The chronic effects of a quantified jump-landing programme on bone health in premenopausal women.

This study will use a controlled trial experimental design implemented to determine the effects of a 12 month jump-landing programme (The formulation and design of the jump-landing programme utilised data gained from Study 1 in thesis) (Clissold et al. under review), intervention on parameters of bone health for premenopausal women. The jump-landing programme utilises the training principles and progression described for best practice in strength and conditioning. Data will be collected using dual energy X-ray absorptiometry (DEXA) utilising specialised hip structural analysis (HSA) software. Data will be compared using repeated measures ANOVA and effect statistics. Participants in the treatment group will be required to perform the regular (2-5 times/ week, with frequency increased progressively to allow for anatomical adaptation), jump-landing programme (in their own homes), and attend jump-landing group classes regularly (ideally weekly). The jump-landing exercise programme is expected to involve around 20 minutes to complete including a brief warm up and cool down, and can be performed at a time and place that suits the schedule of each participant. Participants will come into the laboratory on five occasions for data collection, which will involve around 1-2 hours for the familiarisation session and 1 hour for testing at 3, 6, 9 and 12 months. The following factors have been identified and discussed: The actual jump testing, and the jump-landing programme will carry minimal risk, as exercises selected are achieving the minimal threshold identified as producing osteogenic benefit to bone. All testing and jump training (supervised or unsupervised), will be preceded by warm up and mobilisation exercises, and these same exercises will be used to warm down the participant (to minimise any chance of post exercise muscle soreness). Participants will be excluded if: any medical problems are reported that compromise their participation or performance in this study: including having a recent or current musculoskeletal injury, osteoarthritis and any condition of impaired balance or coordination. Participants will also be excluded if they are pregnant. In addition, the exercise regime during the intervention period will be monitored via phone calls, text messages and emails, with participants encouraged to contact the researcher any time about any concerns or issues they might have. The training programme will include combinations made from the following jumps; 1) countermovement jump with reactive jump, 2) drop jump with reactive jump, 3) star jump with reactive jump, 4) stride jump with reactive jump, 5) countermovement vertical hop, 6) countermovement lateral hop, and 7) countermovement forward hop. It is proposed that this programme will increase in magnitude and rate of strain, number of ground contacts and technical difficulty (i.e. bilateral to unilateral) in a progressive manner over the 12 month period. The jumping programme will take no more than 20 minutes including a brief warm-up and cool down. Participants will be required to attend weekly group exercise sessions ( of 20 min duration) which will be run by qualified exercise trainers (jump-landing classes) and perform the same jump-landing programme in a group environment. This requirement is expected to positively affect compliance to the programme and provide a regular opportunity to monitor jumping proficiency and provide feedback to individuals when required to create a “club-like” environment (Wang et al., 2016). In addition adherence will be monitored using a register of attendance at group sessions and diary of home exercise completed, The jump-landing programme will utilise a model of periodisation to ensure that training principles are manipulated safely and effectively to achieve long-term benefit to bone health. Hence the concept of clustering the jumps will be explored to optimise the osteogenic effect over time whilst adhering to safe programming guidelines. The proposed programme will progress in volume and technical difficulty over the 12 months (in an individualised manner to reflect safety and proficiency of the participants), and its development will be based on previous studies which have safely achieved enhanced bone mineral density in premenopausal women over similar time periods. The loading of each mesocycle (4-week block of training), will utilise a 3:1 structure involving a progressive increase in jumping volume (loading) over the first 3 weeks, followed by a de-loading week characterised by low volume to enhance bone and muscular adaptations and provide opportunity for bone to re-sensitise before introducing a new jumping stimulus (Bompa & Haff, 2009; Fleck & Kraemer, 2014; Haff & Triplett, 2015). eg. Phase 1: Initial Adaptation (weeks 1-4) will involve performing the jump-landing programme 2-3 X week (2-3 sets of 5 maximal countermovement jumps, 20-42 total jump-landings, with 30 sec rest between sets). Phase 2: Bilateral 1 (weeks 5-8) will involve performing the jump-landing programme 3 X week (3 sets of 4-5 maximal countermovement jumps, 48-60 total jump-landings, with 30 sec rest between sets). Phase 9: Unilateral and Bilateral 7 (weeks 49-52) will involve performing the jump-landing programme 5 X week (2-3 sets of 5-6 maximal drop jumps (20cm), vertical and lateral hops, 50-60 total jump-landings, with 30 sec rest between sets). Please note that the participants progression between phases will be monitored by trained exercise specialists. The regular assessment of participants performing the jump-landings at the group jump-landing classes, and regular testing sessions, will allow for modification and further individualisation of the jump-training programme based on criteria set for safety and proficiency.