The purpose of this study was to assess the physiological responses of former elite distance runners during submaximal and maximal exercise after a mean period of 22 yr. Fifty-three men were initially tested (T1) in the late 1960s and early 1970s when they were all highly trained and competitive. For the current evaluation (T2), these men were classified as highly trained (HT; n = 10), fitness trained (FT; n = 18), untrained (UT; n = 15), and fit older (FO; n = 10), depending on their continued level of training and age. The mean (+/- SE) age for the HT, FT, and UT men during T2 was similar (46.5 +/- 1.6 yr), whereas the FO men were significantly (P < 0.05) older (68.4 +/- 2.7 yr). All groups experienced a significant decrease (P < 0.05) in maximal O2 uptake (VO2 max) from T1 to T2. However, this decrease was related to the amount of training between evaluations. The HT men had the smallest reduction (6% per decade) in VO2 max (from 68.8 to 59.2 ml.g-1.min-1). The FT men's VO2 max was approximately 10% lower per decade (from 64.1 to 48.9 ml.kg-1.min-1), whereas an approximately 15% decrease per decade was observed for the UT (from 70.7 to 46.7 ml.kg-1.min-1) and FO (from 60.3 to 40.7 ml.kg-1.min-1) men, despite the continued training of the FO men. Energy requirements for a standardized run at 12 km/run were similar from T1 to T2 for the HT and FT men, whereas the UT men required an increased (P < 0.05) O2 uptake (40.3-41.8 l/min), ventilation (53.7-72.7 l/min), and heart rate (127-142 beats/min). The perceived effort and %VO2 max for this submaximal run were greater during T2 for all groups, which was related to the decline in VO2 max. These longitudinal data indicate that after more than two decades the physiological capacities of these aging runners are compromised, regardless of training. These data also confirm previous cross-sectional findings that aerobic capacity of highly trained middle-aged men declines approximately 5-7% per decade.

Studies in young adults have demonstrated that beta-hydroxy-beta-methylbutyrate (HMB) can increase gains in strength and fat-free mass during a progressive resistance-training program. The purpose of this study was to determine whether HMB would similarly benefit 70-y-old adults undergoing a 5 d/wk exercise program. Thirty-one men (n = 15) and women (n = 16) (70 +/- 1 y) were randomly assigned in a double-blind study to receive either capsules containing a placebo or Ca-HMB (3 g/d) for the 8-wk study. Skin fold estimations of body composition as well as computerized tomography (CT) and dual X-ray absorptiometry (DXA) scans were measured before the study and immediately after the 8-wk training program. HMB supplementation tended to increase fat-free mass gain (HMB, 0.8 +/- 0.4 kg; placebo, -0.2 +/- 0.3 kg; treatment x time, P = 0.08). Furthermore, HMB supplementation increased the percentage of body fat loss (skin fold: HMB, -0.66 +/- 0.23%; placebo, -0.03 +/- 0.21%; P = 0.05) compared with the placebo group. CT scans also indicated a greater decrease in the percentage of body fat with HMB supplementation (P < 0.05). In conclusion, changes in body composition can be accomplished in 70-y-old adults participating in a strength training program, as previously demonstrated in young adults, when HMB is supplemented daily.

Androstenedione supplementation does not increase serum testosterone concentrations or enhance skeletal muscle adaptations to resistance training in normotestosterogenic young men and may result in adverse health consequences.

The leucine metabolite, beta-hydroxy-beta-methylbutyrate (HMB) enhances the effects of exercise on muscle size and strength. Although several reports in animals and humans indicate that HMB is safe, quantitative safety data in humans have not been reported definitively. The objective of this work was to summarize safety data collected in nine studies in which humans were fed 3 g HMB/d. The studies were from 3 to 8 wk in duration, included both males and females, young and old, exercising or nonexercising. Organ and tissue function was assessed by blood chemistry and hematology; subtle effects on emotional perception were measured with an emotional profile test (Circumplex), and tolerance of HMB was assessed with a battery of 32 health-related questions. HMB did not adversely affect any surrogate marker of tissue health and function. The Circumplex emotion profile indicated that HMB significantly decreased (improved) one indicator of negative mood (Unactivated Unpleasant Affect category, P < 0.05). No untoward effects of HMB were indicated. Compared with the placebo, HMB supplementation resulted in a net decrease in total cholesterol (5.8%, P < 0.03), a decrease in LDL cholesterol (7.3%, P < 0.01) and a decrease in systolic blood pressure (4.4 mm Hg, P < 0.05). These effects of HMB on surrogate markers of cardiovascular health could result in a decrease in the risk of heart attack and stroke. In conclusion, the objective data collected across nine experiments indicate that HMB can be taken safely as an ergogenic aid for exercise and that objective measures of health and perception of well-being are generally enhanced.

BackgroundWhile it is well established that dietary nitrate reduces the metabolic cost of exercise, recent evidence suggests this effect is maintained 24 h following the final nitrate dose when plasma nitrite levels have returned to baseline. In addition, acute dietary nitrate was recently reported to enhance peak power production. Our purpose was to examine whether chronic dietary nitrate supplementation enhanced peak power 24 h following the final dose and if this impacted performance in a heavily power-dependent sport.MethodsIn a double-blind, randomized, crossover design, maximal aerobic capacity, body composition, strength, maximal power (30 s Wingate), endurance (2 km rowing time trial), and CrossFit performance (Grace protocol) were assessed before and after six days of supplementation with nitrate (NO) (8 mmol·potassium nitrate·d−1) or a non-caloric placebo (PL). A 10-day washout period divided treatment conditions. Paired t-tests were utilized to assess changes over time and to compare changes between treatments.ResultsPeak Wingate power increased significantly over time with NO (889.17 ± 179.69 W to 948.08 ± 186.80 W; p = 0.01) but not PL (898.08 ± 183.24 W to 905.00 ± 157.23 W; p = 0.75). However, CrossFit performance was unchanged, and there were no changes in any other performance parameters.ConclusionConsuming dietary nitrate in the potassium nitrate salt form improved peak power during a Wingate test, but did not improve elements of strength or endurance in male CrossFit athletes.