Assessing Safety and Treatment Efficacy of Running On Intervertebral Discs (ASTEROID)

Three unsupervised community-based 30-minute exercise training sessions per week for 12 weeks prescribed by an accredited exercise physiologist from the research team. The setting in where the intervention will be performed is outdoors within the participants local community (e.g. walking/running track, local sports oval). Participants will require a mobile device and the RunKeeper app (ASICS Runner App, Inc.) to guide run/walk intervals and track exercise training data (i.e. speed, duration). As the intervention will be performed in the community, no additional equipment will be required. Exercise training sessions will be individualised based on participant capacity and rating of perceived exertion determined during a 30-minute initial assessment. Exercise training sessions will consist of a 5-minute general warm up followed by interval-based locomotive cardiovascular exercise training (e.g. walking or jogging) and will be progressed weekly as guided by an accredited exercise physiologist from the research team. Participants will receive educational content throughout the intervention covering how to safely exercise and avoid injury. Participants will receive educational materials through an online questionnaire database (RedCap), which is anonymously linked to each participant. Educational content will be provided to the participants fortnightly over the first eight weeks of the intervention. Educational material will cover the following topics: ideal running speed, footwear selection, benefits of running/physical activity and dealing with setbacks. The education materials will be designed specifically for the study by accredited exercise physiologists, with the aim of increasing adherence and minimising attrition. Educational materials are expected to take less than five minutes to review. Weekly 15-minute video calls with a member of study team to discuss exercise training program. Weekly video calls will discuss how progress/regress the program as required, adherence, any adverse effects and any other concerns or questions participants may have about the program or their low back pain. Adherence to the educational content will be monitored during the weekly zoom meeting by asking the participant: 'Have you read the educational content RE: 'X'. Can I answer any questions you may have?' The cardiovascular exercise program will consist of short running intervals interspersed with rest periods of walking. The rest periods between running intervals start at 115-120 seconds (depending on start point) and decrease by 15-25 seconds at each stage down to a possible minimum of 15 seconds. This type of interval-based training is an effective way to increase running capacity in untrained novice runners and is recommended following hip and lower limb injuries as a way to safely return to running. Participants enter the interval training program at stage one, two or three as determined by their performance on a 2-minute run test at the initial physical assessment. During the test participants will be instructed to run at a slow to moderate pace for as long as they are comfortable up to a maximum of two minutes. A slow or moderate running pace will be defined as less 10km per hour (6 mins/km). This is likely to translate to a running speed that is optimal to influence the intervertebral discs. Participants who can jog comfortably for: 1) 0-44 seconds will start at stage one of the program; 2) 45-89 seconds will start at stage two of the program; and 3) 90-120 seconds will start at stage three of the program. If preferred, participants also have the option to choose their starting point (stage one, two or three) in consultation with the accredited exercise physiologist irrespective of the test results. Each stage will consist of 6-10 repeats (participant to choose) with the running interval duration starting at 15-45 seconds (depending on start point) and increasing by 15 seconds each stage up to a maximum of 210 seconds. For example, at stage two, participants can select to complete between six and 10 repeats of 30 seconds jogging. This accounts for the daily fluctuations in pain intensity observed in up to 35% of individuals with chronic low back pain while promoting self-efficacy through autonomy and shared decision making. Once participants can complete the upper repeat range in each week, they progress to the next stage the following week. To reduce risk of injury due to the rate of progression, participants can only increase one stage per week and must complete at least two sessions per week before progressing to the following stage. The increase in average running time per week is greater over the first six weeks (20-100%) due to a conservatively chosen starting point (i.e. 1.5 mins total jogging time per session at stage one) before levelling off to increases of approximately 10-15% thereafter. Importantly, in novice runners there is no difference in the prevalence of running related injuries between training programs that adhere to a strict 10% weekly increase and those that include greater weekly progressions up to 50%. If participants reach the final stage before the end of the intervention, they will remain at this stage for the remaining weeks. Throughout the intervention participants will be advised to jog at a slow to moderate pace which corresponds with velocities thought to have a positive stimulus on the intervertebral disc, with higher running speeds correlated with poorer disc health outcomes. In collaboration with the accredited exercise physiologist, participants will have the option to regress to an earlier stage of the interval program if deemed necessary (e.g. significantly increased low back pain, other injury/soreness, following periods of poor adherence). Sessions recorded in the RunKeeper app will be reviewed by an accredited exercise physiologist. Subjective recall of completed sessions will also be recorded during the weekly zoom meetings.