In this yoga path, there is no loss of effort, nor any adverse outcome. Even a small measure of this yogic pursuit will save one from mighty fear.
Krishna speaks about two dangers, which the performance of action involves any time. They are called abhikrama-nāśa and pratya-vāya. The first one refers to loss of whatever effort is made to achieve the desired outcome for the act. Pratya-vāya denotes adverse result. Both are inherent in the performance of activities.
Loss of effort is common in the field of agriculture. The crop raised by sowing seeds, nurtured with care, caution and nutrition, is suddenly affected by pests, drought, floods, etc. It renders the efforts made a total waste.
Pratya-vāya, adverse result, is common in medical treatment. Sometimes a drug wrongly given can prove fatal.
In spite of all precautions, these two possibilities can never be safeguarded against fully. But in the case of the outcome of Karma-yoga, says Krishna, both the fates are not there at all. The result is immediate and experiential.