Rebecca Kudrna

Short-wave diathermy pretreatment and inflammatory myokine response after high-intensity eccentric exercise

CONTEXT Various modalities have been used to pretreat skeletal muscle to attenuate inflammation. OBJECTIVE To determine the effects of short-wave diathermy (SWD) preheating treatment on inflammation and stress markers after eccentric exercise. DESIGN Controlled laboratory study. SETTING University laboratory setting. PATIENTS OR OTHER PARTICIPANTS Fifteen male (age = 22 ± 4.9 years, height = 179.75 ± 9.56 cm, mass = 82.22 ± 12.67 kg) college-aged students. INTERVENTION(S) Seven participants were selected randomly to receive 40 minutes of SWD heat treatment (HT), and 8 participants served as the control (CON) group and rested without SWD. Both groups completed 7 sets of 10 repetitions of a high-intensity eccentric exercise protocol (EEP) at 120% of the 1-repetition maximum (1-RM) leg extension. MAIN OUTCOME MEASURE(S) We biopsied muscles on days 1, 3 (24 hours post-EEP), and 4 (48 hours post-EEP) and collected blood samples on days 1, 2 (4 hours post-EEP), 3, and 4. We determined 1-RM on day 2 (24 hours post-SWD) and measured 1-RM on days 3 and 4. We analyzed the muscle samples for interleukin 6 (IL-6), tumor necrosis factor α, and heat shock protein 70 and the blood for serum creatine kinase. RESULTS We found a group × time interaction for intramuscular IL-6 levels after SWD (F2,26 = 7.13, P = .003). The IL-6 decreased in HT (F1,6 = 17.8, P = .006), whereas CON showed no change (P > .05). We found a group × time interaction for tumor necrosis factor α levels (F2,26 = 3.71, P = .04), which increased in CON (F2,14 = 7.16, P = .007), but saw no changes for HT (P > .05). No group × time interactions were noted for 1-RM, heat shock protein 70, or creatine kinase (P > .05). CONCLUSIONS The SWD preheating treatment provided a treatment effect for intramuscular inflammatory myokines induced through high-intensity eccentric exercise but did not affect other factors associated with intense exercise and inflammation.

Acute Endocrine Responses to Maximal Velocity Barbell Squats with Three Different Loads

Many strength and conditioning programs incorporate high power speed squats as part of the training regimen. The training specificity principle suggests that high power speed squats contribute to high power performance during sports performance, most likely due to the recruitment strategies required. What are not clear are the acute endocrine responses that result from this type of exercise. PURPOSE: To determine the acute endocrine responses to maximal velocity barbell squats at three different external loads. METHODS: Seven healthy recreationally weight trained men (X 6 SE; age = 21.4 6 0.6 yrs, hgt. = 1.83 6 0.02 m, wgt. = 92.0 6 3.7 kg, squat 1 RM = 152.7 6 13.4 kg) completed each of three speed squat protocols in randomized order on nonconsecutive days. The three lifting protocols were as follows; 5 3 3 at 90% 1 RM (heavy), 5 3 5 at 70% 1 RM (medium) and 5 3 10 at 30% 1 RM (light). Blood samples obtained from an antecubital vein pre-exercise (Pre) and 5 min. post-exercise (Post) were analyzed for lactate (HLa), total testosterone (Tes), cortisol (Cort) and immunoreactive growth hormone (GH). Data were analyzed using 2 x 3 (time 3 load) or 1 3 3 (3 loads) repeated measures ANOVAs (*p,0.05 vs. pre, †p,0.05 vs. light load). Data are reported as X 6 SE. RESULTS: Mean power for all repetitions at each load were; heavy = 1,071.7 6 57.6 W, medium = 1,244.2 6