Dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance. Acute exposure to ultraviolet (UV)-A light also increases NO bioavailability and reduces BP. We conducted a randomized, counterbalanced placebo-controlled trial to determine the effects of UV-A light alone and in combination with nitrate on the responses to sub-maximal steady-state exercise and time trial (TT) performance. Nine cyclists (VO2max 53.1 +/- 4.4 ml/kg/min) completed five performance trials comprising 10 min submaximal steady-state cycling followed by a 16.1 km TT. Following a familiarization the final four trials were preceded, in random order, by either (1) Nitrate gels (NIT) + UV-A, (2) Placebo (PLA) + UV-A, (3) NIT + Sham light (SHAM) and (4) PLA + SHAM (control). The NIT gels (2 x 60 ml gels, ~8.1 mmol nitrate) or a low-nitrate PLA were ingested 2.5 h prior to the trial. The light exposure consisted of 20 J/cm(2) whole body irradiation with either UV-A or SHAM light. Plasma nitrite was measured pre- and post-irradiation and VO2 was measured continuously during steady-state exercise. Plasma nitrite was higher for NIT + SHAM (geometric mean (95% CI), 332 (292-377) nM; P = 0.029) and NIT + UV-A (456 (312-666) nM; P = 0.014) compared to PLA + SHAM (215 (167-277) nM). Differences between PLA + SHAM and PLA + UV-A (282 (248-356) nM) were small and non-significant. During steady-state exercise VO2 was reduced following NIT + UVA (P = 0.034) and tended to be lower in NIT + SHAM (P = 0.086) but not PLA + UV-A (P = 0.381) compared to PLA + SHAM. Performance in the TT was significantly faster following NIT + UV-A (mean +/- SD 1447 +/- 41 s P = 0.005; d = 0.47), but not PLA + UV-A (1450 +/- 40 s; d = 0.41) or NIT + SHAM (1455 +/- 47 s; d = 0.28) compared to PLA + SHAM (1469 +/- 52 s). These findings demonstrate that exposure to UV-A light alone does not alter the physiological responses to exercise or improve performance in a laboratory setting. A combination of UV-A and NIT, however, does improve cycling TT performance in this environment, which may be due to a larger increase in NO availability.
There is a demand for effective training methods that encourage exercise adherence during advancing age, particularly in sedentary populations. This study examined the effects of high-intensity interval training (HIIT) exercise on health-related quality of life (HRQL), aerobic fitness and motivation to exercise in ageing men. Participants consisted of males who were either lifelong sedentary (SED; N = 25; age 63 +/- 5 years) or lifelong exercisers (LEX; N = 19; aged 61 +/- 5 years). [Formula: see text] and HRQL were measured at three phases: baseline (Phase A), week seven (Phase B) and week 13 (Phase C). Motivation to exercise was measured at baseline and week 13. [Formula: see text] was significantly higher in LEX (39.2 +/- 5.6 ml kg min(-1)) compared to SED (27.2 +/- 5.2 ml kg min(-1)) and increased in both groups from Phase A to C (SED 4.6 +/- 3.2 ml kg min(-1), 95 % CI 3.1 - 6.0; LEX 4.9 +/- 3.4 ml kg min(-1), 95 % CI 3.1-6.6) Physical functioning (97 +/- 4 LEX; 93 +/- 7 SED) and general health (70 +/- 11 LEX; 78 +/- 11 SED) were significantly higher in LEX but increased only in the SED group from Phase A to C (physical functioning 17 +/- 18, 95 % CI 9-26, general health 14 +/- 14, 95 % CI 8-21). Exercise motives related to social recognition (2.4 +/- 1.2 LEX; 1.5 +/- 1.0 SED), affiliation (2.7 +/- 1.0 LEX; 1.6 +/- 1.2 SED) and competition (3.3 +/- 1.3 LEX; 2.2 +/- 1.1) were significantly higher in LEX yet weight management motives were significantly higher in SED (2.9 +/- 1.1 LEX; 4.3 +/- 0.5 SED). The study provides preliminary evidence that low-volume HIIT increases perceptions of HRQL, exercise motives and aerobic capacity in older adults, to varying degrees, in both SED and LEX groups.