All participants will receive conventional physiotherapy for half an hour thrice weekly for six weeks. Conventional physiotherapy will be followed by a 15 min rest period, then the HIIT on a semi-recumbent cycle SOLE R92 (HIIT-RCE) will be performed.Each HIIT-RCE session will be preceded by 3-min of unloaded cycling as a warm-up and ended with 3-min of stretching. The HIIT-RCE procedure will start at 4-min at 30% of the peak workload interspersed with 1-min at 70% of the peak workload for weeks 1-2 (4 repetitions for 20 min) and increased by approximately 5 minutes every two weeks as tolerated to reach 30 minutes from week 5 (6 repetitions). The training intensity will progress similarly by 5% peak work rate two weeks as tolerated to reach 4-min at 40% peak workload interspersed with 1-min 80% peak workload from week-5. The cycle frequency will be at least 50 rpm.

The group will receive conventional physiotherapy that will consist primarily of passive movement, stretching, balance training, strengthening, and lower intensity overground walking for 30 minutes. This will be followed by a 15-minute rest period. Then an unloaded cycling session on a semi-recumbent cycle ergometer with preferred cadence until to get equal energy expenditure per session between groups by case-matching.

High-intensity interval training on semi-recumbent cycle ergometer

A progressive intensity maximal effort cycling test will be performed in a semi-recumbent ergometer cycle (SOLE R90) to determine each participant's peak workload (in watts).

The BBS will be used to assess balance impairment. It is a 14 item list with each item consisting of a five-point ordinal scale ranging from 0 to 4, with 0 indicating the lowest level of function and 4 the highest level of function. The minimum score is 0 and the maximum score is 56. A score of 56 indicates functional balance and a score < 45 indicates a higher risk of falling.