Table 3 Research gaps identified through the guideline development process

Research needs arising from systematic reviews

• Overall, there is a need for high-quality studies with strong designs (e.g., randomized controlled trials or longitudinal studies, larger sample sizes, objective measures).

• To enable comparison across studies, objective measures of sedentary behaviour, physical activity, and sleep (e.g., accelerometry, inclinometry) are needed. Additionally, there is a need to standardize measurement procedures.

• To establish the true effect of sedentary behaviour, physical activity, and sleep, possible confounders (e.g., diet) need to be controlled for in studies.

• To understand possible dose-response relationships between health outcomes and movement behaviours, examination of the effect of different doses (i.e., duration, frequency) of physical activity, sedentary behaviour, and sleep on health outcomes is needed (e.g., the effect of participating in physical activity for 15 min/day versus 30 min/day versus 60 min/day) and baseline physical activity should be controlled in intervention studies.

• Studies in infants and toddlers are required to establish developmentally-appropriate doses of sedentary behaviour and physical activity for these age groups.

• Examination of the associations between physical activity and psychosocial health, fitness, bone and skeletal health, cardiometabolic health, and risk/harms are needed.

• Examination of the associations between sedentary behaviour and bone and skeletal health, cardiometabolic health, fitness, and risks/harms are needed.

• Exploration of the associations between total sedentary time and health outcomes as well as patterns of sedentary behaviour (e.g., combination of timing, length, order of sedentary behaviours relative to physical activity and sleep, and breaks in sedentary behaviours) and health outcomes are needed;

• Studies examining the impact of new screen-based devices (e.g., mobile phones, tablets) and other common sedentary behaviours (e.g., reading, puzzles) on health outcomes are needed.

• Examination of the associations between sleep and motor development, growth, cardiometabolic health, and risk/harms are needed.

• Given the notable differences in development during the early years, studies focusing on sleep should report results based on narrow age ranges (i.e., newborns, infants, toddlers, and preschoolers).

• There is a need to determine the distribution of daily movement behaviours for optimal health throughout the early years, more specifically a need for studies that use more balanced approaches to intervene on various movement behaviours in the early years.

• Examination of the relationships between combinations of movement behaviours and health indicators is needed.

Research needs arising from Guideline Development Panel meetings and discussions

• Physical Activity

 ◦ Whether the environment in which physical activity takes place (e.g., indoor vs. outdoor) influences the relationships with health indicators is unclear; using accurate measures to capture physical activity dose together with context is recommended (e.g., combining objective measures of physical activity with time-use diaries).

 ◦ Explore the differences between types and context (e.g., outdoors, organized, social) of physical activity and their association with health.

 ◦ The effects of light-intensity physical activity on health indicators in the early years remain unclear. There is need to examine whether activities at the higher end of light physical activity are more beneficial for health than those at the lower end of light physical activity.

• Sedentary Behaviour

 ◦ Some time spent sedentary may be required to enhance growth and development. The need for a minimum amount of sedentary time to improve growth and development remains to be determined.

 ◦ There is a need for the use of valid and reliable measures of sedentary behaviour in the early years (e.g., inclinometers). In addition, valid and reliable tools to measure sedentary behaviour in non-ambulatory infants need to be developed.

 ◦ Establish whether the effect of screens on several health outcomes is due to the use of screens or the lack of movement.

 ◦ Explore the effects of different types of sedentary behaviour content (e.g., educational vs recreational screen time) on different health indicators.

• Sleep

 ◦ Research studies focusing on sleep quality are needed (e.g., sleep efficiency, sleep consolidation, sleep architecture).

 ◦ Identify optimal ranges of sleep duration for the different age groups. Studies examining the effect of different sleep durations on health outcomes are required.

 ◦ Examine the effect of sleep routines (e.g., consistent bed/wake times, screen time before bed) on sleep quantity and quality.

• Integrated movement behaviours

 ◦ No cause-effect evidence exists with regard to 24-h movement patterns. Longitudinal and experimental studies are needed.

 ◦ Exploration of different health indicators (e.g., school readiness) that may be uniquely important during the early years.

 ◦ Identify additional methods for analyzing 24-h movement data.

Stakeholder, intermediary, and end-user consultation and engagement research needs

• There is a need to understand more completely the language and delivery mediums and methods that minimize end-user feelings of guilt and disengagement and maximize motivation and empowerment to implement and achieve the integrated guidelines.

• There is a need to understand the nuances of guideline messaging to effectively and efficiently implement and activate the new guidelines in different end-user groups (e.g., parents, grandparents, child care providers, health care providers, early childhood educators).

International and inter-jurisdictional research needs and opportunities

• The dissemination, activation, implementation, impact, and uptake of the new integrated guidelines in different jurisdictions should be examined and compared.

• Intra- and inter-jurisdictional acceptance of the new integrated guidelines approach should be assessed and compared.

Other research needs

• There is a need for cost-effectiveness analyses of interventions aiming to improve movement behaviours during the early years.

• There is a need to increase the evidence on movement behaviours and health outcomes in young children with physical or mental diseases or disabilities.