The report also found communication skills are not up to scratch in many organisations. Only 49% of top leaders spend enough time communicating with staff, and just 52% of top leaders are rated for communicating clearly.
Viki Holton, research fellow, Ashridge Business School, and co-author of the research, said: "Talent management programmes and succession planning are essential. Without investment in developing the skills and experiences of younger managers it is hard to see how such organisations will continue to be successful.
"Businesses are at risk of holding back economic recovery by failing to do enough to develop the next generation of leaders."
However, despite these worries, 84% of managers said their organisation is well placed to "survive and thrive" post-recession.
Although more than half of the 1,100 managers surveyed said their organisation had suffered in the recession, nearly two-thirds said motivation and employee engagement levels were being sustained.
Other areas of change included a dramatic growth in virtual teams: 77% of managers said they are required to manage cross-functional and virtual teams. However, only 45% said their organisation provides sufficient support for virtual teamwork.
The research also found managers are overworked: over half of respondents (52%) said they felt ‘snowed under’ with too many emails and voicemails, and 66% of those who manage large teams said they felt overloaded.
The majority of respondents work longer than 48 hours each week and most managers (64%) regularly take work home.
Fiona Dent, director of executive education, Ashridge Business School, said: "There are signs of strain and pressure for many managers. One recommendation is to develop resilience among staff. Resilient people are more able to maintain a steady course when the economic, political and psychological weather deteriorates.
"Approaches to develop resilience include training and development, and establishing strong support networks."
The Ashridge Management Index (AMI) 2012/13, carried out by Ashridge Business School, is a barometer of workplace opinion which assesses the attitudes of over 1,100 managers in key areas of working life.