Time-Trial Performance in World-Class Speed Skaters After Chronic Nitrate Ingestion.

PURPOSE: Nitrate supplementation can increase tolerance to high-intensity work rates; however, limited data exist on the recovery of performance. The authors tested whether 5 d of nitrate supplementation could improve repeated time-trial performance in speed skating. METHODS: Using a double-blind, placebo-controlled, crossover design, 9 international-level short-track speed skaters ingested 1 high (juice blend, ∼6.5 mmol nitrate; HI) or low dose (juice blend, ∼1 mmol nitrate; LO) per day on days 1-4. After a double dose of either HI or LO on day 5, athletes performed 2 on-ice 1000-m time trials, separated by 35 min, to simulate competition races. Differences between HI and LO were compared with the smallest practically important difference. RESULTS: Salivary [nitrate] and [nitrite] were higher in HI than LO before the first (nitrate: 81%, effect size [ES]: 1.76; nitrite: 72%, ES: 1.73) and second pursuits (nitrate: 81%, ES: 1.92; nitrite: 71%, ES: 1.78). However, there was no difference in performance in the first (LO: 90.92 [4.08] s; HI: 90.95 [4.06] s, ES: 0.01) or the second time trial (LO: 91.16 [4.06] s; HI: 91.55 [4.40] s, ES: 0.09). Plasma [lactate] measured after the trials (LO: 14.8 [1.1] mM; HI: 14.8 [1.2] mM, ES: 0.01) and at the end of the recovery period (LO: 9.8 [2.1] mM; HI: 10.2 [1.9] mM, ES: 0.05) was not different between treatments. CONCLUSION: Five days of high-dose nitrate supplementation did not change physiological responses and failed to improve single and repeated time-trial performances in world-class short-track speed skaters. These data suggest that nitrate ingestion up to 6.5 mmol does not enhance recovery from supramaximal exercise in world-class athletes.

Chronic alcohol intake, resistance training, and muscle androgen receptor content.

INTRODUCTION: Chronic alcohol intake and resistance training (RT) have opposite effects on muscle physiology. PURPOSE: This study examined the effect of chronic alcohol intake on androgen receptor (AR) content in skeletal muscle to determine whether this effect was influenced by RT. METHODS: A total of 48 male Sprague Dawley(R) rats (mass = 456 +/- 1 g; mean +/- SE) were divided into five groups: baseline (N = 8), sedentary + alcohol (Sed-Al) (N = 8), sedentary + normal diet (Sed-Nml) (N = 8), exercise + alcohol (Ex-Al) (N = 12), and exercise + normal diet (Ex-Nml) (N = 12). Exercise groups completed a 6 1/3-wk "squat" RT protocol; alcohol groups received an ethanol-rich (35% caloric content of alcohol) diet throughout the 6 1/3-wk period. Baseline animals were killed at the onset of the 6 1/3-wk training period. RESULTS: Western blot analysis showed no effect of alcohol or RT on the AR of the extensor digitorum longus. Alcohol significantly reduced AR content of the rectus femoris (P < 0.05) and prevented RT-induced increases in AR content of the soleus. CONCLUSION: Chronic alcohol intake appeared to reduce the AR content of the type IIB fiber-predominant rectus femoris, and this reduction was not affected by RT. In the type I-predominant soleus, chronic alcohol intake alone had no effect but seemed to prevent RT-induced increases in AR content.