Multiple sclerosis exercise mode and intensity study

The main purpose of the study will be to assess exercise capacity, cardiorespiratory and power outcomes on two modes of exercise during three different exercise protocols. The results will allow us to understand how to elicit higher intensities of exercise in people with advanced multiple sclerosis (MS). Familiarization: Participants will perform six familiarization sessions with functional electrical simulation (FES) cycling and arm crank ergometry (ACE). Electrical stimulation will be applied via gel electrodes on the front and back of the quadriceps, hamstring, and gluteal muscle groups to cause these muscles to contract and pedal the stationary cycle. Each familiarization session will be 1.5 hours in duration, including set up and exercise. These sessions will be performed prior to the exercise trials over a three to six week period and the final session will occur in the week before the first exercise trial. The electrical stimulation will be increased over 10 minutes in each session to a level at which can be tolerated by each participant. Participants will then arm crank exercise for 20 minutes. This will include two sessions of each exercise trial, that is, 20 minutes exercise at a rate of perceived exertion (RPE) of 12 – 13, interval exercise with 60 second work and 30 seconds rest at a RPE of 14 – 17 and interval exercise with 4 minutes work and 3 minutes rest at a RPE of 14 – 17. For each exercise capacity test and exercise trial, the electrical stimulation will be increased over 10 minutes for the FES trials and will remain at 100% of the pre-determined maximum stimulation tolerated during familiarization. Each session will be supervised by an Exercise and Sports Science Australia Accredited Exercise Physiologist. Each trial will be separated by three days to one week. Exercise capacity tests: Participants will perform two incremental exercise tests in a randomized order to determine peak VO2 and power. Exercise modes will include ACE and ACE combined with FES cycling (hybrid FES cycling). Exercise trials: Participants will perform six exercise trials in a randomized order with cardiorespiratory measures (such as VO2, heart rate) and power as the main outcome measures. An average of the peak power data obtained in the ACE incremental test and hybrid FES cycling incremental test will be used to determine the percentage of peak arm crank Watts to be performed in Hybrid and ACE trials. These percentages of peak workload have been chosen to ensure the same amount of total arm crank work (Watts x time) is performed during each trial. 1. Hybrid FES cycling continuous trial: 10 mins of FES increase, then 20 minutes comprising: 20 minutes arm cranking at 45% of peak arm crank power, 12-13 RPE, FES at 100% tolerance 2. Hybrid FES cycling interval trial 1: 10 mins of FES increase, then 14.5 minutes comprising: 60 seconds work / 30 seconds passive rest, 90% of peak arm crank power, 10 intervals (i.e. repetitions) of work/rest, 14 – 17 RPE, FES at 100% tolerance 3. Hybrid FES cycling interval trial 2: 10 mins of FES increase, then 25 minutes comprising: 4 minutes arm crank work (60 sec work at 75% peak arm crank power / 60 sec work at 85% peak arm crank power / 120 sec work at 90% peak arm crank power), 3 minutes passive rest between work period, 4 repetitions of work/rest, 14 – 17 RPE, FES at 100% tolerance 4. ACE continuous trial: 20 minutes comprising: 20 minutes arm cranking at 45% of peak arm crank power, 12-13 RPE 5. ACE interval trial 1: 14.5 minutes comprising: 60 seconds work/ 30 seconds passive rest, 90% of peak arm crank power, 10 repetitions of work/rest, 14 – 17 RPE 6. ACE interval trial 2: 25 minutes comprising: 4 minutes arm crank work (60 sec work at 75% peak arm crank power / 60 sec work at 85% peak arm crank power / 120 sec work at 90% peak arm crank power), 3 minutes passive rest between work period, 4 repetitions of work/rest, 14 – 17 RPE Participants will be familiarized to FES cycling, arm cranking and RPEs prior to the exercise trials. Participants will be instructed and encouraged to achieve target power and RPE outcomes during the exercise trials.