Effects of cold ambient on self-selected cadence and efficiency

Although there are limited studies focused on metabolic and physiological adaptations on different ambient, muscle activations, optimal cadence or efficiency, there is no any study interested in freely choosing cadence (FCC) and mechanical efficiency (ME). Thus, the aim of the present study was to observe the effects of cold ambient (CA) on FCC and ME. 10 male moderately trained cyclists and triathletes volunteered for this study (V ̇O2max: 57.3 ± 4.2 mL∙min-1∙kg-1). Following familiarization session, athletes performed submaximal and maximal graded exercise tests, and then, three constant-load submaximal exercise bouts continued 20 minutes were conducted at wattages corresponding to 60% of V ̇O2max by using electromagnetically braked cycle ergometer in a climatic chamber. The submaximal exercise bouts consisted of i) normal ambient-FCC (NFCC; 20.1 ± 0.6°C, 60.8 ± 8.5% rh), ii) cold ambient-individually fixed to cadence used at NFCC (CFIXED, 8.4 ± 0.5°C, 64.9 ± 4.7% rh) and iii) cold ambient-FCC (CFCC, 8.1 ± 0.3°C, 66.9 ± 2.4% rh) were conducted with one day intervals. ME was calculated by external power output (Wattages) and the formula of metabolic power described by Garby and Astrup (1987). Skin temperature (Tskin) was measured by thermal camera while Tcore was recorded the ingestible core temperature sensor. Ambient temperature, humidity, oxygen and carbon-dioxide were automatically under-control by a climatic chamber. Main results showed that CFCC was 7% increase, when compared to NFCC (104.4 vs. 97.8 rpm, respectively; p=0.002). This change was 2.1% decrease in ME. When the NFCC was fixed to evaluate CFIXED, ME was 6.4% decrease from 18.8% to 17.6% (p=0.002). When cadence was allowed to participants' individual chose in cold ambient condition, it increased from 97.3 to 104.4 rpm with a concomitant increase in 4.4% of ME (17.6% vs. 18.4%, respectively; p=0.024). In addition, while Tcore linearly increased till the end of the exercise bouts in CFCC, NFCC and CFIXED (p=0.05), Tskin decreased throughout the exercises in CFCC and CFIXED (p=0.05); however, Tskin decreased in the first 6 minutes, and then gradually increased in NFCC (p=0.05). In conclusion, it should be allowed self-selected and relatively higher cadence rates in cold ambient conditions may increase cycling performance when compare to try to fix it.