thickness and 100-m-sprint performance. However, according to the findings of Hoshikawa et al, 2 the quadriceps femoris muscle cross-sectional area (CSA) for junior male sprinters was negatively correlated to 100-m-sprint performance. For the psoas major muscle, Copaver et al 1 observed significant
Norihide Sugisaki, Kai Kobayashi, Hiroyasu Tsuchie and Hiroaki Kanehisa
Conall F. Murtagh, Christopher Nulty, Jos Vanrenterghem, Andrew O’Boyle, Ryland Morgans, Barry Drust and Robert M. Erskine
maximum muscle power. Indeed, quadriceps femoris M vol has been shown to be strongly related to mean power produced during bilateral vertical CMJs in adults and children ( r 2 = .9) 6 and moderately related in male children alone ( r 2 = .3). 7 Nonetheless, bilateral vertical CMJ performance is not
Janne Sallinen, Arto Pakarinen, Mikael Fogelholm, Elina Sillanpää, Markku Alen, Jeff S. Volek, William J. Kraemer and Keijo Häkkinen
This study examined the effects of strength training and diet on serum basal hormone concentrations and muscle mass in aging women. Fifty-one women age 49 to 74 y were divided into two groups: strength training and nutritional counseling (n = 25), and strength training (n = 26). Both groups performed strength training twice a week for 21 wk. Nutritional counseling was given to attain sufficient energy and protein intake and recommended intake of fat and fiber. We found that the cross-sectional area of the quadriceps femoris increased by 9.5 ± 4.1% in the nutritional counseling group versus 6.8 ± 3.5% in the strength training only group after training (P < 0.052). Nutritional counseling evoked dietary changes such as increases in the proportion of energy from protein and the ratio of poly-unsaturated and saturated fatty acids. Strength training increased testosterone and testosterone/sex hormone-binding globulin ratio after the first half of training, but these returned to baseline values at the end of the entire training period. Changes in serum basal hormone concentrations did not differ between the groups. Our results support the conclusion that nutritional counseling can contribute to the increase in the muscle cross-sectional area during prolonged strength training in aging women.
Yanita McLeay, Stephen R Stannard, Toby Mundel, Andrew Foskett and Matthew Barnes
This study was designed to investigate the effects of alcohol consumption on recovery of muscle force when consumed immediately postexercise in young females. Eight young women completed 300 maximal eccentric actions of the quadriceps femoris muscle on an isokinetic dynamometer on two occasions in a randomized, cross-over design after which an alcoholic beverage (0.88g ethanol/kg body weight) or an iso-caloric placebo was consumed. Maximal isokinetic (concentric and eccentric) torque and isometric tension produced across the knee were measured in both the exercised and control leg predamage, 36 hr post, and 60 hr post damage. Venous blood creatine kinase (CK) activity and muscle soreness ratings were taken before damage and once per day to 60 hr post damage. Significant differences were observed between the exercised and control leg for maximal concentric, and eccentric torque and isometric tension (p < .05). A near significant Treatment × Time interaction was observed for isometric tension (p = .077), but not for concentric or eccentric torque. No main effects of treatment (alcohol) or interactions with Time × Leg or Leg × Treatment were observed. Perceived muscle soreness during box stepping and squatting showed significant time effects (p < .05), and CK activity did not significantly change. Our results indicate that the consumption of 0.88g ethanol/kg body weight following eccentric exercise-induced muscle damage does not affect recovery in the days following damage in females.
Matheus Barbalho, Victor Silveira Coswig, James Steele, James P. Fisher, Jurgen Giessing and Paulo Gentil
To compare the effects of different resistance training volumes on muscle performance and hypertrophy in trained men.
37 volunteers performed resistance training for 24 weeks, divided into groups that performed five (G5), 10 (G10), 15 (G15) and 20 (G20) sets per muscle group per week. Ten repetition maximum (10RM) tests were performed for the bench press, lat pull down, 45º leg press, and stiff legged deadlift. Muscle thickness (MT) was measured using ultrasound at biceps brachii, triceps brachii, pectoralis major, quadriceps femoris and gluteus maximus. All measurements were performed at the beginning (pre) and after 12 (mid) and 24 weeks (post)
All groups showed significant increases in all 10RM tests and MT measures after 12 and 24 weeks when compared to pre (p <0.05). There were no significant differences in any 10RM test or changes between G5 and G10 after 12 and 24 weeks. G5 and G10 showed significantly greater increases for 10RM than G15 and G20 for most exercises at 12 and 24 weeks. There were no group by time interaction for any MT measure
The results bring evidence of an inverted “U shaped” curve for the dose response curve for muscle strength. Whilst the same trend was noted for muscle hypertrophy, the results did not reach significance. Five to 10 sets per week might be sufficient for bringing about optimal gains in muscle size and strength in trained men over a 24-week period.
Matthew David Cook, Stephen David Myers, John Stephen Michael Kelly and Mark Elisabeth Theodorus Willems
Impaired glucose tolerance was shown to be present 48 hr following muscle-damaging eccentric exercise. We examined the acute effect of concentric and muscle-damaging eccentric exercise, matched for intensity, on the responses to a 2-hr 75-g oral glucose tolerance test (OGTT). Ten men (27 ± 9 years, 178 ± 7 cm, 75 ± 11 kg, VO2max: 52.3 ± 7.3 ml·kg-1·min-1) underwent three OGTTs after an overnight 12 hr fast: rest (control), 40-min (5 × 8-min with 2-min interbout rest) of concentric (level running, 0%, CON) or eccentric exercise (downhill running, –12%, ECC). Running intensity was matched at 60% of maximal metabolic equivalent. Maximal isometric force of m. quadriceps femoris of both legs was measured before and after the running protocols. Downhill running speed was higher (level: 9.7 ± 2.1, downhill: 13.8 ± 3.2 km·hr-1, p < .01). Running protocols had similar VO2max (p = .59), heart rates (p = .20) and respiratory exchange ratio values (p = .74) indicating matched intensity and metabolic demands. Downhill running resulted in higher isometric force deficits (level: 3.0 ± 6.7, downhill: 17.1 ± 7.3%, p < .01). During OGTTs, area-under-the-curve for plasma glucose (control: 724 ± 97, CON: 710 ± 77, ECC: 726 ± 72 mmol·L-1·120 min, p = .86) and insulin (control: 24995 ± 11229, CON: 23319 ± 10417, ECC: 21842 ± 10171 pmol·L-1·120 min, p = .48), peak glucose (control: 8.1 ± 1.3, CON: 7.7 ± 1.2, ECC: 7.7 ± 1.1 mmol·L-1, p = .63) and peak insulin levels (control: 361 ± 188, CON: 322 ± 179, ECC: 299 ± 152 pmol·L-1, p = .30) were similar. It was concluded that glucose tolerance and the insulin response to an OGTT were not changed immediately by muscle-damaging eccentric exercise.
Ilkka Heinonen, Jukka Kemppainen, Toshihiko Fujimoto, Juhani Knuuti and Kari K. Kalliokoski
Figure 1 . The average GU values of these regions of interests from both legs were used when presenting data. Skeletal muscle GU was calculated in m. quadriceps femoris muscle group, as it is the most active muscle group during cycling. Figure 1 —Representative cross-sectional positron emission
Daria Neyroud, Jimmy Samararatne, Bengt Kayser and Nicolas Place
and neuromuscular responses between voluntary and stimulated contractions of the quadriceps femoris muscle . Respir Physiol Neurobiol . 2007 ; 157 : 341 – 347 . PubMed doi:10.1016/j.resp.2006.12.002 17210271 10.1016/j.resp.2006.12.002 6. Lieber RL , Kelly MJ . Torque history of electrically
Dustin J. Oranchuk, André R. Nelson, Adam G. Storey and John B. Cronin
: 28805932 doi: 10.1111/sms.12961 28805932 8. Ando R , Saito A , Umemura Y , Akima H . Local architecture of the vastus intermedius is a better predictor of knee extension force than that of the other quadriceps femoris muscle heads . Clin Physiol Funct Imaging . 2014 ; 35 ( 5 ): 376 – 382
Benjamin Pageaux, Jean Theurel and Romuald Lepers
. PubMed doi:10.1249/MSS.0000000000000448 10.1249/MSS.0000000000000448 25051388 13. Babault N , Pousson M , Ballay Y , Van Hoecke J . Activation of human quadriceps femoris during isometric, concentric, and eccentric contractions . J Appl Physiol . 2001 ; 91 ( 6 ): 2628 – 2634 . PubMed