I hope you guys have had an awesome week and are ready for the weekend – I sure know I am after an insanely intense week in the hospital. First of all, thanks for all the awesome positive feedback I’ve been getting over the last few days on my last article Why I Refuse To Help You Lose Fat – Even If I Can – your feedback means more then you could understand. If you missed it, make sure to click the link above.
Now to the topic of the day: I’ve noticed that the science post I post on Twitter, Facebook and Google+ always generate a lot of clicks and that there seems to a huge interest among my followers for the nerdy part of fitness. So I thought it would be a good idea to collect the interesting research I come over during the week in a Geeky Friday post, just so you don’t miss out on anything. At this point I won’t make any reviews of the research myself (wish I could, but I just don’t have the time at this point). Instead, I will basically copy-paste the abstracts of the studies I come in contact with and with the links to pubmed and you can cherry pick the studies you’re interested in, or just read all the abstracts here and settle with that.
Please let me know if you think this is a good idea and I’ll make sure I keep providing you with 10-ish new interesting studies I’ve come over during the week every Friday. And make sure you spread the knowledge by sharing the articles on whichever social media you might be addicted to.
Some interesting studies from last week:
Int J Endocrinol. 2012;2012:962012
Authors: Belkacemi L, Selselet-Attou G, Hupkens E, Nguidjoe E, Louchami K, Sener A, Malaisse WJ
Abstract: This study investigates the effects of intermittent overnight fasting in streptozotocin-induced diabetic rats (STZ rats). Over 30 days, groups of 5-6 control or STZ rats were allowed free food access, starved overnight, or exposed to a restricted food supply comparable to that ingested by the intermittently fasting animals. Intermittent fasting improved glucose tolerance, increased plasma insulin, and lowered Homeostatis Model Assessment index. Caloric restriction failed to cause such beneficial effects. The β-cell mass, as well as individual β-cell and islet area, was higher in intermittently fasting than in nonfasting STZ rats, whilst the percentage of apoptotic β-cells appeared lower in the former than latter STZ rats. In the calorie-restricted STZ rats, comparable findings were restricted to individual islet area and percentage of apoptotic cells. Hence, it is proposed that intermittent fasting could represent a possible approach to prevent or minimize disturbances of glucose homeostasis in human subjects.
J Strength Cond Res. 2012 Feb 3;
Authors: Row BS, Knutzen KM, Skogsberg NJ
Abstract: Explosive resistance training (ERT) improves older adults’ strength and power, and methods to make this form of training more accessible and useful to older adults are needed. The purpose of this study was to evaluate whether the rating of perceived exertion (RPE) scale would predict a broad range of ERT intensities on the leg press with older adults. If successful, then a load-RPE relationship could be used to regulate the intensity of training loads for ERT with older adults, allowing the elimination of maximal strength testing. Twenty-one older adults (≥65 years) with resistance training experience took part in 2 testing sessions. Session 1: Subjects performed high-velocity repetitions on the leg press for up to 9 loads (from 60 to 140% body weight) presented in quasi-randomized order, and then reported their RPE for each load. Session 2: A 1 repetition maximum (1RM) strength test was conducted. Regression analysis revealed that the average RPE across subjects for each load strongly predicted the average %1RM across subjects (R = 99.5%; p < 0.001). This allows the establishment of a load-RPE relationship for use in selecting ERT loads for older adults on the leg press. For example, high-intensity loads (70-90% 1RM) that would elicit both strength and power gains when used with ERT aligned with an RPE of 14-16. Lighter loads that may be useful for training for power, but not strength (
J Strength Cond Res. 2012 Feb 3;
Authors: Kon M, Ikeda T, Homma T, Suzuki Y
Abstract: Previous studies have shown that low-intensity resistance exercises with vascular occlusion and slow movement effectively increase muscular size and strength. Researchers have speculated that local hypoxia by occlusion and slow movement may contribute to such adaptations via promoting anabolic hormone secretions by the local accumulation of metabolites. In this study, we determined the effects of low-intensity resistance exercise under acute systemic hypoxia on metabolic and hormonal responses. Eight male subjects participated in 2 experimental trials: (a) low-intensity resistance exercise while breathing normoxic air (normoxic resistance exercise [NR]), (b) low-intensity resistance exercise while breathing 13% oxygen (hypoxic resistance exercise [HR]). The resistance exercises (bench press and leg press) consisted of 14 repetitions for 5 sets at 50% of maximum strength with 1 minute of rest between sets. Blood lactate (LA), serum growth hormone (GH), norepinephrine (NE), testosterone, and cortisol concentrations were measured before normoxia and hypoxia exposures; 15 minutes after the exposures; and at 0, 15, and 30 minutes after the exercises. The LA levels significantly increased after exercises in both trials (p ≤ 0.05). The area under the curve for LA after exercises was significantly higher in the HR trial than in the NR trial (p ≤ 0.05). The GH significantly increased only after the HR trial (p ≤ 0.05). The NE and testosterone significantly increased after the exercises in both trials (p ≤ 0.05). Cortisol did not significantly change in both trials. These results suggest that low-intensity resistance exercise in the hypoxic condition caused greater metabolic and hormonal responses than that in the normoxic condition. Coaches may consider low-intensity resistance exercise under systemic hypoxia as a potential training method for athletes who need to maintain muscle mass and strength during the long in-season.
Effect of strength training and the practice of Alpine skiing on bone mass density, growth, body composition, and the strength and power of the legs of adolescent skiers.
J Strength Cond Res. 2011 Oct;25(10):2879-90
Authors: Alvarez-San Emeterio C, Antuñano NP, López-Sobaler AM, González-Badillo JJ
Abstract: This work examines the influence of practicing strength training and Alpine skiing over 2 years on bone mineral density (BMD), growth, body composition, and the strength and power of the legs of adolescent skiers. The study subjects were 20 adolescent skiers (10 girls and 10 boys) and 19 sedentary adolescents (9 girls and 10 boys), all 13-16 years of age. The BMDs of the lumbar column (L2-L4) and hip (neck of the femur, trochanter, and Ward’s triangle) were determined by dual x-ray photon absorptiometry at the beginning and end of the experimental period. The increase in height and the percentage fat and muscular masses of the subjects were also recorded, as was their ability to jump (countermovement jump [CMJ]), their leg strength and power (squat test), and their leg anaerobic power (continuous jump test [CMJ15″]). No significant differences were seen in the increase in height, body weight, or percentage fat mass between the skiers and sedentary subjects, although the boy skiers showed a significant increase in percentage muscular mass (p < 0.05) compared to the sedentary boys. The improvement in the values of the different CMJ variables was significantly greater among the boy skiers than among the sedentary boys (p < 0.001-0.01). The same was true for the girls (p < 0.001), except for CMJ15″. The skiers experienced a significantly greater increase in L2-L4 BMD than the sedentary subjects (boys p < 0.05; girls p < 0.01). These results suggest that Alpine skiing combined with rational strength training involves no special risk for the physical development of young people, has a positive effect on the power and the percentage of muscle mass in the legs, and helps to have a higher bone density in the lumbar spine (L2-L4).
Med Hypotheses. 2012 Feb 2;
Authors: Loenneke JP, Young KC, Fahs CA, Rossow LM, Bemben DA, Bemben MG
Abstract: Low intensity exercise with blood flow restriction has been shown to increase muscle hypertrophy and strength similar to high intensity resistance exercise. Interestingly, low intensity resistance exercise to failure has shown the same muscle protein synthesis response as higher intensity exercise, questioning the need for blood flow restriction during low intensity exercise. The purpose of this manuscript is to discuss the mechanisms and potential benefits of blood flow restricted exercise on bone adaptation and provide rationale as to why low load resistance exercise to failure would be unlikely to produce these benefits. The studies completed thus far support the hypothesis that training with blood flow restriction may provide not only a novel modality to induce adaptation in muscle but also bone, which was previously thought to only occur with higher intensity/impact exercise. We hypothesize that the main mechanism behind the proposed favorable bone responses observed thus far is through increased intramedullary pressure and interstitial fluid flow within the bone caused by venous occlusion. Therefore, although similar muscular benefits may be observed from low intensity exercise performed to failure (e.g. strength, hypertrophy, and endurance), the response of bone might be different, highlighting the potential importance of the blood flow restriction stimulus.
Nestle Nutr Inst Workshop Ser. 2011;69:79-95
Authors: van Loon LJ, Gibala MJ
Abstract: Intact protein, protein hydrolysates, and free amino acids are popular ingredients in contemporary sports nutrition, and have been suggested to augment post-exercise recovery. Protein and/or amino acid ingestion stimulates skeletal muscle protein synthesis, inhibits protein breakdown and, as such, stimulates muscle protein accretion following resistance and endurance type exercise. This has been suggested to lead to a greater adaptive response to each successive exercise bout, resulting in more effective muscle reconditioning. Despite limited evidence, some basic guidelines can be defined regarding the preferred type, amount, and timing of dietary protein that should be ingested to maximize post-exercise muscle protein accretion. Whey protein seems most effective in stimulating muscle protein synthesis during acute post-exercise recovery. This is likely attributable to its rapid digestion and absorption kinetics and specific amino acid composition. Ingestion of approximately 20 g protein during and/or immediately after exercise is sufficient to maximize post-exercise muscle protein synthesis rates. Coingestion of a large amount of carbohydrate or free leucine is not warranted to further augment post- exercise muscle protein synthesis when ample protein is already ingested. Future research should focus on the relevance of the acute anabolic response following exercise to optimize the skeletal muscle adaptive response to exercise training.
Sports Med. 2012 Feb 1;
Authors: Simão R, de Salles BF, Figueiredo T, Dias I, Willardson JM
Abstract: Resistance training (RT) is now an integral component of a well rounded exercise programme. For a correct training prescription, it is of the utmost importance to understand the interaction among training variables, such as the load, volume, rest interval between sets and exercises, frequency of sessions, exercise modality, repetition velocity and, finally, exercise order. Sports medicine research has indicated that exercise order is an important variable that affects both acute responses and chronic adaptations to RT programmes. Therefore, the purpose of this review was to analyse and discuss exercise order with relevance to acute responses (e.g. repetition performance) and also the expression of chronic adaptable characteristics (e.g. maximal strength and hypertrophy). To accomplish this purpose, the Scielo, Science Citation Index, National Library of Medicine, MEDLINE, Scopus, SPORTDiscus™ and CINAHL® databases were accessed to locate previously conducted original scientific investigations. The studies reviewed examined both acute responses and chronic adaptations with exercise order as the experimental variable. Generally, with relevance to acute responses, a key finding was that exercise order affects repetition performance over multiple sets, indicating that the total repetitions, and thus the volume, is greater when an exercise is placed at the beginning of an RT session, regardless of the relative amount of muscle mass involved. The pre-exhaustion method might not be an effective technique to increase the extent of neuromuscular recruitment for larger muscle groups (e.g. pectoralis major for the bench press) when preceded by a single-joint movement (e.g. pec-deck fly). With relevance to localized muscular endurance performance, oxygen consumption and ratings of perceived exertion, the limited amount of research conducted thus far indicates that exercise order does not appear to impact the acute expression of these variables. In terms of chronic adaptations, greater strength increases were evident by untrained subjects for the first exercise of a given sequence, while strength increases were inhibited for the last exercise of a given sequence. Additionally, based on strength and hypertrophy (i.e. muscle thickness and volume) effect-size data, the research suggests that exercises be ordered based on priority of importance as dictated by the training goal of a programme, irrespective of whether the exercise involves a relatively large or small muscle group. In summary, exercise order is an important variable that should receive greater attention in RT prescription. When prescribed appropriately with other key prescriptive variables (i.e. load, volume, rest interval between sets and exercises), the exercise order can influence the efficiency, safety and ultimate effectiveness of an RT programme.
J Strength Cond Res. 2012 Jan 26;
Authors: Zavanela PM, Crewther BT, Lodo L, Florindo AA, Miyabara EH, Aoki MS
Abstract: This study examined the effects of a workplace-based resistance training intervention on different health-, fitness-, and work-related measures in untrained men (bus drivers). The subjects were recruited from a bus company and divided into a training (n = 48) and control (n = 48) groups after initial prescreening. The training group performed a 24-week resistance training program, whereas the control group maintained their normal daily activities. Each group was assessed for body composition, blood pressure (BP), pain incidence, muscular endurance, and flexibility before and after the 24-week period. Work absenteeism was also recorded during this period and after a 12-week follow-up phase. In general, no body composition changes were identified in either group. In the training group, a significant reduction in BP and pain incidence, along with improvements in muscle endurance and flexibility were seen after 24 weeks (p < 0.05). There were no changes in these parameters in the control group, and the between-group differences were all significant (p < 0.05). A reduction in worker absenteeism rate was also noted in the training (vs. control) group during both the interventional and follow-up periods (p < 0.05). In conclusion, it was found that a periodized resistance training intervention performed within the workplace improved different aspects of health and fitness in untrained men, thereby potentially providing other work-related benefits. Thus, both employers and employees may benefit from the setup, promotion, and support of a work-based physical activity program involving resistance training.
And just to celebrate the first edition of Geeky Friday – here’s my favorite study of all time and this week’s WTF? – study :
Arch Sex Behav. 2002 Jun;31(3):289-93;
Authors: Gallup GG Jr, Burch RL, Platek SM.
In a sample of sexually active college females, condom use, as an indirect measure of the presence of semen in the reproductive tract, was related to scores on the Beck Depression Inventory. Not only were females who were having sex without condoms less depressed, but depressive symptoms and suicide attempts among females who used condoms were proportional to the consistency of condom use. For females who did not use condoms, depression scores went up as the amount of time since their last sexual encounter increased. These data are consistent with the possibility that semen may antagonize depressive symptoms and evidence which shows that the vagina absorbs a number of components of semen that can be detected in the bloodstream within a few hours of administration.
Take care of you all.