More injuries were cause during training than in any other activity for full-time members of the Armed Forces, figures show.
In 2017/18, 52% of total injuries amongst the UK Armed Forces occurred in training – with 13% of those taking place on adventure training, according to Ministry of Defence statistics.
The figures were published just days after families called on the Ministry of Defence to be stripped of its immunity from prosecution after two SAS servicemen were acquitted of negligently performing a duty over a march in which three reservists died.
Lance Corporal Craig Roberts, 24, and Lance Corporal Edward Maher, 31, were pronounced dead on the Welsh mountain range after suffering heatstroke on July 13 2013.
Corporal James Dunsby, 31, died at Birmingham’s Queen Elizabeth Hospital from multiple organ failure more than two weeks later.
The soldiers were part of a group of 37 reservists and 41 regular troops taking part in the 16-mile test march in the Brecon Beacons, which had a time limit of eight hours and 48 minutes.
Two servicemen, known only as 1A and 1B, were acquitted of negligently performing a duty by failing to take reasonable care for the health and safety of the candidates.
Judge Advocate General Jeff Blackett found that 1A, a serving captain, and 1B, a former warrant officer, had no case to answer and said the deaths were caused by failures by Joint Forces Command, part of the Ministry of Defence.
‘The statistics are a disgrace’
Clare Stevens, partner at JMW Solicitors and military injury legal specialist - who has represented members of two of the reservists' families, said the MoD figures are a "disgrace".
She said: "Following in the wake of the SAS Court Martial this week, these figures are nothing less than damning for the MoD - never before has it been so important that immunity from prosecution be removed.
"The statistics really are a disgrace - 52% of the total incidents took place during training."
The MoD health and safety report said 28% of the injury and ill-health incidents in 2017/18 were Riddor reportable.
Riddor puts a duty on employers to report certain serious workplace accidents, occupational diseases and specified dangerous occurrences (near misses).
‘No lessons have been learned’
Training (including adventure training) was the event with the greatest percentage of injury incidents amongst UK Regular Armed Forces personnel (52%), followed by Normal Duties (26%) and then Sport/Recreation (22%).
Within the 52% figure for training injuries - 3,384 injuries - a total of 441 injuries (13%) took place on adventure training, 444 (13%) on exercise, and 896 (26%) during physical training which includes endurance training.
Ms Stevens added: "If ever there were proof that the MoD is unable, or unwilling, to act on past failures, this is it - clearly no lessons have been learned and tragedies will continue to happen.
"A career in the military is never going to be without risk, and training of course has to be realistic, however for the rate of injury to increase so significantly is simply not acceptable.
"Servicemen and women who are willing to make huge sacrifices for their country deserve better - the number of personnel we are seeing suffering serious injury and devastating loss of career through poor equipment, inadequate training or risk assessment cannot be justified."
An MoD spokeswoman said: "We offer extensive training to our brave Armed Forces who do a vital and sometimes dangerous job.
"It is therefore not surprising a significant proportion of accidents occur during training as this is where our troops spend vast amounts of their time.
"When our personnel have suffered an injury due to their service, we provide wide ranging support and guidance to ensure they get back to full fitness as quickly as possible."