the magnitude this might have over the following 4-week phases, including repetitions, loads and sets over a 2 x / week, 12-week period. Each participant performed between a maximum of 70,720kg and minimum of 24,960kg of total work over the 12-week period. This shows a considerable disparity between the two training regimes and thus it is worth considering that this intra-group training variation might have been a reason for the lack of between group statistical significance. In addition other studies have simply been too vague in the training protocol; for example Ahtiainen, et al. 11 compared 8 male strength athletes (SA) against 8 physically active males (NA) measuring the hypertrophy of the quadriceps muscles following a 21 week intervention. The authors state that "large inter-individual variation was observed in the strength training programs among the present strength athletes" and also that the training program has been presented earlier. 12 However, upon review of the previous article 12 the training routine contains so many variations of load, volume, repetition duration, and exercise selection throughout the intervention, that it is simply impossible to know exactly how each participant or group of participants actually trained. Whilst the present author appreciates that this is potentially realistic in its representation of normal variation in a person's training regime, this kind of disparity between participants and groups makes accurate analysis impossible. Another study, this time considering the effects of concurrent strength and endurance training versus strength training only 13 details within the methods section that the strength training protocol included: "four to five exercises for the other main muscle groups of the body (bench press and/or the triceps pushdown and/or lateral pull-down exercise for the upper body; the sit-up exercise for the trunk flexors and/or another exercise for the trunk extensors; and the bilateral/unilateral elbow and/or knee flexion exercise and/or leg adduction/ abduction exercise)….with loads of 50% to 70% 1RM… 10-15 repetitions per set….3-4 sets of each exercise".