By Mat Popovich and TCR Sport Lab
Running, as a sport, has been gaining significant popularity over the past decade (Rizzo, 2021). Running dynamics can be analyzed using various metrics including ground contact time, vertical oscillation, stride length, and cadence (Adams et al., 2016). Running cadence is defined as the number of steps taken per minute and may be referred to as various terms, including stride frequency. Running cadence has become a more accessible measurement than ever before due to the availability of wearable technology (e.g., running watches), that allow for simple, valid, and reliable at-home measurement of running cadence (Adams et al., 2016). With the increasing popularity of running and the increased accessibility of measuring running cadence, the effect of cadence on running performance is something that should be considered.
Running economy (RE) is a running performance metric, defined as the amount of energy needed (measured as the rate of oxygen uptake (V̇O2)) to sustain a given submaximal running speed (Saunders et al., 2004). RE has been researched far less than other factors that determine running performance, such as V̇O2max and the ability to sustain a high percentage of V̇O2max for an extended period (Foster & Lucia, 2007). Although overlooked, RE is an important metric to consider when analyzing running performance for runners looking to get an edge up on their competition.
Running dynamic values have been shown to influence running economy (Williams & Cavanagh, 1987). The relationship between V̇O2 and stride length was analyzed by Cavanagh and Williams (1982) as well as Hogberg (1952). Stride length is inversely related to cadence, meaning that as one is increased the other decreases for the same given speed. Cavanagh and Williams (1982) showed that an optimal stride length exists where V̇O2 is lowest at the same given speed, and was similar to the self-selected stride length of each participant. The authors also found that deviating from the optimal stride length only caused a relatively small change in V̇O2, which was noted to possibly be due to the highly experienced runners used in their experiment. The current study looks to examine how the related variable, running cadence, affects running economy, and whether varying cadence affects economy at the same speed, in intermediate level runners.
The current study explores the effects that three different cadences, including a self-selected cadence, have on V̇O2 and related variables at the same relative speed and the interindividual differences in the optimal cadence. The present study will examine four intermediate level runners as opposed to the highly trained participants used by Cavanagh and Williams (1982). It is hypothesized that there will be a difference in which cadence is optimal, and that the self-selected cadence will be the most economical cadence for most participants.
The figures below represent the comparison of each participants’ V̇O2, % fat oxidation, respiratory rate, minute ventilation, and heart rate at their self-selected cadence (SS), self-selected subtract 7% cadence (SS-7%), and self-selected plus 7% cadence (SS+7%). See Figures 1, 2, 3, 4, and 5 below.
Discussion
The current study explored the effects of various running cadences on V̇O2 and related variables in intermediate runners and the interindividual differences in optimal cadence. Overall, SS was the most economical cadence on average as hypothesized. These reults are consistent with those in the literature (Cavanagh & Williams, 1982). On average SS+7% was the highest % fat oxidation, indicating that participants were burning more fat than carbohydrate while running at the faster cadence. This is intriguing due to a higher fat oxidation being associated with lower intensity efforts (Coyle, 1995), meaning that the participants may have felt that SS+7% was easier to maintain even though the speed at which they were running at was the same.