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Purpose and Methods: To test whether heat training performed as 5 × 50-min sessions per week for 5 wk in a heat chamber (CHAMBER) or while wearing a heat suit (SUIT), in temperate conditions, increases hemoglobin mass (Hb mass ) and endurance performance in elite cyclists, compared with a control group (CON-1). Furthermore, after the 5-wk intervention, we tested whether three sessions per week for 3 wk with heat suit (SUIT main ) would maintain Hb mass elevated compared with athletes who returned to normal training (HEAT stop ) or who continued to be the control group (CON-2)., Results: During the initial 5 wk, SUIT and CHAMBER increased Hb mass (2.6% and 2.4%) to a greater extent than CON-1 (-0.7%; both P < 0.01). The power output at 4 mmol·L -1 blood lactate and 1-min power output ( Wmax ) improved more in SUIT (3.6% and 7.3%, respectively) than CON-1 (-0.6%, P < 0.05; 0.2%, P < 0.01), whereas this was not the case for CHAMBER (1.4%, P = 0.24; 3.4%, P = 0.29). However, when SUIT and CHAMBER were pooled this revealed a greater improvement in a performance index (composed of power output at 4 mmol·L -1 blood lactate, Wmax , and 15-min power output) than CON-1 (4.9% ± 3.2% vs 1.7% ± 1.1%, respectively; P < 0.05). During the 3-wk maintenance period, SUIT main induced a larger increase in Hb mass than HEAT stop (3.3% vs 0.8%; P < 0.05), which was not different from the control (CON-2; 1.6%; P = 0.19), with no differences between HEAT stop and CON-2 ( P = 0.52)., Conclusions: Both SUIT and CHAMBER can increase Hb mass , and pooling SUIT and CHAMBER demonstrates that heat training can increase performance. Furthermore, compared with cessation of heat training, a sustained increase in Hb mass was observed during a subsequent 3-wk maintenance period, although the number of weekly heat training sessions was reduced to 3., (Copyright © 2022 by the American College of Sports Medicine.)

Background: A rapid digestibility and high leucine content are considered important for maximal stimulation of muscle protein synthesis. Consequently, with these properties, native whey may hold greater anabolic potential than milk, when supplemented in combination with strength training. Our aim was to compare the effects of supplementation with milk or native whey, during a 12-wk strength training period, on gains in muscle mass and strength in young adults., Methods: In this double-blinded, randomized, controlled study a total of 40 untrained young men and women received two daily servings of either milk or native whey containing 20 g of protein, during a 12-wk strength training intervention. Muscle strength, lean mass, thigh muscle cross-sectional area, m. vastus lateralis thickness and muscle fiber cross-sectional area were assessed before and after the training period. In addition, the acute phosphorylation of the anabolic kinases p70S6K, 4E-BP1 and eEF-2 in response to a standardized workout and supplementation was investigated before and after the 12-wk training period., Results: Muscle mass and strength increased, by all measures applied (5%-16%, P < 0.001), with no differences between groups (P > 0.25). p70S6K phosphorylation increased (~1000%, P < 0.02) 2 h after exercise in the untrained and trained state, but no differences in anabolic signaling were observed between supplements (P > 0.40). No correlation between these acute measures and changes in muscle mass or strength were observed., Conclusion: Supplementation with milk or native whey during a 12-wk strength training period did not differentially affect muscle mass and strength in young untrained individuals.

Introduction: The aim of this study was to investigate the effect of an arduous 1-wk military course on measures of physical performance, body composition, and blood biomarkers., Methods: Participants were apprentices in an annual selection course for the Norwegian Special Forces. Fifteen soldiers (23 ± 4 yr, 1.81 ± 0.06 m, 78 ± 7 kg) completed a hell week consisting of rigorous activity only interspersed by 2 to 3 h of sleep per day. Testing was conducted before and 0, 1, 3, 7, and 14 d after the hell week. Physical performance was measured as muscle strength and jump performance. Body composition was measured by bioelectrical impedance and blood samples were collected and analyzed for hormones, creatine kinase, and C-reactive protein., Results: Body mass was reduced by 5.3 ± 1.9 kg during the hell week and returned to baseline within 1 wk. Fat mass was reduced by 2.1 ± 1.7 kg and muscle mass by 1.9 ± 0.9 kg. Muscle strength in leg press and bench press was reduced by 20% ± 9% and 9% ± 7%, respectively, and both were approximately 10% lower than baseline after 1 wk of recovery. Jump-height was reduced by 28% ± 13% and was still 14% ± 5% below baseline after 2 wk of recovery. Testosterone was reduced by 70% ± 12% and recovered gradually within a week. Cortisol was increased by 154% ± 74% and did not fully recover during the next week. Insulin-like growth factor 1 was reduced by 51% ± 10% and triiodothyronine and thyroxine by 12% to 30%, all recovered within a week., Conclusions: One-week arduous military exercise resulted in reductions in body mass and performance, as well as considerable hormonal disturbances. Our most important observation was that whereas the hormonal systems was normalized within 1 wk of rest and proper nutrition, lower body strength and jump performance were still depressed after 2 wk.

Purpose: This study investigated the effects of ethanol consumption on recovery from traditional resistance exercise in recreationally trained individuals., Methods: Nine recreationally trained volunteers (eight males and one female, 26 ± 4 yr, 81 ± 4 kg) conducted four resistance exercise sessions and consumed a low (0.6 (females) and 0.7 (males) g · kg(-1) body mass) or a high dose (1.2 or 1.4 g · kg(-1) body mass) of ethanol 1-2.5 h after exercise on two occasions. The first session was for familiarization with the tests and exercises and was performed without ethanol consumption. As a control trial, alcohol-free drinks were consumed after the exercise session. The sequence of trials, with low and high ethanol doses and alcohol-free drinks (control), was randomized. Maximal voluntary contractions (MVC) (knee extension), electrically stimulated contractions (knee extension), squat jumps, and hand grip strength were assessed 10-15 min and 12 and 24 h after the ethanol/placebo drinks. In addition to a baseline sample, blood was collected 1, 12, and 24 h after the ethanol/placebo drinks. The exercise session comprised 4 × 8 repetition maximum of squats, leg presses, and knee extensions., Results: MVC were reduced by 13%-15% immediately after the exercise sessions (P < 0.01). MVC, electrically stimulated force, and squat jump performance were recovered 24 h after ethanol drinks. MVC was not fully recovered at 24 h in the control trial. Compared with those in the control, cortisol increased and the free testosterone/cortisol ratio were reduced after the high ethanol dose (P < 0.01)., Conclusions: Neither a low nor a high dose of ethanol adversely affected recovery of muscle function after resistance exercise in recreationally strength-trained individuals. However, the increased cortisol levels and reduced testosterone/cortisol ratio after the high ethanol dose could translate into long-term negative effects.